BSC 260
Industrial microbiology
5/4/12
Industrial microbiology-the use of microbes to synthesize desired product
Fungi or Streptomyces most common organisms used
Genetically engineered bacteria are becoming more common
Useful industrial microorganism
Easy to inoculate
Requires minimal media to grow
Fast growth
Good expression of product
Not pathogenic
Products-
Primary metabolites are produced when microbe is growing rapidly
Typically smaller molecules
Secondary metabolites are produced during lag phase or stress
Typically more complex molecules
Culture is grown in fermentor that maintains optimal conditions
Can be a few liters or several hundred thousand liters in size
Antibiotics are most important product
Most are secondary metabolites
Test for production of antibiotics with a few known bacteria
See if there is zone of clearance around colony of test microbe
Majority of microbes produce antibiotics, however, only a small number are safe and effective for use
Takes 15 years and $1 billion to get an antibiotic to market
Vitamins and supplements are next largest product
Utilize microbial pathways to produce nutrient
Purified and tested for purity and safety
Secreted enzymes are also important
Grow culture that secretes enzyme into media
Draw off media and purify desired product
Septic cleaner, food modifiers, biotech enzymes
Alcohol-first industrial microbiological product
Wine-Fermented fruit
Most comes from grapes
Red wine-red grapes with skin
White wine-white grapes or red grapes without skin
Skin has tannins that are astringent
Fruit is fermented, strained, then typically aged in barrels
Barrels also provide some character of wine
Terminology:
Dry means less sugar
Dry reds have more tannins
Dry whites are more acidic
Range from dry to sweet
Reds can be aged in barrels much longer than whites due to the tannins
Brewing
Beer is essentially four ingredients: grain, hops, water and yeast
Two different types of yeast strains
Top fermenters produce ales
Bottom fermenters produce lagers
Lambic brewing uses natural microbes in environment
Distilling
Fermentation of grains or fruit followed by purification of the alcohol
Use a still to remove alcohol from water and other molecules
All spirits start out as clear alcohol
Get color from barrel aging or adding other components
Example: bourbon is 51% corn by law
Aged in new, charred American oak barrels
Longer aging produces darker color
Biofuels-ethanol is biggest in US
We use corn starch however, research into other sources
In Brazil sugar cane is abundant, so ethanol is much cheaper
Expression of mammalian proteins by bacteria
Genetic engineering-need to modify DNA
Produce cDNA from mRNA
Clone into expression vector with strong promoter