Ch. 41: Biotechnology and Industrial Microbiology

microbes are the source of many products of industrial importance

• Industrial Products

• Agricultural Products

• Food Additives

• Medical Products

• Biofuels

abx

• Most are produced by Streptomyces spp. and filamentous fungi

• Penicillin and semisynthetic penicillin

biopolymers

• Used to modify flow characteristics of liquids and to serve as gelling agents

• Biosurfactants

  • important in bioremediation, oil spill dispersion, and enhancing oil recovery

reverse vaccinology

• mines the pathogen genome sequence

• “Good” antigen target:

  • expressed during infection

  • secreted on the surface

  • found in all strains

  • elicit a host immune response

  • essential for survival

biofuel production

• Population and economic growth increase energy demands

• Fossil fuels are finite resources

• The U.S. Department of Energy has set a goal of substituting 30% of gasoline with biofuels by 2030

• Ethanol and hydrogen gas

role of microorganisms in biofuel production

Certain microorganisms ferment sugars to produce ethanol, while others generate hydrogen gas through metabolic processes.

ethanol

• from degradation of plant starches in corn by amylases and amyloglucosidases → microbial fermentation

hydrogen gas

• a direct product of fermentation

• hydrogenase and nitrogenase enzymes

growing microbes in industrial settings

• Precise control of agitation, temperature, pH changes, and oxygenation

• Fermentation

  • scale-up

  • modifications of growth process 

  • stirred fermenters

• Continuous feed

  • continual addition of a critical nutrient 

  • prevents production and accumulation waste products

growing microbes - ideal conditions

• Knowing WHEN your microbe is producing WHAT you want is critical

• Primary metabolites

• secondary metabolites

primary metabolites

• produced during active growth of an organism

• essential for growth and reproduction

• ex: amino acids, nucleotides, fermentation end products, and enzymes

  • ethanol, organic acids

• Compounds related to microbial cells during exponential growth

• Use chemostats to improve rates in state of growth

secondary metabolites

• products of metabolism that accumulate following active growth

• usually synthesized when nutrients are limited or waste products accumulate after growth

  • not produced in chemostats

• serve ecological functions like defense or competition

• Mostly stationary phase

• part of a stress response

• ex: antibiotics

  • Penicillin

Biopesticides

Bacillus thuringiensis

• Parasporal body

  • produced during sporulation as an intracellular protein toxin crystal

  • microbial insecticide

• Insecticide (Bt)

  • Bt produces a toxin that specifically targets insect larvae without harming humans or beneficial organisms

  • used for over 40 years

  • does not accumulate in environment

microbes as products

• Common example is inoculation of legume seeds with rhizobia

• Nanotechnology

  • use of diatom 3-D structures as templates

  • use magnetosomes from magnetotactic bacteria to enhance contrast in magnetic resonance tomography (MRI) applications and as probes to detect cancer (binding to GM)

waste management

• Expensive

• Poor waste management is a significant contributor to environmental pollution

  • EPA says about 20% of global methane emission comes from landfills

• Microalgae for wastewater processing

  • Absorb and assimilate excess nitrogen and phosphorous

  • Biomass can be used to make feedstock or biofuel

• Genetically modified microorganisms