Microbial Biotechnology

1
Microbial Biotechnology

• Chapter 29

2
Industrial Microbiology

• Humans were using microbes even before they knew
  about their existence
• As the knowledge of microbes grew , humans
  improved expanded their uses
• Now managing these microbe has become a science

3
Uses of Microbes

• Antibiotics
• Vitamins
• Food supplements
• Industrial chemicals
• Recombinant DNA technology

4
Microbiotechnology

• Traditional uses? make preserve human animal
  food
• As chemical factories? make chemicals drugs
• Genetically engineered microbes

5
Traditional uses

• Lactic acid bacteria
• Ferment sugars,
• their metabolic products have a pleasant taste
• Used to make dairy products, cheese, sauerkraut,
  green olives silage
• With exception of some streptococci these
  organisms are harmless to humans

6
Traditional uses

• Yeasts (Saccharomyces cerevisiae)
• Are as important as lactic acid bacteria
• Ferment sugars produce ethanol CO2
• Used in the wine industry
• Bread making
• To make vinegar ? 2 step process- Yeasts ferment
  sugar to ethanol, then Acetobacter converts that
  to acetic acid

7
Mixed cultures

• Cultures of bacteria fungi
• Used to make fermented foods? kefir, soy sauce,
  miso

8
Microbial Insecticides

• Unlike chemical insecticides these are
  ecologically safe
• Species of Bacillus are insect pathogens
• B. thuringiensis ? endospores lethal to insects (
  marketed as Bt)
• B. popilliae? controls japanese beetles (marketed
  as Bp)
• Protozoa? Nosema locustae? bait for grasshoppers
  locusts

9
2 Chemical Factories

• Due to their rapid rate of growth and metabolism
  microbes are use to manufacture many commercial
  products
• Can be done
• Anaerobically
• Aerobically

10
Anaerobic Fermentations

• Most common substrate used is blackstrap molasses
• Ethanol
• Acetone
• Butanol

11
Aerobic Processes

• Sterilized air must be supplied to prevent
  contamination of cultures
• Antibiotics
• Amino acids? used to enhance flavor of foods
• Enzymes? wide variety of uses

12
Genetically Engineered Microbes

• Medical Uses
• Agricultural Uses

13
Medical Uses

• Genetically engineered microbes use for
• Hormones
• Human growth hormone
• Insulin
• Tissue plasminogen activator? binds to
  dissolves clots
• Vitamins

14
Agricultural Uses

• Bt toxin
• Ice minus gene
• Better silage makers