Geobiology 2013 Lecture 5 Biogeochemical Tracers

Isotopics 2 C H O and N Acknowledgements John Hayes Karen Casciotti Steve

Macko John Hedges

Assigned Reading bull Stanley 2nd Ed Chapter 10 pp 221-240

bull Hayes JM 2001 Fractionation of the isotopes of carbon and hydrogen inbiosynthetic processes Reviews in Mineralogy Stable IsotopicGeochemistry John W Valley and David R Cole (eds)

bull Hayes Concepts and Calculations

1

Geobiology 2012 Lecture 5 Biogeochemical Tracers

Isotopics 2 C H O and N Need to Know

Ballpark delta values of C O N H in marine and terrestrial biomass

How HampO are fractionated in the hydrological cycle

How (roughly) CampH fractionation occurs in organic matter

How (roughly) N is fractionated on land and in the ocean

2

Sources of hydrogen and oxygen isotopic fractionation

3

0

Fraction of remaining vapor

10 075 050 025 0

0

-5

-10

-15

-20

-25

Condensate

Vapor

9

11

0

0

20 15 10 0 -20 -30

Cloud temperature (oC)

Figure by MIT OpenCourseWare

The major nonbiological fractionation process affecting stable hydrogen (and oxygen) isotopes is the hydrologic cycle in which water molecules containing lighter isotopes

Image removed due to copyright restrictions (1H amp 16O) are preferentially evaporated and retained in a Graph of deuterium per mil over oxygen-18 per mil cloud (vs 2H amp 18O)

The net result of this fractionation process is that precipitation at increasingly inland higher altitude (cooler) sites is depleted in both 18O and 2H (D)

4

-130

Vapor-150

Vapor-170

Vapor-30

Rain-50

Rain

ContinentOcean

0

Figure by MIT OpenCourseWare

Courtesy of John Hayes Used with permission

In general tree sap isotopically resembles local meteoric water whereas leaf water is isotopically enriched Organic matter is depleted in D versus the leaf water from which it is biosynthesized (values given above are typical for N American plants)

In general lipids are depleted in D versus lignin and cellulose from the same plant whereas cellulose is slightly more depleted than coexisting lignin (Rundle et al 1989)

Cellulose is usually analyzed in nitrated form (NO3 replacing OH on each C) so that only the nonexchangeable H directly bound to C is analyzed

Because the D in cellulose nitrate reflects local water woods can be used as a proxy for the hydrogen isotope composition of past environments in which the wood was made

5

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Geobiology 2012 Lecture 5 Biogeochemical Tracers

Isotopics 2 C H O and N Need to Know

Ballpark delta values of C O N H in marine and terrestrial biomass

How HampO are fractionated in the hydrological cycle

How (roughly) CampH fractionation occurs in organic matter

How (roughly) N is fractionated on land and in the ocean

2

Sources of hydrogen and oxygen isotopic fractionation

3

0

Fraction of remaining vapor

10 075 050 025 0

0

-5

-10

-15

-20

-25

Condensate

Vapor

9

11

0

0

20 15 10 0 -20 -30

Cloud temperature (oC)

Figure by MIT OpenCourseWare

The major nonbiological fractionation process affecting stable hydrogen (and oxygen) isotopes is the hydrologic cycle in which water molecules containing lighter isotopes

Image removed due to copyright restrictions (1H amp 16O) are preferentially evaporated and retained in a Graph of deuterium per mil over oxygen-18 per mil cloud (vs 2H amp 18O)

The net result of this fractionation process is that precipitation at increasingly inland higher altitude (cooler) sites is depleted in both 18O and 2H (D)

4

-130

Vapor-150

Vapor-170

Vapor-30

Rain-50

Rain

ContinentOcean

0

Figure by MIT OpenCourseWare

Courtesy of John Hayes Used with permission

In general tree sap isotopically resembles local meteoric water whereas leaf water is isotopically enriched Organic matter is depleted in D versus the leaf water from which it is biosynthesized (values given above are typical for N American plants)

In general lipids are depleted in D versus lignin and cellulose from the same plant whereas cellulose is slightly more depleted than coexisting lignin (Rundle et al 1989)

Cellulose is usually analyzed in nitrated form (NO3 replacing OH on each C) so that only the nonexchangeable H directly bound to C is analyzed

Because the D in cellulose nitrate reflects local water woods can be used as a proxy for the hydrogen isotope composition of past environments in which the wood was made

5

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Sources of hydrogen and oxygen isotopic fractionation

3

0

Fraction of remaining vapor

10 075 050 025 0

0

-5

-10

-15

-20

-25

Condensate

Vapor

9

11

0

0

20 15 10 0 -20 -30

Cloud temperature (oC)

Figure by MIT OpenCourseWare

The major nonbiological fractionation process affecting stable hydrogen (and oxygen) isotopes is the hydrologic cycle in which water molecules containing lighter isotopes

Image removed due to copyright restrictions (1H amp 16O) are preferentially evaporated and retained in a Graph of deuterium per mil over oxygen-18 per mil cloud (vs 2H amp 18O)

The net result of this fractionation process is that precipitation at increasingly inland higher altitude (cooler) sites is depleted in both 18O and 2H (D)

4

-130

Vapor-150

Vapor-170

Vapor-30

Rain-50

Rain

ContinentOcean

0

Figure by MIT OpenCourseWare

Courtesy of John Hayes Used with permission

In general tree sap isotopically resembles local meteoric water whereas leaf water is isotopically enriched Organic matter is depleted in D versus the leaf water from which it is biosynthesized (values given above are typical for N American plants)

In general lipids are depleted in D versus lignin and cellulose from the same plant whereas cellulose is slightly more depleted than coexisting lignin (Rundle et al 1989)

Cellulose is usually analyzed in nitrated form (NO3 replacing OH on each C) so that only the nonexchangeable H directly bound to C is analyzed

Because the D in cellulose nitrate reflects local water woods can be used as a proxy for the hydrogen isotope composition of past environments in which the wood was made

5

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

0

Fraction of remaining vapor

10 075 050 025 0

0

-5

-10

-15

-20

-25

Condensate

Vapor

9

11

0

0

20 15 10 0 -20 -30

Cloud temperature (oC)

Figure by MIT OpenCourseWare

The major nonbiological fractionation process affecting stable hydrogen (and oxygen) isotopes is the hydrologic cycle in which water molecules containing lighter isotopes

Image removed due to copyright restrictions (1H amp 16O) are preferentially evaporated and retained in a Graph of deuterium per mil over oxygen-18 per mil cloud (vs 2H amp 18O)

The net result of this fractionation process is that precipitation at increasingly inland higher altitude (cooler) sites is depleted in both 18O and 2H (D)

4

-130

Vapor-150

Vapor-170

Vapor-30

Rain-50

Rain

ContinentOcean

0

Figure by MIT OpenCourseWare

Courtesy of John Hayes Used with permission

In general tree sap isotopically resembles local meteoric water whereas leaf water is isotopically enriched Organic matter is depleted in D versus the leaf water from which it is biosynthesized (values given above are typical for N American plants)

In general lipids are depleted in D versus lignin and cellulose from the same plant whereas cellulose is slightly more depleted than coexisting lignin (Rundle et al 1989)

Cellulose is usually analyzed in nitrated form (NO3 replacing OH on each C) so that only the nonexchangeable H directly bound to C is analyzed

Because the D in cellulose nitrate reflects local water woods can be used as a proxy for the hydrogen isotope composition of past environments in which the wood was made

5

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Courtesy of John Hayes Used with permission

In general tree sap isotopically resembles local meteoric water whereas leaf water is isotopically enriched Organic matter is depleted in D versus the leaf water from which it is biosynthesized (values given above are typical for N American plants)

In general lipids are depleted in D versus lignin and cellulose from the same plant whereas cellulose is slightly more depleted than coexisting lignin (Rundle et al 1989)

Cellulose is usually analyzed in nitrated form (NO3 replacing OH on each C) so that only the nonexchangeable H directly bound to C is analyzed

Because the D in cellulose nitrate reflects local water woods can be used as a proxy for the hydrogen isotope composition of past environments in which the wood was made

5

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Hydrogen isotopic signatures Fd-NADP reductase (24)Photosynthesis H2O + hv O2 + NADPH

2 reduced ferredoxin + NADP+ + H+ 2 oxidized ferredoxin + NADPH

Insertion of a non-exchangeable H- from NADPH into pyruvate

Reactions like this responsible for setting δD of organics

H going from NADPH to pyruvate becomes H in lipid

6

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

WATER 0

Cellulose

Reproc Production amp Exch of NADPH

-100 Starch

ExportedPhotosynthate

Reproc amp Exch

D =

Photosynthate

Cytosol-200 Chloroplast

Relationships between the hydrogen isotopic compositions of initial photosynthate and related products and of water available within plant cells The uncertainty indicated on the pathway between water and photosynthate reflects the possibility of offsetting fractionations in the production of NADPH and the subsequent transfer of H - to photosynthate

Hydrogen isotopic signatures inherited from water through

reactions of NADPH

Figure by MIT OpenCourseWare

7

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

-150 -100 -50 0

-340

-320

-300

-280

-260

-240

-220

-200

-180

=197

HO

Figure by MIT OpenCourseWare

8

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Sources of nitrogen isotopic fractionation

9

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Simplified Terrestrial Nitrogen Cycle

httpwwwwindowsucareduearthclimateimagesnitrogencyclejpg

Bottom line In natural systems new fixed nitrogen entering the system comes from bacterial nitrogen fixation which results in only small N-isotopic fractionations

10

Schematic figure of the nitrogen cycle removed due to copyright restrictions

Some Typical 15N values

Atm N2 lsquofixedrsquorsquo by terrestrial flora (Nif in legumes) ~ 0 per mil

Atm N2 lsquofixedrsquo by marine bacteria and Cb ~ 0 per mil

Nitrate or ammonium utilized by terrestrial flora and converted to organic nitrogen ~0 per mil

Dissolved nitrate in the ocean ~ +7 to +10 per mil

Marine organisms high in the trophic structure (eg fish whales)

+10 to + 20 per mil

11

Simplified Marine Nitrogen Cycle

copy Karen Casciotti OCW 12

N2 fixation CO2 Atmosphericdeposition

Dead organic matterExport production

New Production

Regeneratedproduction

NO3 -

NH4 +

NH4 +

CO2 + CO2 +

CO2 +DON DOC

Euphotic zone

Aphotic zone

Bacteria

Phytoplankton Zooplankton

Image by MIT OpenCourseWare

13

Major isotopic fractionation in the N-cycle occurs during denitrification (-20 to -40 per mil)

Light N2 leaves the ocean causing the residual nitrate to become heavy

14

U Weismann ldquoBiological nitrogen removal fromwastewaterrdquo Adv BiochemEngr 51113-154 (1994)

Nitrification NH4 + 15 O2 NO2 + H2O + 2H+ + -

-

- -

-lowers pH

escapes

NO2 + 05 O2 NO3

5 HOAc + 8 NO3 4 N2 + 10 CO2 + 6 H2O + 8 OH

Denitrification

MUST have carbon source eg acetate raises pH

Image by MIT OpenCourseWare

15N vs 13C Foodweb

Trophic fractionation of carbon and nitrogen isotopes (Georges Bank)

B Fry (1988) Limnol Oceanogr 33 1182-1190

15

15

16

17

18

19

20

10

11

12

13

14

5

01

2

3

4

6

7

8

9

-25 -20-21-22-23-24 -15-16-17-18-19

Phytoplankton

δ 13C (13C )

δ15

N (15

N )

POC

Invertebrates

Fish

Image by MIT OpenCourseWare

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

Simplified Marine Nitrogen Cycle

copy Karen Casciotti OCW 12

N2 fixation CO2 Atmosphericdeposition

Dead organic matterExport production

New Production

Regeneratedproduction

NO3 -

NH4 +

NH4 +

CO2 + CO2 +

CO2 +DON DOC

Euphotic zone

Aphotic zone

Bacteria

Phytoplankton Zooplankton

Image by MIT OpenCourseWare

13

Major isotopic fractionation in the N-cycle occurs during denitrification (-20 to -40 per mil)

Light N2 leaves the ocean causing the residual nitrate to become heavy

14

U Weismann ldquoBiological nitrogen removal fromwastewaterrdquo Adv BiochemEngr 51113-154 (1994)

Nitrification NH4 + 15 O2 NO2 + H2O + 2H+ + -

-

- -

-lowers pH

escapes

NO2 + 05 O2 NO3

5 HOAc + 8 NO3 4 N2 + 10 CO2 + 6 H2O + 8 OH

Denitrification

MUST have carbon source eg acetate raises pH

Image by MIT OpenCourseWare

15N vs 13C Foodweb

Trophic fractionation of carbon and nitrogen isotopes (Georges Bank)

B Fry (1988) Limnol Oceanogr 33 1182-1190

15

15

16

17

18

19

20

10

11

12

13

14

5

01

2

3

4

6

7

8

9

-25 -20-21-22-23-24 -15-16-17-18-19

Phytoplankton

δ 13C (13C )

δ15

N (15

N )

POC

Invertebrates

Fish

Image by MIT OpenCourseWare

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

13

Major isotopic fractionation in the N-cycle occurs during denitrification (-20 to -40 per mil)

Light N2 leaves the ocean causing the residual nitrate to become heavy

14

U Weismann ldquoBiological nitrogen removal fromwastewaterrdquo Adv BiochemEngr 51113-154 (1994)

Nitrification NH4 + 15 O2 NO2 + H2O + 2H+ + -

-

- -

-lowers pH

escapes

NO2 + 05 O2 NO3

5 HOAc + 8 NO3 4 N2 + 10 CO2 + 6 H2O + 8 OH

Denitrification

MUST have carbon source eg acetate raises pH

Image by MIT OpenCourseWare

15N vs 13C Foodweb

Trophic fractionation of carbon and nitrogen isotopes (Georges Bank)

B Fry (1988) Limnol Oceanogr 33 1182-1190

15

15

16

17

18

19

20

10

11

12

13

14

5

01

2

3

4

6

7

8

9

-25 -20-21-22-23-24 -15-16-17-18-19

Phytoplankton

δ 13C (13C )

δ15

N (15

N )

POC

Invertebrates

Fish

Image by MIT OpenCourseWare

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

Major isotopic fractionation in the N-cycle occurs during denitrification (-20 to -40 per mil)

Light N2 leaves the ocean causing the residual nitrate to become heavy

14

U Weismann ldquoBiological nitrogen removal fromwastewaterrdquo Adv BiochemEngr 51113-154 (1994)

Nitrification NH4 + 15 O2 NO2 + H2O + 2H+ + -

-

- -

-lowers pH

escapes

NO2 + 05 O2 NO3

5 HOAc + 8 NO3 4 N2 + 10 CO2 + 6 H2O + 8 OH

Denitrification

MUST have carbon source eg acetate raises pH

Image by MIT OpenCourseWare

15N vs 13C Foodweb

Trophic fractionation of carbon and nitrogen isotopes (Georges Bank)

B Fry (1988) Limnol Oceanogr 33 1182-1190

15

15

16

17

18

19

20

10

11

12

13

14

5

01

2

3

4

6

7

8

9

-25 -20-21-22-23-24 -15-16-17-18-19

Phytoplankton

δ 13C (13C )

δ15

N (15

N )

POC

Invertebrates

Fish

Image by MIT OpenCourseWare

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

15N vs 13C Foodweb

Trophic fractionation of carbon and nitrogen isotopes (Georges Bank)

B Fry (1988) Limnol Oceanogr 33 1182-1190

15

15

16

17

18

19

20

10

11

12

13

14

5

01

2

3

4

6

7

8

9

-25 -20-21-22-23-24 -15-16-17-18-19

Phytoplankton

δ 13C (13C )

δ15

N (15

N )

POC

Invertebrates

Fish

Image by MIT OpenCourseWare

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

Trophic fractionation of carbon and nitrogen isotopes

K Yoshii N G Melnick O A Timoshkin N A Bondarenko P N Anoshko T Yoshioka amp E Wada (1999) Limnol Oceanogr 44 502-511

16

δ15 N

(

)

δ13C ( )

1

2

3

4

-300 -290 -280 -270 -260 -240 -230-250

100

110

120

130

140

50

60

70

80

90

40

30

150

Pelagic sculpins

MesozooplanktonCyclops kolensis

Comephorusbaicalensis

Cottocomephorusinermis

Comephorusdybowskii

Cottocomephorusgrewingki

Juvenile ofpelagic sculpins

MacrozooplanktonAmphipod

Macrohectopusbranickii

MesozooplanktonEpischura baicalensis

PhytoplanktonAulacoseira baicalensis

Trophic Level

Pelagic fishCoregonus autumnalis

migratorius

Sealphoca sibirica

Image by MIT OpenCourseWare

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

Biogeochemistry of the Stable Nitrogen Isotopes An important use of stable nitrogen isotopes is as an indicator of trophic level in natural systems with known nitrogen sources and relatively simple food webs The following figure is from Schoeninger and DeNiro (1984) GCA 48 625-639 Average 815N trophic offset is ~3 permil per trophic level

Courtesy Elsevier InchttpwwwsciencedirectcomUsed with permission

17

Characterizing Organic Matter Using Bulk Isotopic Data

18

-20 -19 -18 -17 -16 7

8

9

10

11

α

Figure by MIT OpenCourseWare

19

Organismal Variability in Bulk C-Isotopes

20

-20 -25 -30

13Cpermil-15

Fractions of amarine plankton

Pectin

Total carbohydrate

Total organic matter

Cellulose

Lignin-like material

Lipids

Marine sediment

Degens 1969

Hemicellulose

Protein

Image by MIT OpenCourseWare

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

21

Characterising Cocaine Sources

These images have been removeddue to copyright restrictions

22

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

-20 -19 -18 -17 -16 7

8

9

10

11

α

Figure by MIT OpenCourseWare

19

Organismal Variability in Bulk C-Isotopes

20

-20 -25 -30

13Cpermil-15

Fractions of amarine plankton

Pectin

Total carbohydrate

Total organic matter

Cellulose

Lignin-like material

Lipids

Marine sediment

Degens 1969

Hemicellulose

Protein

Image by MIT OpenCourseWare

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

21

Characterising Cocaine Sources

These images have been removeddue to copyright restrictions

22

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

Organismal Variability in Bulk C-Isotopes

20

-20 -25 -30

13Cpermil-15

Fractions of amarine plankton

Pectin

Total carbohydrate

Total organic matter

Cellulose

Lignin-like material

Lipids

Marine sediment

Degens 1969

Hemicellulose

Protein

Image by MIT OpenCourseWare

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

21

Characterising Cocaine Sources

These images have been removeddue to copyright restrictions

22

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

21

Characterising Cocaine Sources

These images have been removeddue to copyright restrictions

22

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

Characterising Cocaine Sources

These images have been removeddue to copyright restrictions

22

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

-7 -6 -5 -4 -3 -2 -1 0 1 -40

-35

-30

-25

-20

-15

Synthetic

Biotechnological

Mexico Comores

Tahiti H

H

H

H

O

OH OMe

Figure by MIT OpenCourseWare

Co Is

Multi-element mpound-specific otopic Analyses Vanillin

23

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

Compound Specific Isotope Analysismz 44 mV

4544 ratio trace

Courtesy of John Hayes Used with permission

24

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

Reprinted by permission from Macmillan Publishers Ltd Katherine H FreemanJ M Hayes et al Evidence from Carbon Isotope Measurements for DiverseOrigins of Sedimentary Hydrocarbons Nature 343 (1990) 254-6

25

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

C-isotopic Composition of Organic Compounds

Three major controls

bull Source of carbon and its C-isotopiccomposition

bull Fractionation during assimilation (egheterotrophy photosynthesis methanotrophy)

bull Fractionation during biosynthesis (lipids)

26

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

C-isotopic Composition of Organic Compounds

Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

27

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

28

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

C-isotopic Composition of Organic Compounds bull  Fractionation during photosynthesis

Courtesy of John Hayes Used with permission

29

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

C-isotopic Composition of Organic Compounds Source of carbon and its C-isotopic composition

ndash Inorganic carbon bull (-7permil atm CO2) assimilated by photosynthesis

ε 5-35 per mil depending on pathway extent of consumption

ndash Organic carbon bull (-25permil on average) assimilated during heterotrophy

ε -1 (you are what you eat plus 1 per mil)

ndash Methane carbon bull (-30 to -100permil) assimilated during methanotrophy

ε 0-30 per mil depending on pathway and extent ofconsumption

30

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

httpwwwastrobionetnewsmodulesphpop=modloadampname=Newsampfile=articleampsid=34

At the very edge of the brine pool the mussels are especially abundant and happy This area is often filled with newly settled baby mussels perched on the shells of larger mussels just above the brine Credit Penn State University Dept of Biology

Cafeacute Methane

Gas hydrates (yellow) are ice with gas trapped inside exposed beds are accessible to submersibles on the deep sea floor of the Gulf of Mexico Ice worms a new species only seen in hydrate were discovered in 1997 by C Fisher Penn State University

31

httpwwwbiopsueduPeopleFacultyFishercold_seeps

Methane-rich water is pumped into the mussel and across its gills The symbiotic bacteria in the gills use methane as both a carbon and energy source The mussels in turn live off the symbiotic bacteria

Using the scanning electron microscope we can see over a dozen mussel gill cells in the panel on the left On the right is a closer look at the cell with its outer membrane partially removed Look into the cell to see hundreds of symbiotic bacteria

32

Using the scanning electron microscope we can see over a dozen mussel gill cells in the panel on the left On the right is a closer look at the cell with its outer membrane partially removed Look into the cell to see hundreds of symbiotic bacteria

33

34

CompoundοRemains

Total concn δ13C(microg g-1)b (o)c

Free sterols

Steryl esters

Hopanepolyols

Cholest-5-en-3β-ol

Cholest-5-en-3β-ol

C31 hopanol

C32 hopanol

Cholestan-3β-olCholesta-524-dien-3β-ol

Cholest-7-en-3β-ol

4-Methyl-cholesta-8(14)24-dien-3β-ol

4-Methyl-cholest-7-en-3β-ol

4-Methyl-cholesta-724-dien-3β-ol

Cholestan-3β-ol

Cholesta-524-dien-3β-ol

Cholest-7-en-3β-ol

4-Methyl-cholesta-dien-3β-ol

4-Methyl-cholesta-8(14)24-dien-3β-ol

4-Methyl-cholest-7-en-3β-ol

4-Methyl-cholesta-724-dien-3β-ol

4414-Trimethyl-cholesta-8(9)24-dien-3β-ol

4414-Trimethyl-cholesta-8(9)24-dien-3β-ol

1950

1520

135

150

130

106

52

24

ND

ND

ND

31

47

18

4

8

5

1

1

1

lt1

lt1

-710

-710

-737

-726

-751

-733

-717

NA

NA

NA

NA

NA

NA

NA

NA

-729

Gill tissueTotal concn δ13C(microg g-1)b (o)c

3460

222090

387

166

11

381

83

45

73

132

68

ND

ND

6

5

5

46

2

1040

828

212

-709

-728

-698

-728

-673

-742

-716-774

-754

-707

-685

NA

NA

NA

NA

-749

NAd

Mantle tissueTotal concn δ13C(microg g-1)b (o)c

-722

-715

-726

-695

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

-723

2750

2130

228124

132

NAd

53

57

25

ND

ND

ND

14

12

4

4

6

2

4

3

82

61

Tissue Distribution and δ13C Values for Seep Mussel Cyclic Triterpenoids

ldquoSterols and hopanols are listed in relative in order of elution from DB-5 columns and were ideatified bt a combination of TLC mobility on conventionaland silver-impregated plates relative retention times on DB-5 columns and the mass spectra of trimethylsilyl and acetate derivatives Trace amounts of cholest8(9)-en-3βminusol and a44-dimethyl monene were also detected in gill tissueThe 4-methyl-cholesta-724-dien-3β-ol may have an internal double bondat either C-7(8) or C-8(9) The C31 and C32 hopanols are products of cleavage of the polyhydroxylated side chains of the various BHP molecules (Fig 1) (45)

b Total amount of material recovered per gram (dry weight) based on the results of an analysis of isolated tissues obtained from a singal dissected mussel c δ13C values were determined by performing a compound-specific analysis for the acetate derivatives of individual hopanol and sterol compounds that werelarge enough to analyze The reporied δ13C values for the free hydroxyl and were calculated after we determined ampirically the isotope effect due to acetatederivative formationb NA not analyzedc NA compound not detected

- - -

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Image by MIT OpenCourseWare

35

Lanostane (XVIII δδ13C -70permil)hop-17-(21)-ene XII δ13C -32permil)

Norlanostane (XVII δδ13C -80permil)

Courtesy Elsevier Inc httpwwwsciencedirectcom Used with permission

36

34

CompoundοRemains

Total concn δ13C(microg g-1)b (o)c

Free sterols

Steryl esters

Hopanepolyols

Cholest-5-en-3β-ol

Cholest-5-en-3β-ol

C31 hopanol

C32 hopanol

Cholestan-3β-olCholesta-524-dien-3β-ol

Cholest-7-en-3β-ol

4-Methyl-cholesta-8(14)24-dien-3β-ol

4-Methyl-cholest-7-en-3β-ol

4-Methyl-cholesta-724-dien-3β-ol

Cholestan-3β-ol

Cholesta-524-dien-3β-ol

Cholest-7-en-3β-ol

4-Methyl-cholesta-dien-3β-ol

4-Methyl-cholesta-8(14)24-dien-3β-ol

4-Methyl-cholest-7-en-3β-ol

4-Methyl-cholesta-724-dien-3β-ol

4414-Trimethyl-cholesta-8(9)24-dien-3β-ol

4414-Trimethyl-cholesta-8(9)24-dien-3β-ol

1950

1520

135

150

130

106

52

24

ND

ND

ND

31

47

18

4

8

5

1

1

1

lt1

lt1

-710

-710

-737

-726

-751

-733

-717

NA

NA

NA

NA

NA

NA

NA

NA

-729

Gill tissueTotal concn δ13C(microg g-1)b (o)c

3460

222090

387

166

11

381

83

45

73

132

68

ND

ND

6

5

5

46

2

1040

828

212

-709

-728

-698

-728

-673

-742

-716-774

-754

-707

-685

NA

NA

NA

NA

-749

NAd

Mantle tissueTotal concn δ13C(microg g-1)b (o)c

-722

-715

-726

-695

NA

NA

NA

NA

NA

NA

NA

NA

NA

NA

-723

2750

2130

228124

132

NAd

53

57

25

ND

ND

ND

14

12

4

4

6

2

4

3

82

61

Tissue Distribution and δ13C Values for Seep Mussel Cyclic Triterpenoids

ldquoSterols and hopanols are listed in relative in order of elution from DB-5 columns and were ideatified bt a combination of TLC mobility on conventionaland silver-impregated plates relative retention times on DB-5 columns and the mass spectra of trimethylsilyl and acetate derivatives Trace amounts of cholest8(9)-en-3βminusol and a44-dimethyl monene were also detected in gill tissueThe 4-methyl-cholesta-724-dien-3β-ol may have an internal double bondat either C-7(8) or C-8(9) The C31 and C32 hopanols are products of cleavage of the polyhydroxylated side chains of the various BHP molecules (Fig 1) (45)

b Total amount of material recovered per gram (dry weight) based on the results of an analysis of isolated tissues obtained from a singal dissected mussel c δ13C values were determined by performing a compound-specific analysis for the acetate derivatives of individual hopanol and sterol compounds that werelarge enough to analyze The reporied δ13C values for the free hydroxyl and were calculated after we determined ampirically the isotope effect due to acetatederivative formationb NA not analyzedc NA compound not detected

- - -

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Image by MIT OpenCourseWare

35

Lanostane (XVIII δδ13C -70permil)hop-17-(21)-ene XII δ13C -32permil)

Norlanostane (XVII δδ13C -80permil)

Courtesy Elsevier Inc httpwwwsciencedirectcom Used with permission

36

35

Lanostane (XVIII δδ13C -70permil)hop-17-(21)-ene XII δ13C -32permil)

Norlanostane (XVII δδ13C -80permil)

Courtesy Elsevier Inc httpwwwsciencedirectcom Used with permission

36

Lanostane (XVIII δδ13C -70permil)hop-17-(21)-ene XII δ13C -32permil)

Norlanostane (XVII δδ13C -80permil)

Courtesy Elsevier Inc httpwwwsciencedirectcom Used with permission

36

C-isotopic Composition of Organic Compounds

bull Fractionation during biosynthesis (lipids)

37

C-isotopic compositions of amino acids from Anabeanea grown on different N-sources (Macko et al 1987)

This image has been removed due to copyright restrictions

38

39

20

10

1214

1618

0246

8

asx glx phe ala glyser thr arg ile tyr leu

Amino Acid

Abelson and Hoering 1961

Image by MIT OpenCourseWare

Intramolecular C-isotopic Differences (DeNiro and Epstein 1977 Monson and Hayes 1980

1982 reviewed Hayes 2001)

Reactions occur between molecules but isotope selectivity is expressed as chemical bonds that are made or broken at particular carbon positions

Isotope effects pertain to those specific positions and control fractionations only at that reaction site not throughout the whole molecule

To calculate changes in the isotopic compositions of whole molecules we must first calculate the change at the site and then allow for the rest of the molecule because the isotopic shift is diluted by mixing with carbon that is just along for the ridehelliphelliphelliphelliphelliphellipHayes 2002

40

NAD+ NADH + H+

Isotopic Fractionations in Biosynthetic Reactions

3 2 1 3 2 1 H3C-C-CO2H H3C-C-SCoA + CO2

CoASHO O Pyruvate Dehydrogenase

(12K13K)C-2 = 10232

The species containing carbon-12 at position 2 reacts 10232 times more rapidly that the species containing carbon-13 at that position

It is termed ldquoa 23permil isotope effectrdquo

41

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

C-isotopic compositions of amino acids from Anabeanea grown on different N-sources (Macko et al 1987)

This image has been removed due to copyright restrictions

38

39

20

10

1214

1618

0246

8

asx glx phe ala glyser thr arg ile tyr leu

Amino Acid

Abelson and Hoering 1961

Image by MIT OpenCourseWare

Intramolecular C-isotopic Differences (DeNiro and Epstein 1977 Monson and Hayes 1980

1982 reviewed Hayes 2001)

Reactions occur between molecules but isotope selectivity is expressed as chemical bonds that are made or broken at particular carbon positions

Isotope effects pertain to those specific positions and control fractionations only at that reaction site not throughout the whole molecule

To calculate changes in the isotopic compositions of whole molecules we must first calculate the change at the site and then allow for the rest of the molecule because the isotopic shift is diluted by mixing with carbon that is just along for the ridehelliphelliphelliphelliphelliphellipHayes 2002

40

NAD+ NADH + H+

Isotopic Fractionations in Biosynthetic Reactions

3 2 1 3 2 1 H3C-C-CO2H H3C-C-SCoA + CO2

CoASHO O Pyruvate Dehydrogenase

(12K13K)C-2 = 10232

The species containing carbon-12 at position 2 reacts 10232 times more rapidly that the species containing carbon-13 at that position

It is termed ldquoa 23permil isotope effectrdquo

41

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

39

20

10

1214

1618

0246

8

asx glx phe ala glyser thr arg ile tyr leu

Amino Acid

Abelson and Hoering 1961

Image by MIT OpenCourseWare

Intramolecular C-isotopic Differences (DeNiro and Epstein 1977 Monson and Hayes 1980

1982 reviewed Hayes 2001)

Reactions occur between molecules but isotope selectivity is expressed as chemical bonds that are made or broken at particular carbon positions

Isotope effects pertain to those specific positions and control fractionations only at that reaction site not throughout the whole molecule

To calculate changes in the isotopic compositions of whole molecules we must first calculate the change at the site and then allow for the rest of the molecule because the isotopic shift is diluted by mixing with carbon that is just along for the ridehelliphelliphelliphelliphelliphellipHayes 2002

40

NAD+ NADH + H+

Isotopic Fractionations in Biosynthetic Reactions

3 2 1 3 2 1 H3C-C-CO2H H3C-C-SCoA + CO2

CoASHO O Pyruvate Dehydrogenase

(12K13K)C-2 = 10232

The species containing carbon-12 at position 2 reacts 10232 times more rapidly that the species containing carbon-13 at that position

It is termed ldquoa 23permil isotope effectrdquo

41

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

Intramolecular C-isotopic Differences (DeNiro and Epstein 1977 Monson and Hayes 1980

1982 reviewed Hayes 2001)

Reactions occur between molecules but isotope selectivity is expressed as chemical bonds that are made or broken at particular carbon positions

Isotope effects pertain to those specific positions and control fractionations only at that reaction site not throughout the whole molecule

To calculate changes in the isotopic compositions of whole molecules we must first calculate the change at the site and then allow for the rest of the molecule because the isotopic shift is diluted by mixing with carbon that is just along for the ridehelliphelliphelliphelliphelliphellipHayes 2002

40

NAD+ NADH + H+

Isotopic Fractionations in Biosynthetic Reactions

3 2 1 3 2 1 H3C-C-CO2H H3C-C-SCoA + CO2

CoASHO O Pyruvate Dehydrogenase

(12K13K)C-2 = 10232

The species containing carbon-12 at position 2 reacts 10232 times more rapidly that the species containing carbon-13 at that position

It is termed ldquoa 23permil isotope effectrdquo

41

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

NAD+ NADH + H+

Isotopic Fractionations in Biosynthetic Reactions

3 2 1 3 2 1 H3C-C-CO2H H3C-C-SCoA + CO2

CoASHO O Pyruvate Dehydrogenase

(12K13K)C-2 = 10232

The species containing carbon-12 at position 2 reacts 10232 times more rapidly that the species containing carbon-13 at that position

It is termed ldquoa 23permil isotope effectrdquo

41

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

These images have been removed due to copyright restrictions

Flows of C at the pyruvate branch point in the metabolism of E coli grown aerobically on glucose (Roberts 1955) 74 of the pyruvate is decarboxylated to yield Ac-CoA The observed depletion at odd-numbered positions of FAcids is shown at the right indicating that the isotope effect at C-2 in the pyruvate dehydrogenase reaction is 23permil

42

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

DH by GCndashpyrolysisndashIRMS

Hilkert 1998 Burgoyne 1998 Sessions 1999

43

Gas Chromatograph Isotope RatioMass Spectrometer

EnergyFilter

Pyrolysis Interface(1440 C)ο

H2H-D

H-H

Image by MIT OpenCourseWare

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms

MIT OpenCourseWarehttpocwmitedu

12007 GeologySpring 2013 For information about citing these materials or our Terms of Use visit httpocwmiteduterms