Mixed-add fermentation

Products of the Mixed Add Fermentation by E, coli at Low and High Values of pH. Table 17-2 "Activated" Groups Used in Biosynthesis. Table 17-3 Some Effects of Insulin on Enzymes... 

Mixed add Fermentation of sugars Escherichia Erwinia Shigella Salmonella Proteus Yersinia Enterobacteriaceae... 

Put the grains in about 6 quarts of water and heat to near simmering. Remove grains from water before allowing to boil. Add extract and hops to kettle and boil 60 minutes. Add 3 gallons of cold water to primary fermenter. Remove wort from heat and add to primary fermenter. Add raspberries and mix. Pitch yeast and mix again. Ferment about 4 days, then rack to a secondary fermenter. Bottle after about 10 days, priming with % cup malt extract. 

Production of 2,3-BD is via a mixed acid fermentation pathway that also leads to a mix of acetate, lactate, formate, succinate, and ethanol. Juni and Heym (1956) proposed that 2,3-BD is produced in bacteria from pyruvate through the intermediates a-acetolactate and acetoin. Also, microorganisms can degrade 2,3-BD (i.e., it is biodegradable), a feature that may add to its attractiveness as an industrial chemical. 

Its most common adulterations consist of dilution and removal oj cream. It may also be mixed with various extraneous substances (occasionally flour, starch, dextrin, albumin, etc.) or treated with antiseptics (boric acid, borax, salicylic acid, formaldehyde, benzoic add, fluorides, hydrogen peroxide, etc.) to make it keep, or with alkaline salts (sodium carbonate or bicarbonate) to hinder or correct for fermentation. Analysis of milk includes, therefore, the following determinations ... 

Mechanically stirred hybrid airlift reactors (see Fig. 6) are well suited for use with shear sensitive fermentations that require better oxygen transfer and mixing than is provided by a conventional airlift reactor. Use of a low-power axial flow impeller in the downcomer of an airlift bioreactor can substantially enhance liquid circulation rates, mixing, and gas-liquid mass transfer relative to operation without the agitator. This enhancement increases power consumption disproportionately and also adds other disadvantages of a mechanical agitation system. 

Mix all the above together in a container. Attach an airlock and let ferment for 2 weeks or until fermentation stops. Add additional honey to taste and store all in refrigerator. 

If lactose-fermenting P. shermanii is used, cheese whey can be used as a substrate. From the whey containing 12% of dry substances, only 50% of lactose is utilized by P. shermanii, producing 1.6-2.2% solution of propionic acid (Bodie et al., 1987). In the combined batch culture, composed of P. shermanii and Lactobacillus casei, lactose is completely utilized and a 3% solution of propionic acid is produced in 52 h. When the medium is partially replaced during cultivation, a 4.5% solution of propionic acid is obtained by raising the concentration of dry substances in the whey up to 18% the production is increased up to 6.5% in mixed culture. For industrial production it is advisable to add a reducing agent to the medium (see above. Chapter 3), then the ratio of propionic to acetic acid will be increased (Emde and Schink, 1990). 

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