Alcohols biologically produced

Notice that the conversion of citrate to cis-aconitate is a biological example of the dehydration of an alcohol to produce an alkene (Section 13.5). The conversion of cis-aconitate to isocitrate is a biochemical example of the hydration of an alkene to produce an alcohol (Sections 12.5 and 13.5). 

Other Processes. Isopropyl alcohol can be prepared by the Hquid-phase oxidation of propane (118). It is produced iacidentaHy by the reductive condensation of acetone, and is pardy recovered from fermentation (119). Large-scale commercial biological production of isopropyl alcohol from carbohydrate raw materials has also been studied (120—123). 

In the early years of the chemical industry, use of biological agents centered on fermentation (qv) techniques for the production of food products, eg, vinegar (qv), cheeses (see Milk and milk products), beer (qv), and of simple organic compounds such as acetone (qv), ethanol (qv), and the butyl alcohols (qv). By the middle of the twentieth century, most simple organic chemicals were produced synthetically. Fermentation was used for food products and for more complex substances such as pharmaceuticals (qv) (see also Antibiotics). Moreover, supports were developed to immobilize enzymes for use in industrial processes such as the hydrolysis of starch (qv) (see Enzyme applications). 

Recovery of Riologieal Conversion Products Biological conversion produces that can be derived from solid wastes include compost, methane, various proteins and alcohols, and a variety of other intermediate organic compounds. The principal processes that have been used are reported in Table 25-64. Composting and anaerobic digestion, the two most highly developed processes, are considered further. The recovery of gas from landfills is discussed in the portion of this sec tion dealing with ultimate disposal. 

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