(Micro Bio) Microbial Nutrition

8/3/2019 (Micro Bio) Microbial Nutrition

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MICROBIALNUTRITION AND

GROWTHI reserve all apologies for all copyright material used here. These are mostly

3rdhand materials from the web. This presentation is purely for educationalpurposes. If you believe that your copyright material is not geared to educate,

please inform me ([email protected]). I will always respect your

beliefs. *Please note that I disabled all animations to prevent issues after downloading*


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MICROBIAL NUTRITION

by_bryanyves


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Biochemical Components of Cells

Water: 80 % of TOTAL BIOMASS

Dry weight

Protein 40-70 %

Nucleic acid 13-34%

Lipid 10-15 %

Also monomers, intermediates and

inorganic ions

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Macronutrients

These are used to synthesize biomolecules (C, O,H, N, S, P) and to regulate many important

metabolic and structural functions (K+, Ca2+, Mg2+,

Fe2+)

proteins, carbohydrates, lipids and nucleic acids are

primarily made up of (COHNSP)

ions have variable roles (eg. K+ is needed to activate

enzymes during photosynthesis; Ca2+ is responsible for the

heat resistance of bacterial endospores; Mg2+ is a cofactor

for many enzymes; Fe2+/3+ is an important component of

electron transport systems)

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Micronutrients

These are needed in trace quantities that even very

slight contaminants in aqueous environments are

enough to meet the demands of microbes.

Trace elements include Ni, Mo, Co, Cu, Mn, and ZnGrowth factors such as vitamins and some enzymes are

also essential but are needed only in trace quantities.


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NUTRITIONAL TYPES

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NUTRIENT UPTAKE

Passive Transport does not require energy; substancesexist in a gradient and move from areas of higherconcentration towards areas of lower concentration diffusion osmosis (diffusion of water) facilitated diffusion (permeases)

Active Transport requires energy and carrier proteins;gradient independent

active transport (symport, antiport) group translocation (transported molecule chemically

altered) bulk transport (endocytosis, exocytosis, pinocytosis)

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DIFF

U

SIONACRO

SSAM

E MBR

AN

E

PASSIVE

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TONICITY

PASSIVE


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FACILITATED DIFFUSION

-utilizes channel and carrierproteins collectively called as

permeases

PASSIVE

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A

CTIVETRA

NSPORT

INPROCARYOTES

ACTIVE


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ACTIVE TRANSPORT USUALLY UTILIZES

TRANSPORT PROTEINS

ACTIVE

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Group Translocation

5 proteins involved.

transported substance (glucose) is chemically

altered (glucose-6-P) during transportation

ACTIVE

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ACTIVE


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Group Translocation

ACTIVE


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SIDEROPHORES

ACTIVE


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ENDOCYTOSIS

ACTIVE


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MICROBIAL

GROWTH

Microbes especially bacteria

divide asexually via binary

fission.

Generation Time

- the time required for parent

cell to form two new daughter

cells.

Microbial growth is always

measured by number, not by

biomass.

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MICROBIAL GROWTH CURVE

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Nf= Final population

Ni = Initial population

2n

= # cells in generation

n= generation number

Nf = (Ni)2n

Calculating Growth of Cells

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Doubling times for some common bacteria

under optimal conditions of growth

Bacterium Medium Generation Time(minutes)

Escherichia coli Glucose-salts 17

Bacillus megaterium Sucrose-salts 25

Streptococcus lactis Milk 26

Streptococcus lactis Lactose broth 48

Staphylococcusaureus

Heart infusion broth 27-30

Lactobacillusacidophilus

Milk 66-87

Rhizobium japonicum Mannitol-salts-yeastextract

344-461 (6hr)

Mycobacteriumtuberculosis

Synthetic 792-932 (15hr)

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Measuring Growth: Direct Count, Serial

Dilutions, Plate Counts and Turbidity


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A. Direct Count


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Spread-plate method Pour-plate method Pour-plate method with serial

dilution

B. Viable Count

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C. Indirect Count: Turbidity Measurement


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Calculation of the Number of Bacteria per milliliter of

Culture Using Serial Dilution


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Pour plate:

made by first

adding 1.0ml ofdiluted culture to

9ml of molten

agar

Spread plate:

made by adding

0.1ml of diluted

culture to surfaceof solid medium


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Co

lonyC

ounter


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Plate as viewedunder the colony

counter grid.

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Countable number of colonies

(30 to 300 per plate)

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The Petroff-Hausser Counting Chamber


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Turbidity, or a cloudy

appearance, is an

indicator of bacterialgrowth in urine in the

tube on the left

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A Spectrophotometer: This instrument can be used to

measure bacterial growth by determining the degree of

light transmission through the culture


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STREAK

PLATETECHNIQUE

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A Streak Plate

ofSerratiamarcescens.

Note the greatly

reduced

numbers ofgrowth

/colonies in

each

successive

region.


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Types of Culture Media

Natural Media: In nature, many species ofmicroorganisms grow together in oceans, lakes, and

soil and on living or dead organic matter

Synthetic medium (Defined): A medium prepared in thelaboratory from material of precise or reasonably well-

defined composition

Complex medium (Undefined): contains reasonablyfamiliar material but varies slightly in chemical

composition from batch to batch (e.g. peptone, a

product of enzyme digestion of proteins)

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Selective, Differential, and

Enrichment Media

Selective Medium: encourages growth of someorganisms but suppresses growth of others

(e.g. antibiotics)

Differential Medium: contains a constituent thatcauses an observable change that can differentiate

one population from the other (e.g. MacConkey agar)

Enrichment Medium: contains special nutrients thatallow growth of a particular organism that might nototherwise be present in sufficient numbers to allow it

to be isolated and identified

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Bristol's Medium for Algae(mg/liter)

NaNO3

250 mg

K2HPO

475 mg

KH2PO

4175 mg

CaCl2 25 mgNaCl 25 mg

MgSO4.7H

2O 75 mg

FeCl3

0.3 mg

MnSO4.

4H2O 0.3 mg

ZnSO4.7H

2O 0.2 mg

H3BO

30.2mg

CuSO4.5H

2O 0.06 mg

DEFINED MEDIA

-all components are known

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COMPLEX MEDIA - components are unknownOfCas

einNutri

PepAcid

Hydrolyzate

Peptone/Tryptone/Yeast Extract

Bacteriological Media Ingredients

ANIMAL BASED & ANIMAL FREE VEGETABLE

PEPTONES:- Wide gamut of peptones for cell

nutrition, fermentation and media ingredients.

Peptones are low-cost growth promoting nutrients

used extensively as Dehydrated Culture media

ingredients,fermentation ingredients as animal cell

culture nutrients.

Animal Free Peptones

VegiPep S : Soy Peptone NON ANIMAL,NON GMO

VegiPep G : Peanut Peptone NON ANIMAL,

NON GMO Animal Origin Peptones

NutriPep Bacto Peptone

Nutri Pep Casein Peptone

Nutri Pep Meat PeptoneNutriPep Proteose Peptone

NutriPep Pancreatic Digest Of Casein

Nutri Pep Acid Hydrolyzate of Casein

Nutri Pep Acid Hydrolyzate of Soy

NutriPep Tryptose Nutri Pep Tryptone.

NutriPep Meat Extract Powder

Nutri Pep Yeast Extract Powderby_bryanyves


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The detection ofSalmonella

species is often complicated by

the presence of background flora

and other Enterobacteriaceae on

an agar plate. The presence of theselective agent, Tergitol 4, in

XLT-4 Agar inhibits many

organisms that can be

problematic on other plating

media. In addition, biochemical

and pH changes within themedium allow Salmonella spp.

(black colonies) to be

differentiated from organisms,

such as E. coli(yellow colonies)

and Shigella spp. (red colonies).

XLT-4 Agar

SELECTIVE MEDIA favor growth of organism of interest


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Blood Agar is a bacterial differential medium that can

distinguish normal from pathogenic bacteria based on theinteraction of sheep's blood and bacterial hemolytic enzymes.

DIFFERENTIAL MEDIA show comparative changes

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denti fic

ati on

ofurina

rytractpa

thog

enswith

differ e

ntialme

d ia(CHROM

agar )

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FACTORS AFFECTING GROWTH

Temperature

pH

Oxygen

Pressure

Salinity

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Effects of Temperature on Growth

95oF77oF40oF

Most of our plates are incubated at 37oC(98.6oF).

Conversion C to F = 1.8xC + 32

http://www.sciencemadesimple.com/conversions.html

Image: Pearson Education Inc. (2004) publishing as Benjamin Cummingsby_bryanyves


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Categories of Microbes Based on Temperature Range

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Psychrophiles (< 20 oC)

A form of psychrophile named Strain34h,

stained fluorescent blue for better viewing.

Polar regions are the usual

habitat of psychrophiles.


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Mesophiles (15-45oC)

The habitats of these organisms include soil, the human body,animals, etc. The optimal temperature of many pathogenic

mesophiles is 37 C (98 F), the normal human body

temperature. Mesophilic organisms have important uses in

food preparation especially in cheese and yogurt making and

in beer and wine making.

E. coli

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Thermophiles (45-80oC)

Thermophiles produce some of the

bright colors of Grand Prismatic

Spring, Yellowstone National Park


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Hyperthermophiles (65-110oC)

EXTREMELY HOT!!!

MostlyArchaeans believed to

be the first microbes on

earth!!! by_bryanyves


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pH

and

Growth


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Meet the Microbe!

Vibrio cholerae (Cholerabacteria) will grow

outside the body at apH of 9.0.

Acidobacterium-abundant in soils

(pH 3-5)

These unknown bacteria

were taken from the film on

the surface of sulfuric acid.


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Obligate Aerobes need oxygen to stay alive

Obligate Anaerobes die in presence of oxygen

Facultative Anaerobes not strict anaerobes; optimum

growth in anaerobic conditions but can still grow in thepresence of oxygen

Microaerophillic Bacteria require oxygen levels lowerthat that found under normal atmospheric conditions; aerobic

but optimum growth is when oxygen is minimal

Aerotolerant Anaerobes - can tolerate a small amount ofoxygen by being able to detoxify the poisonous forms of

oxygen present

Oxygen Requirements

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1: Obligate aerobic bacteria gather at top of test tube to absorb maximal amount of O2.

2: Obligate anaerobic bacteria gather at bottom to avoid oxygen.3: Facultative bacteria gather mostly at the top, since aerobic respiration is beneficial;

but as lack of oxygen does not hurt them, they can be found all along the test tube.

4: Microaerophiles gather at upper part of test tube. They require O2, but at low

concentration.

5: Aerotolerant bacteria are not affected by oxygen, and they are evenly spread along

the test tube. by_bryanyves


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OsmoticPressure

Some bacteria can be plasmolyzed by high

concentrations of solutes, which results in

the formation of plasmolysis bays

throughout the length of the cell.

These bays result from the contraction of

the cytoplasmic membrane in response to

hyperosmotic shock.

Why can you keep honey on the cupboard

for months, even years, without it spoiling?

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Salinity


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Salinity

Seawater: 3% NaCl Nonhalophile: less than 1%

Halotolerant: less than 5% Halophile: 1 to 15 % Extreme halophile: more than 15%


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Pressure

Barophiles- organisms that grow

at elevated pressure(3-1000 x air

pressure). (Found inocean depths often

in thermal vents)

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THANKS!!!

(Micro Bio) Microbial Nutrition

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