Industrial Microbiology

Midterm 2

Yogurt Fermentation

Pasteurized milk is innoculated by streprococcus thermophilus, and lactobacillus bulgarious and incubated. S. Thermophilus produces lactic acid, L. bulgaricus contributes lactic acid and aromatics that give the product a distinct taste.

Cheese Fermentation

Coagulation of milk to curd, separation of curd from whey, shaping the curd, ripening to achieve flavour and texture

Cheese Coagulation

Adjusts the pH until the casein precipitates, or by adding milk-clotting enzymes such as rennin (chymosin) which curdles milk.

Rennin

Originally obtained from calves stomachs, now bionengineered by recombinant E.Coli

Bread Fermentation

As yeast ferments, it converts sugar to ethanol and CO2, escaping gas is trapped in wheat gluten results in expansion “rising” CO2 and ethanol eliminated during baking.

Alcoholic Beverages

Produces from fermentation of fruit sugars or grain sugars, yeasts of the genus saccharomyces are widely used.

Wine

Grapes contain natural yeasts, crushing grapes naturally starts fermentation but must be treated with sulfur dioxide or pasturized to kill the natural microbiota then inoculated with proprietary strain of saccharomyces.

Biofuels

ethanol replaces fossil fuels, starch produces ethanol and energy stream is needed to breakdown starch for enzymatic attack and to distill the ethanol

Generation of Biofuels

Food crops, organic waste, algae-based fuels, genetically modified microorganisms

Streptomyces

A prolific antibiotic producer

Antibiotic Discovery

produced mainly by fungi and bacteria, anti-b producing organisms have genes that render them resistant to the anti-b they produce

Antibiotic Production Assay

Agar overlay method, minimal medium, starvation conditions

Pantoea Ananatis BRT175

Produces PNP-1, strawberry leaf isolate, produces antibiotic against fire blight pathogen erwinia

Mutagenesis

A process to identify biosynthetic genes,

1) create random mutants of the antibiotic producing microbe using transposon

2) assay every mutant individually until you find those that no longer produce the antibiotic

3) identify the gene that has been mutates as it is involved in antibiotic production

PNP-1 Biosynthetic Cluster

All mutations identified were within the same region which contained 7 genes in a cluster which is similar to the FVG gene cluster found in other bacteria

P. agglomerans Tx10

Produces PNP-2, gene cluster identified, mutant no longer can produce PNP-2, when wild type and mutant Tx10 are plated on a different species, both produce a antibiotic

Acinetobacter Baumannii and Pseudomonas Aeruginosa

opportunistic human pathogens, problem for immunocompromised individuals and soldiers, multi drug resistant so limited treatment options. Inhibited by P. Agglomerans 3581r and P.Agglomerans SN01080r, antibiotic called PNP-3

PNP-3 Expressed in Erwinia

4 biosynthetic genes cloned, when expressed as Erwinia the bacteria die, when antibiotic transporter is expressed then antibiotic is exported

P. Agglomerans 20kB447973

5000 mutants screened in 35 minutes, 13 antibiotic mutants recovered, and inhibits RNA synthesis

Botulinum Toxin Type A

Botox, neurotoxin produced by bacterium clostridium botulinum. Temporarily reduces wrinkles by relaxing facial muscles lasting 3-4 months

Botulism

At high doses, Botox become a life threatening illness causing muscle weakness, paralysis, and respiratory muscle paralysis.

How Botox works

Neurons signals reach end of neurons, n. transmitters fuse with cell membrane, releasing n. transmitter. They cross the synapse and bind to receptors on next cell. Botox cleaves proteins that prevent vesicles from fusing with plasma membrane and releasing acetylcholine.

Biosurfactants

Surface-active compounds produced by bacteria and fungi that reduce surface tension, emulsify oil and water allowing bacteria to move along surfaces.

Biosurfactant Potential Applications

Oil spill cleanup, bioremediation, detergents, agriculture, food industry

Dictyostelium Discoideum

single celled amoeba, when food becomes scarce releases chemical signals that aggregate into multicellular mass that form migrating slug developing a fruiting body, producing spores that disperse and germinate into new amoebae

Grazing Resistance Model System

Bacterial Anti-predation strategies may be useful for evading host immune responses, correlated with pathogenicity in various microbial systems

rhl genes for Grazing Resistance

knocking out rhl genes impacts swarming ability and allows amoebae to graze and form spores

Ananatoside

Cytotoxic, wild type reduces cell viability significantly while mutant does not reduces cell viability

Pseudomonas Syringae

bacterium that produces ice-nucleating proteins on its outer membrane that promote ice formation by organizing water molecules into ice crystals at higher temperatures

Microbial Fuel Cells

harness metabolism to make electrical energy by breaking down organic compounds at the anode to release electrical current, electrons move through an external circuit to the cathode generating an electrical current, protons move through an electrolyte/membrane toward cathode where they combine with electrons and oxygen to form water.