Advancing a Biological Paradigm for Biomass Pretreatment

Tom Richard, Qin Chen, Deepti Tanjore, Farzaneh Rezaei

Wayne Curtis, Ming Tien, Dan CosgrovePenn State University

Haiyu Ren, Novozymes

Ken Moore, Iowa State University

Corey Radtke, Idaho National Laboratory

Kevin Shinners, University of Wisconsin

Feedstock storage challengesHarvested once a yearNeed long term storage of large quantitiesMinimize dry matter lossEliminate risk of fire

Storage

Pretreatment

Bioconversion

Sugar, ethanol, chemicals, and materials

Harvest

Most Biomass is Wet

Ensiled StorageAdvantages:• High moisture content• Low pH for long term storage• Synergies may allow less intensive pretreatment through

hydrolysis and saccharification Disadvantages:• Hydrolysis products (sugar) may degrade and be lost• Additional cost if cell wall degrading enzymes, microbes,

and/or chemicals are applied additives

Scaleable technology

Storage and pretreatment

Biomass FeedstockCell wall

degrading enzymes

Microbes

Fuel and Chemical Production

Alternative Strategies for Biocatalysis

Ensilaged storage and Pretreatment

Downstream Processing

Expansins

Methods

Flow chart

Corn Stover Harvest

Storage (-15 ºC)

Ensiled at 37 °C in Incubator

Weight pH DM Fiber Fraction

Data Analysis by Multiple Factors ANOVA

and MTB

Comparison & Conclusion

WSC

Kinetic Examination of Ensiled Stover at day 0, day 1, day 7 and day 21.

Silage without Enzyme or with Multifect A 40 (Genencor)

Glucose& xylose

a) Harvest Machineb) Harvested Fieldc) Food Vacuum sealerd) Incubatore) Fiber Analyzerf) Daisy II Incubatorg) HPLC

a b c

d e f

g

Screening Commercial Enzyme Products

1.39

0.28

2.38

2.14

0.02

0.36

0.08

C:H

TL 1.39

TL0.28

TR2.38

TR2.14

TR0.02

AN0.36

AN0.08

543 U/ml390 U/mlSafizym fl300

5144 U/g18624 U/gDyadic Xylanase 2XPTrichodermalongibrachiatum

278 U/ml116 U/mlMultifect CL

2607 U/g1219. U/gDeerlandCellulase TR

109 U/ml5712 U/mlMultifect xylanaseTrichoderma reesei

384 U/g1075 U/gDeerlandHemicellulase

1904 U/g24805. U/gEnzecoxylanase A Concertrate

Aspergillus niger

CellulaseHemicellulaseBrand nameMicroorganism source

0

1

2

3

4

5

6

7

8

9

10

0

0.33

1

3

7

14

21

0

0.33

1

3

7

14

21

0

0.33

1

3

7

14

21

0

0.33

1

3

7

14

21

Control TL1.39 TR2.14 TR2.37

Days

% DM

WSC

Butyric acid

Isobutyric acid

Propionic acid

Acetic acid

Lactic acid

Differential Products

Long-term Storage Effects

0.0

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

10.0

0 1 7 21 63 189 0 1 7 21 63 189Days

% D

M

WSC

Butyrate

Isobutyrate

Propionate

Acetate

Lactate

Enzyme ControlTR 2.37 Control

-4.0

-2.0

0.0

2.0

4.0

6.0

8.0

10.0

0 1 7 21 63 189 0 1 7 21 63 189

Days

Fibe

r deg

rada

tion

(% D

M c

hang

e) Hemicellulose

Cellulose

Fiber Degradation(concentration basis)

Control

TR 2.37 Control

Consolidated BioProcessing Resultsclostridium phytofermentens

0

10

20

30

40

50

K L+ M N+

mM

EthanolAcetateFormateLactate

S it h C St

Switchgrass Corn Stover

w/out ensiled w/out ensiled

Other biocatalyst strategies

• Lignin degrading enzymes

• Expansins

• Microbe-enzyme-substrate interactions

Issues and Concerns

• How can we best generate and identify synergies with downstream processing?

• What are the upstream opportunities and synergies with plant biotechnology?

• What are the critical tradeoffs between on-farm storage/pretreatment and more centralized strategies?

• Are the energetic and economic costs of biological pretreatment competitive?