Industrial enzymes processes

Enzyme—Heat—Enzyme Process. The enzyme—heat—enzyme (EHE) process was the first industrial enzymatic Hquefaction procedure developed and utilizes a B. subtilis, also referred to as B. amjloliquefaciens, a-amylase for hydrolysis. The enzyme can be used at temperatures up to about 90°C before a significant loss in activity occurs. After an initial hydrolysis step a high temperature heat treatment step is needed to solubilize residual starch present as a fatty acid/amylose complex. The heat treatment inactivates the a-amylase, thus a second addition of enzyme is required to complete the reaction. 

The detergent industry is the largest user of industrial enzymes. The starch industry, the first significant user of enzymes, developed special symps that could not be made by means of conventional chemical hydrolysis. These were the first products made entirely by enzymatic processes. Materials such as textiles and leather can be produced in a more rational way when using enzyme technology. Eoodstuffs and components of animal feed can be produced by enzymatic processes that require less energy, less equipment, or fewer chemicals compared with traditional techniques. 

Early Industrial Enzymes. Enzymes were used in ancient Greece for the production of cheese (9). Early references to this are found in Greek epic poems dating from about 800 BC. Fermentation processes for brewing, baking, and the production of alcohol have been known since prehistoric times. 

Worldwide consumption of industrial enzymes amounted to approximately 720 million in 1990 about one-third was accounted for by the U.S. market. Estimation of worldwide consumption is difficult because official production figures are scarce. A relatively large portion of the production of starch-processing enzymes is for internal consumption. Furthermore, the currency used for the estimation also influences the result considerably. 

The advantages of such biotransformation processes are (1) the relatively high yields which can be achieved with specific enzymes, (2) the formation of chiral compounds suitable for biopharmaceuticals, and (3) the relatively mild reaction conditions. Key issues in industrial-scale process development are achieving high product concentrations, yields and productivities by maintaining enzyme activity and stability under reaction conditions while reducing enzyme production costs. 

Since many years, pectolytic enzymes have been widely used in industrial beverage processing to improve either the quality and the yields in fruit juice extraction or the characteristics of the final product [1,2]. To this purpose, complex enzymatic mixtures, containing several pectolytic enzymes and often also cellulose, hemicellulose and ligninolytic activities, are usually employed in the free form. The interactions among enzymes, substrates and other components of fruit juice make the system very difficult to be investigated and only few publications are devoted to the study of enzymatic pools [3-5], An effective alternative way to carry out the depectinisation process is represented by the use of immobilized enzymes. This approach allows for a facile and efficient enzymatic reaction control to be achieved. In fact, it is possible to avoid or at least to reduce the level of extraneous substances originating from the raw pectinases in the final product. In addition, continuous processes can be set up. 

The high specific activity of enzymes and tfie tfieoretical possibility of using them to conduct electrochemical reactions are topics of great scientific interest. However, it is difficult to envisage prospects for a practical nse of enzymes for an acceleration and intensification of industrial electrode processes. The difficulty resides in the fact that enzymes are rather large molecnles, and on the surface of an enzyme electrode, fewer active sites are available than on other electrodes. Per unit snrface area, therefore, the effect expected from the nse of enzymes is somewhat rednced. 

A summary of the industrial-scale process development for the nitrilase-catalyzed [93] route to ethyl (/ )-4-cyano-3-hydroxy-butyrate, an intermediate in the synthesis of Atorvastatin (Pfizer Lipitor) from epichlorohydrin via 3-hydroxyglutaronitrile (3-HGN) was recently reported (Figure 8.15) [94], The reaction conditions were further optimized to operate at 3 m (330 gL ) substrate, pH 7.5 and 27 °C. Under these conditions, 100% conversion and product ee of 99% was obtained in 16 h reaction time with a crude enzyme loading of 6% (based on total protein, 0.1 U mg-1). It is noted that at pH < 6.0 the reaction stalled at <50% conversion and at alkaline pH a slowing in reaction rate was observed. Since the starting material is of low cost and the nitrilase can be effectively expressed in the Pfenex (Pseudomonas) expression system at low cost, introduction of the critical stereogenic center... 

Biocatalysts Ltd. is an independent company that since 1980 has been devoted to the manufacture and sales enzymes. Since it is not part of a larger chemical, food ingredients or pharmaceutical company, instead of producing large volumes of commodity enzymes, it produces enzymes tailored to customer needs. Their services include working together with customers to industrialize their processes or to produce specific required enzymes. Usually, these customer sectors do not require single enzyme entities, but enzyme complexes where the ratios of each of the components are crucial to the efficacy of the whole enzyme-biocatalyst product and to the customer s process. Fermentation requirements for the manufacture of enzyme products are sub-contracted out. 

The final development of the enzyme product after identification of the inhibitor and establishment of an industrial production process turned out relatively easy after initial solubility issues were solved. 

An enzyme is a protein that speeds up a biochemical reaction without itself experiencing any overall change. In chemical language, such a compound is called a catalyst and is said to catalyze a reaction. Chemists employ a variety of compounds as laboratory catalysts, and many industrial chemical processes would be impracticably slow without catalysis. An automobile s catalytic converter makes use of a metal catalyst to accelerate conversion of toxic carbon monoxide in the exhaust to carbon dioxide. Similarly, our bodies biochemical machinery effects thousands of different reactions that would not proceed without enzymatic catalysis. Some enzymes are exquisitely specific, catalyzing only one particular reaction of a single compound. Many others have much less exacting requirements and consequently exhibit broader effects. Specific or nonspecific, enzymes can make reactions go many millions of times faster than they would without catalysis. 

We have devised a very simple procedure for the preparative synthesis of various aldonic acids from the corresponding aldoses. This green chemistry process takes advantage of the availability of cheap, robust industrial enzymes. 

Both digester systems exhibit extremely low levels of detectable cellulase activities (exoglucanase, endoglucanase, and -glucosidase) when compared to industrial saccharifying processes (See Table III) in which the hydrolysis of cellulose in the feedstock is optimized with respect to enzyme loading. Therefore, the data indicate the level of improvement that may be made to attain maximum rates for cellulose hydrolysis in the anaerobic reactor system. 

Industrial enzymes are commonly used at levels of 0.1-0.5 per cent of the substrate being processed, with rare exceptions above these levels. Therefore, when the actual amount of any constituent of the preparation is evaluated as a constituent of the final processed product, it is unlikely that it will make a significant contribution in relation to other similar materials, present or introduced, in the total process. 

Polysaccharide degrading enzymes have a long history of commercial application in food processing, horticulture, agriculture, and protein research. As with most other industrial enzymes, the economic use of polysaccharidases often depends on obtaining the maximum activity lifetime in the process environment and/or securing a recovery system that permits the sensible reuse of active enzymes from process streams. 

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