Microbiology Lecture 29 notes p.784-804 Microbial Biotechnology

Propionibacterium strains used to make Swiss cheese: innoc. wet leather in shoe for a few days.

Endless job security for makers of new strains with novel virus-resistance patterns

Traditional microbiology: many continuing opportunities. Lactic acid = excellent preservative for sauerkraut, silage, cucumbers, etc.

Cheese: generally innoculate with 3 strains; differing viral resistance patterns. Once a virus finds a factory, its target bacterium can never be used again in that facility.

Saccharomyces cerevisiae; the E. coli of single-celled eukaryotes. Yeast products at least as important as lactic acid bacteria (if not more important).

Pediococcus damnosis, Pediococcus perniciosis bad reputations for oxidizing ethanol to acetic acid (vinegar). Fungal strains improve and bacterium (Oenococcus oeni) converts malic acid to lactic (less acidic wine)

Yeast go after sugars, so, cleave starch from rice, cereal grains as described in text (amylases of malt, fungi used for beer, rice products).

Mixed cultures quite stable, useful, exclusive of contaminants. Japan, mixed-culture food industries = 20 X as important as industrial alcohol.

Microbial insecticides: Bacillus thuringiensis (Thiricide) by far most famous. Monsanto: Incide (Pseudomonas fluorescens, an endosymbiont) can carry numerous selectively toxic genes.

Text: Bt, Bp, N. locustae, baculoviruses...all ecologically safe...have no effect on plants or animals, including humans." Statement HOTLY contested in Europe. GMOs very controversial.

Malawi: only ground meal allowed. Zambian president: "...won't eat these poisons."

Problem: How do you prove a doomsday possibility won't happen? Ex. Prove glyphosate resistance will never get into weeds. Ice^- genes not transmissible to ragweed.

Much cheaper to dream up potential doomsday scenarios than prove they can't happen. Problem: "How to deal with Jeremy Rifkin."Microbes as chemical factories: Clostridium acetobutylicum of Chaim Weissman most famous, yet other valuable processes listed in text:

(anaerobic) "culture does not have to be aerated." Example: Con Agra's electric bill several years ago = $12000 per month for aeration in Russellville. Anaerobic digester produces methane; much less microbial mass.

Ethanol, acetone, butanol, antibiotics, amino acids, enzymes, steroids, hormones, cDNA (intronless), insulin, Ice^-bacteria, Lactobacillus plantarum strain with amylase (attach starch)