Fermentation of Enzymes

Carta, E. S. Soccol, C. R. Ramos, L. P. Fontana, J. D. Production of fumaric acid by fermentation of enzymic hydrolyzates derived from cassava bagasse, Bioresour. Technol, 1999, 68, 23-28. 

Today, the majority of enzymes used in the detergent industry are produced by cultivation of selected microorganisms in large submerse fermentation tanks. The production process and production strains have steadily been developed over the past 50 years and nowadays the fermentation of enzymes is based on the cutting-edge techniques within modem ceU biology. 

Biopolymer Extraction. Research interests involving new techniques for separation of biochemicals from fermentation broth and cell culture media have increased as biotechnology has grown. Most separation methods are limited to small-scale appHcations but recendy solvent extraction has been studied as a potential technique for continuous and large-scale production and the use of two-phase aqueous systems has received increasing attention (259). A range of enzymes have favorable partition properties in a system based on a PGE—dextran—salt solution (97) ... 

Alcoholic Fermentation. Certain types of starchy biomass such as com and high sugar crops are readily converted to ethanol under anaerobic fermentation conditions ia the presence of specific yeasts Saccharomyces cerevisia and other organisms (Fig. 6). However, alcohoHc fermentation of other types of biomass, such as wood and municipal wastes that contain high concentrations of cellulose, can be performed ia high yield only after the ceUulosics are converted to sugar concentrates by acid- or enzyme-catalyzed hydrolysis ... 

MacroHdes are obtained by controUed submerged aerobic fermentations of soil microorganisms. Although species of Streptomjces have dominated, species of Saccharopoljspora Micromonospora and Streptoverticillium are also weU represented. New techniques such as enzyme-linked immunosorbent assay (ELISA) based assays may prove beneficial for discovering new stmctures (464). 

More recently, interest has developed in the use of enzymes to catalyze the hydrolysis of cellulose to glucose (25—27). Domestic or forest product wastes can be used to produce the fermentation substrate. Whereas there has been much research on alcohol fermentation, whether from cereal grains, molasses, or wood hydrolysis, the commercial practice of this technology is primarily for the industrial alcohol and beverage alcohol industries. About 100 plants have been built for fuel ethanol from com, but only a few continue to operate (28). 

Coffee bioconversions through enzymatic hydrolysis have been used to modify green coffee and improve the finished product (60). Similarly, enzymes have been reported which increase yield and improve flavor of instant coffee (61). Fermentation of green coffee extracts to produce diacetyl [431 -03-8] a coffee flavor compound, has also been demonstrated (62). 

In 1878 the term enzyme, Greek for "in yeast," was proposed (8). It was reasoned that chemical compounds capable of catalysis, ie, ptyalin (amylase from sahva), pepsin, and others, should not be called ferments, as this term was already in use for yeast cells and other organisms. However, proof was not given for the actual existence of enzymes. EinaHy, in 1897, it was demonstrated that ceU-free yeast extract ("zymase") could convert glucose into ethanol and carbon dioxide in exactiy the same way as viable yeast cells. It took some time before these experiments and deductions were completely understood and accepted by the scientific community. 

In 1958, the microbial alkaline protease Alcalase (Novo Industries) was produced by fermentation of a strain of Bacillus licheniformis. It had high StabiHty and activity at pH 8—10, was marketed in 1961, and was incorporated into Bio 40. However, it was not until the successful marketing of the presoaking agent Biotex in 1963 that detergent manufacturers saw the tme possibiHties of enzymes. 

Until about 1950, the predominant method of producing industrial enzymes was by extraction from animal or plant sources by 1993, this accounts for less than 10%. With the exception of trypsin, chymosin, papain [9001 -73-2J, and a few others, industrial enzymes are now produced by microorganisms grown in aqueous suspension in large vessels, ie, by fermentation (qv). A smaH (5%) fraction is obtained by surface culture, ie, soHd-state fermentation, of microorganisms (13). 

Moreover, fermentation of various a-substituted cycloalkanone enol esters results in optically active six-, eight-, ten-, and twelve-membered ring ketones with 70—96% ee (84). Isolated enzymes catalyze similar transformations, bacillus coagulans and Candida glindracea]i 2Lse OF (Meito Sangyo) hydrolyze a number of cycHc and acycHc enol esters, giving ketones in 40—80% yield and 14—85% ee (85,86). 

Currently, a-amino acids are prepared by several routes such as by the fermentation of glucose, by enzyme action on several substances and by the hydrolysis of proteins. Many methods for synthesising the polymers are known, of which the polymerisation of A -carboxyanhydrides is of particular interest, as it yield-products of high molecular weight (Figure 18.24). 

Chelpin (Stockholm) investigations on the fermentation of sugars and fermentative enzymes. 

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