Fermentation products, from sugars

Many other chemicals can be obtained from both yeast and bacteria fermentation of sugars and pulp mill effluents. Potential fermentation products from wood hydrolysates include acetone, organic acids (acetic, butyric, lactic), glycerol, butanediol, and others.42... 

The antibiotic thiolactomycin (43), a fermentation product from a Nocardia species containing an unusual thiolactone moiety was patented as antibiotic no. 2-200 and subsequently reported in the literature in 1982 [73,74]. It resembles a sugar-derived a,/3-unsaturated 4-thioglycono-1,4-lactone and was found to be a broad-spectmm antibiotic [75] by interference with the fatty acid metabolism of bacteria and also inhibited inducible /3-lactamases [76]. A de novo synthesis of the racemate was reported by a Du Pont group in 1984 [77]. Chambers and Thomas [78] reported the synthesis of the (55j-enantiomer in 1989 and concluded from its optical rotation that the natural product is the (5i )-enantiomer. 

Abstract Many types of fermentation feedstock have been studied for the production of polyhydroxyalkanoate (PHA). Several industrial-scale processes have been developed for PHA production from sugars. Sugars are attractive feedstock because of their abundant supply worldwide, market stability, and also because the metabolism of PHA from sugars is very well understood. Recently, plant oils have been gaining much interest as a potential feedstock for PHA production. Industrial-scale processes for the production of PHA from plant oils are currently being developed. This chapter looks at the challenges in using plant oils, especially pahn oil as feedstock for PHA production. 

Xanthan gum [11138-66-2] is an anionic heteropolysaccharide produced by several species of bacteria in the genus Aanthomonas A. campestris NRRL B-1459 produces the biopolymer with the most desirable physical properties and is used for commercial production of xanthan gum (see Gums). This strain was identified in the 1950s as part of a program to develop microbial polysaccharides derived from fermentations utilizing com sugar (333,334). The primary... 

In the acid hydrolysis process (79—81), wood is treated with concentrated or dilute acid solution to produce a lignin-rich residue and a Hquor containing sugars, organic acids, furfural, and other chemicals. The process is adaptable to all species and all forms of wood waste. The Hquor can be concentrated to a molasses for animal feed (82), used as a substrate for fermentation to ethanol or yeast (82), or dehydrated to furfural and levulinic acid (83—86). Attempts have been made to obtain marketable products from the lignin residue (87) rather than using it as a fuel, but currently only carbohydrate-derived products appear practical. 

Rum. Rum is a distikate from the fermented juice of sugar cane, sugar cane symp, molasses, sugar beets, or other by-products distiked at less than 190° proof in such a manner that it possesses the taste, aroma, and characteristics generaky attributed to mm. It is bottled at not less than 80° proof. 

The metabolic pathway for bacterial sugar fermentation proceeds through the Embden-Meyerhof-Paranas (EMP) pathway. The pathway involves many catalysed enzyme reactions which start with glucose, a six-carbon carbohydrate, and end with two moles of three carbon intermediates, pyruvate. The end pyruvate may go to lactate or be converted to acetyl CoA for the tricarboxylic acid (TCA) cycle. The fermentation pathways from pyruvate and the resulting end products are shown in Figures 9.7 and 9.8. 

The term dextran has been applied to carbohydrate slimes originating from sugar sirups, fermenting vegetables and dairy products. 

The refractive index also varies with the amount of substance in a mixture. Most often, refractive index is used to assess the concentration of sugar in wine, soft drinks, cough medicines and other preparations having relatively high concentrations of sucrose. Refractive index is also used to determine the concentration of alcohol in fermented products. For sucrose solutions the refractive index varies from 1.3330 (pure water) to 1.5033 when the solution contains 85% sucrose. This is an increase of approximately 0.0002 in the refractive index for each 0.1%... 

It may be estimated that ethanol yields from lignocellulosics will range between 0.12 and 0.32 L kg-1 undried feedstock, depending upon the efficiency of five-carbon sugar conversion [26]. Other types of fermentation, including bacterial fermentation under aerobic and anaerobic conditions, can produce various other products from the sugar stream, including lactic acid. 

Hydrogen production from the bacterial fermentation of sugars has been examined in a variety of reactor systems. Hexose concentration has a greater effect on Hj yields than the HRT. Flocculation also was an important factor in the performance of the reactor (Van Ginkel and Logan, 2005). 

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