Industrial Microbiology and Biotechnology

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Dec 5, 2012 (5 years and 1 month ago)

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Chapter 27

Industrial Microbiology and
Biotechnology

27.1 Microorganisms in Industry


Microorganisms produce many useful organic
compounds.


Primary metabolites are directly involved in
normal growth, development,


and reproduction.


Secondary


metabolites have


important


ecological


functions and are


often species specific.

FIGURE 02: The products of fermentation


Many secondary metabolites have value as food
additives, pharmaceuticals, vitamins, etc.

FIGURE 27.3: The
chemistry of citrate
production


Microorganisms also
produce important
enzymes and other
products.


Some enzymes are
important commercially,
such as


amylase


pectinase


several proteases

Figure 01A: The Industrial
Fermentation Process.


Streptokinase breaks
down blood clots formed
during a heart attack.



Hyaluronidase facilitates
absorption of fluids
injected under the skin.



Lactones produced by
species of fungi are
used for flavor and
aroma enhancement.


Figure 01B: A pharmaceutical
technician monitors a series of
fermentors.

© Maximilian Stock LTD/Phototake/Alamy Images

27.2 Alcoholic Beverages


Beer is produced by
the fermentation of
malted barley by
species of the yeast
Saccharomyces.

FIGURE 04: A generalized process
for producing beer


Wine is produced by the fermentation of fruit
or plant extracts.


Fruit or plant materials are crushed to
produce juice.


Yeasts are added to begin fermentation in
anaerobic conditions.


The wine is aged in wooden


casks, where unique flavor


and aromas develop based


on:


yeast


cask wood


organic compounds in the


fruit/plant

FIGURE 05c Wooden casks

© LiquidLibrary


The mold
Botrytis cinerea

is used to enhance sugar
content in grapes for
sweet wines.



Distilled spirits contain
more alcohol than beer or
wine.


Ethyl alcohol results
from distillation of
fermented fruits or
grains.

Figure 05A: Stemmer
-
crusher

Courtesy of Jeffrey Pommerville

Figure 05B: Fermentation tanks

27.3 Other Microbial Products


Many antibiotics are the
result of industrial
production.


Penicillin was the first
antibiotic to be produced
on an industrial scale.


Antibiotic production can
involve fermentation,
producing natural
antibiotics or
semisynthetic drugs.

FIGURE 06b:
A false color
SEM of
S.
griseus
,
showing the
chains of cells

© Scimat/Photo Researchers, Inc.

Figure 06A:
Colonies of
S.
griseus

© Christine Case/Visuals Unlimited


Some microbial products can be used to control
insects.


A microbial toxin insecticide should be quick and
specific to an insect pest.

FIGURE 07a: A false color TEM of
Bacillus thuringiensis
, showing the
development of a spore (orange)

© George Chapman/Visuals Unlimited


Bacillus thuringiensis

produce a toxin (Bt
-
toxin)
during sporulation that is deposited on leaves.


If ingested by caterpillars, the toxin lyses the gut wall
causing paralysis and bacterial invasion.


It seems to be harmless to plants and humans.


Through biotechnology

cotton and corn plants


carrying the Bt
-
toxin


gene have been


developed that kill only

insects that eat them.


© Holt Studios International Ltd/Alamy Images

FIGURE 07b: Dead caterpillar on a leaf
treated with Bt
-
toxin


Bacillus sphaericus

kills two mosquito species if ingested.


Its genes were spliced into
Asticcacaulis excentris

to
enhance:


production


dissemination


the poison’s efficiency against other species



Photorhabdus luminescens

toxin, Pht, has a wider range
of activity than Bt.



Other sources of insecticidal activity include:


some viruses


a toxin in scorpion venom


spores of the fungus
Lagenidium giganteum
,

which

can kill mosquito larvae


Fungal organisms are also being commercially
developed.


Yeast cells are grown in fermentors.


They are sold as dry yeast or compressed yeast
cakes.


Many species of mushrooms are grown on farms.


High humidity and cool temperatures are required for
mushroom growth.

FIGURE 08b:

A mushroom farm

© Mashkov Yuri, Itar
-
Tass/Landov



Bioremediation helps
clean up pollution
naturally.



Naturally occurring
Pseudomonas
species
can be stimulated to
degrade oil in spills.



Species of
Arthrobacter

degrade oil and allow
plant growth in spill
regions.

Courtesy of the Exxon Valdez Oil Spill Trust Council/NOAA

FIGURE 09: The
Exxon Valdez

oil spill


Anaerobic and aerobic bacteria can reduce
polychlorinated biphenyls (PCBs) to:


carbon dioxide


water


hydrogen chloride



Bacteria can degrade trichloroethylene (TCE) in
contaminated ground water.



Deinococcus radiodurans
may be used to clean up:


radioactive waste


ionic mercury compounds



Bacteria can reduce levels of TNT in soil surrounding
weapons plants.


Industrial genetic engineering continues to make
advances.


Bacterial plasmids can be used to transfer a
foreign gene into a targeted bacterial cell.


Traits like antibiotic resistance and antibiotic
production can be transferred.

FIGURE 10: A TEM of

bacterial plasmids

© Dr. Gopal Murti/Visuals Unlimited


Scientists hope to insert genes from
Rhizobium

into
grain plants, removing the need for fertilizer.










Biotechnology may also be used to disrupt pathogen
life cycles to prevent disease.

FIGURE 11: Artist's
conception of a super
plant produced by
genetic engineering