Enzyme preparation, industrial

Recovery. The principal purpose of recovery is to remove nonproteinaceous material from the enzyme preparation. Enzyme yields vary, sometimes exceeding 75%. Most industrial enzymes are secreted by a microorganism, and the first recovery step is often the removal of whole cells and other particulate matter (19) by centrifugation (20) or filtration (21). In the case of ceU-bound enzymes, the harvested cells can be used as is or dismpted by physical (eg, bead mills, high pressure homogenizer) and/or chemical (eg, solvent, detergent, lysozyme [9001 -63-2] or other lytic enzyme) techniques (22). Enzymes can be extracted from dismpted microbial cells, and ground animal (trypsin) or plant (papain) material by dilute salt solutions or aqueous two-phase systems (23). 

For preparative purposes fermenting baker s yeast (Saccharomyces cerevisiae) is commonly used instead of a purified enzyme preparation. However, isolated pyruvate decarboxylates can also be used30. In this context, the most important substrate is benzaldehyde31 which is converted by n-glucosc fermenting yeast to (7 )-l-hydroxy-l-phenyl-2-propanone. This conversion has gained considerable industrial importance because ( )-l-hydroxy-1-phenyl-2-propanonc is an important precursor for the synthesis of (-)-cphedrin. 

However, if theoritically, the combination of pectinases to cellobiohydrolases plus endo-glucanases should release more than 80% of all polysaccharides from the cell walls (according to Voragen and al. [4]), in industrial conditions, we arrive almost at this level of degradation but only for the pectin. Commercial enzymes preparations contain pectinases, hemicellulases and cellulases. 

Biopract provides technological products and processes for industry, agriculture, and environment. They not only produce technical enzyme preparations but also develop enzymes for applications in agriculture, food, and textile industry as well as in environmental technologies. On the later, bioremediation has been an area of service delivery from Biopract. Their activities regards microbial preparations for the bioremediation of organic contaminants (mineral oil (MKW), polycyclic aromatic hydrocarbons (PAH), benzene, toluene, ethylbenzene, xylene (BTEX), methyl-tert-butyl ether (MTBE), volatile organic hydrocarbons (VOC), and dimethyl sulfoxide (DMSO)). 

It should be noted that some commercial enzyme preparations may contain several enzyme isomers (enzymes derived from one source which belong to the same enzyme class but differ in specificity, stability or other properties). This is most often the case when the commercial preparation was developed for a process industry application rather than a specific chemical biotransformation application. Some fungal enzymes, such as laccase, are sometimes supplied as crude enzyme mixtures. Fungal laccases are manufactured on a huge scale (multitonne per annum) and are principally used in bulk processes such as wood... 

The pharmaceutical and fine chemical industry might use pure hydrogenase or partially purified enzyme preparations in bioconversion applications such as regio and stereoselective hydrogenation of target compounds (van Berkel-Arts et al. 1986). Enzymes are able to catalyse such stereospecific syntheses with ease. However, the cofactors for the NAD-dependent oxidoreductases are expensive. The pyridine nucleotide-dependent hydrogenases such as those from Ralstonia eutropha and hyperthermophilic archaea (Rakhely et al. 1999) make it possible to exploit H2 as a low-cost reductant. The use of inverted micelles in hydrophobic solvents, in which H2 is soluble, has advantages in that the enzymes appear to be stabilized. 

Endo-xylanases can be used industrially in two ways 1) to remove xylan from paper pulp to give purer cellulose, and 2) to convert xylan into D-xylose or xylo-oligo-sac jharides that can be further converted into useful materials. In the first case, at least, it is clear that the enzyme preparation should be free of cellulases, either by (hoosing, or producing by mutation, a strain that makes xylanases but not cellulases, or by separating the lattCT from the former after they are produced. In nearly all cases t tie use of a cellulase-firee strain is preferable. 

Two broad areas of application for xylanolytic enzymes have been identified (1). The first involves the use of xylanases with other hydrolytic enzymes in the bioconversion of wastes such as those from the forest and agricultural industries, and in the clarification and liquification of juices, vegetables and fruits. For these purposes, the enzyme preparations need only to be filtered and concentrated as essentially no further purification is required. Several specific examples of applications involving crude xylanase preparations include bioconversion of cellulosic materials for subsequent fermentation (2) hydrolysis of pulp waste liquors and wood extractives to monomeric sugars for subsequent production of single cell protein (3-5). Xylose produced by the action of xylanases can be used for subsequent production of higher value compounds such as ethanol (6), xylulose (7) and xyIonic acid (8-9). 

Several methods to prepare high-purity xylanases for potential industrial applications have focused on eliminating the cellulase contamination instead of purifying the xylanase components. This appears to be a very effective approach as it precludes the need for very expensive biochemical procedures and focuses, rather, on a limited number of simple steps to eliminate cellulase activity. Since the remaining materials in the enzyme preparation are essentially inert with respect to the cellulose, their presence may often be ignored. 

The first company based upon applied biocatalysis also dates back to the 19 century. In 1874 Christian Hansen started a company in Copenhagen, Denmark. His company— named Christian Hansen s Laboratory to this day—was the first in the industrial market with a standardized enzyme preparation, rennet, for cheese making. Rennet, a mixture of chymosin (also called rennin) and pepsin, was and still is obtained by salt extraction of the fonrth stomach of suckling calves. 

Industries marketing enzyme preparations as (part of) the product to the final customer are described in this category. 

The industries discussed under this heading nse enzyme preparations to facilitate processing, to prevent technical problems and to reduce wastes. 

A. C. Hulme, Production and Application of Enzyme Preparations in Food Manufacture, Society of Chemical Industry, London, 1961. 

Several lactases suitable for industrial processing of whey or lactose are available. The enzyme prepared from the yeast Kluveromyces lactis has a pH optimum between 6 and 7 and a temperature optimum of about 35 °C. The lactase from K. fragilis has a pH optimum of 4.8 and a temperature optimum of about 50°C (MacBean 1979). 

ENZYME PREPARATIONS. Dorirg the pasi several years, a number of coiunieiviiilly prepared enzyme preparations have been available to processors, notably for use in the food industry These preparations fall imo three basic categories ill Annual-derived preparations i2i plant-derived preparations and (3) microhially derived preparations. 

Malted barley contains a- and p-amylases along with proteases and phytases. Most standardized microbial enzyme preparations for industrial starch conversion contain approximately 100 times more amylase activity than malt. In beermaking, malt is not just valuable for its enzymes but also for flavor compounds. 

New enzymes for organic synthesis continue to represent a challenge both for those who prepare them as well as for those who finally apply them. The improved accessibility of enzymes as industrial catalysts has led to a large number of practical processes. The times are long past when it was believed that, at best, hydrolases would be suitable for industrial operations. Today, there are examples of practical applications for almost all enzyme classes. 

The use of lipases in wastewater treatment in the food industry has been proposed to improve process efficiency (1,2). However, economical feasibility depends on low-cost enzyme preparations. Lipase production... 

Cyanidase, a commercial enzyme preparation, can convert cyanide in industrial wastewaters to ammonia and formate in what appears to be a single-step reaction [56], as follows ... 

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