Foundations in Microbiology

Lecture PowerPoint to accompany
Foundations in
Microbiology
Seventh Edition
Talaro
Chapter 27
Applied and Industrial
Microbiology
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
27.1 Applied Microbiology and
Biotechnology
• Applied microbiology – microbes are used to
treat wastewater and bioremediate damaged
environments
• Industrial microbiology – use of microbes in
making food, medical, manufacturing, and
agricultural products
• Biotechnology – uses microbes for practical
applications
• Fermentation – controlled culture of microbes to
produce desired organic compounds
2
Water and Wastewater Treatment
Water purification
• In most cities, water is treated in a stepwise process
before it is supplied to consumers
• Impoundment in large, protected reservoir – storage
and sedimentation; treated to prevent overgrowth of
cyanobacteria
• Pumped to holding tanks for further settling,
aeration, and filtration; chemical treatment with a
chlorine, ozone, or peroxide disinfectant
3
Figure 27.1
Major steps in water purification
4
Sewage treatment
• Sewage – used wastewater containing chemicals,
debris, and microorganisms
• Typically requires 3 phases:
– Primary phase – removes floating, bulky physical objects
– Secondary phase – removes the organic matter by
biodegradation, natural bioremediation in a large digester
forming sludge which is aerated by injection and stirred
– Tertiary phase – filtration, disinfection, and removal of
chemical pollutants
• Gradually released
• Anaerobic digesters: turn sludge into a secondary
source of energy
5
Figure 27.3 The primary, secondary,
and tertiary stages in sewage treatment
Insert figure 26.24
Sewage treatment
6
Figure 27.4 Treatment of
sewage and wastewater
7
27.2 Microorganisms and Food
• Microbes and humans compete for nutrients
in food
• The effects of microorganisms on food can
be
– Beneficial
– Detrimental
– Neutral
8
Microbial Fermentations in Food Products
Microbes, through fermentation, can impart desirable
aroma, flavor, or texture to foods (starter cultures)
• Bread – yeast leaven dough by giving off CO2
• Beer – fermentation of wort
• Wine – fermentation of fruit juices
• Vegetable products – sauerkraut, pickles
• Vinegar – fermentation of plant juices
• Milk and dairy products – cheeses, yogurt
9
Figure 27.5 Hops
10
Figure 27.7
Wine making
11
Figure 27.8
Microbes at work in milk products
12
Figure 27.9
Cheese making
13
Microorganisms as food
• Mass-produced yeasts, molds, algae, and
bacteria
• Single-celled protein and filamentous
mycoprotein added to animal feeds
14
Microbial Involvement in Food-Borne
Diseases
• Food poisoning – diseases caused by ingesting
food
• 2 types:
– Food intoxication – results from ingesting exotoxins
secreted from bacterial cells growing in food
– Food infection – ingestion of whole microbes that
target the intestine – salmonellosis, shigellosis
• Other common agents – Campylobacter,
Salmonella, Clostridium, Shigella, Staphylococcus
aureus
15
Figure 27.10
Food-borne
illnesses
Insert figure 26.31
Food-borne illnesses
16
17
Prevention Measures for Food
Poisoning and Spoilage
• Prevent incorporation of microbes into food
– Aseptic technique
– Handwashing and proper hygiene
• Prevent survival or multiplication of microbes in
food
–
–
–
–
–
–
Heat – autoclaving, pasteurization, cooking
Cold – refrigeration, freezing
Radiation – UV, ionizing
Chemical preservatives – NaCl, organic acids
Dessication
Spraying of bacteriophages
18
Figure 27.11
Preventing food
poisoning and
spoilage
19
Figure 27.12
Pasteurizer
Figure 27.13
Temperatures and microbial
growth
20
27.3 General Concepts in
Industrial Microbiology
• Bulk production of organic compounds such
as antibiotics, hormones, vitamins, acids,
solvents, and enzymes
• Many processes involving fermentation
21
22
23
• Mutant strains of bacteria and fungi that synthesize large
amounts of metabolic intermediates (metabolites)
• Primary metabolites – produced during major
metabolic pathways and are essential to microbe’s
function
– Amino acids, organic acids synthesized during logarithmic
growth
• Secondary metabolites – by-products of metabolism
that may not be critical to microbe’s function
– Vitamins, antibiotics, and steroids synthesized during
stationary phase
24
Figure 27.14 Primary and secondary microbial
metabolites harvested by industrial processes
25
Tricks to Increase the Amount of Chosen
End Product
1. Manipulate growth environment to
increase synthesis of metabolite
2. Select strains that genetically lack a
feedback system
3. Many syntheses occur in sequential
fashion involving more than one organism
– Biotransformation – waste product of one
organism becomes the building block of the
next
26
Figure 27.15
Example of biotransformation
27
From Microbial Factories to
Industrial Factories
• Produce appropriate levels of growth and
fermentation in a carefully controlled
environment
• Commercial fermentation carried out in
fermentors – a device in which mass
cultures are grown, reactions take place, and
product develops
28
Figure 27.17
29
Substance Production
•
Steps in mass production:
1. Introduction of microbes and sterile media into
reaction chamber
2. Fermentation
3. Downstream processing (recovery, purification,
packaging)
4. Removal of waste
•
Carried out aseptically and monitored for rate
of flow and quality of product
30
Figure 27.18
Layout for a
fermentation
plant
31
• Batch fermentations – substrate added to
system all at once and taken through a limited
run until product is harvested
• Continuous feed systems – nutrients are
continuously fed into the reactor and product
is siphoned off throughout run
32
• Pharmaceutical products
–
–
–
–
Antibiotics
Hormones
Vitamins
Vaccines
• Miscellaneous products
–
–
–
–
–
–
Biopesticides
Enzymes
Amino acids
Organic acids
Solvents
Natural flavor compounds
33