Glucose isomerase, industrial application

Pedersen, S. (1993) Industrial aspects of immobilized glucose isomerase. Industrial Application of immobilized biocatalysts, edited by A.Tanaka, T.Tosa and T.Kobayashi. New York Marcel Dekker, Inc. 

Bacillus sp. These bacteria are gram-positive soil microbes. Members of the Bacillus species supply 58% of iadustrial enzymes sold (19). Eor example, proteases from B. amjloliquefaciens and amylases from B. licheniformis glucose isomerase from B. coagulans are used ia a variety of iadustrial processes (see Enzyme applications-industrial). The proteiaaceous iaclusioas produced by B. thuringiensis are useful as iasect toxias. Thus exteasive fermentation technology has been developed for Bacillus species and low cost media are available (19). 

Non-corrin cobalt has a number of interesting applications in the chemical industry, for example in the hydroformylation (OXO) reaction between CO, H2 and olefins. A number of non-corrin Co-containing enzymes have been described, including methionine aminopep-tidase, prolidase, nitrile hydratase and glucose isomerase. We describe the best characterized of these, namely the E. coli methionine aminopeptidase, a ubiquitous enzyme, which cleaves N-terminal methionine from newly translated polypeptide chains. The active site of the enzyme (Figure 15.13) contains two Co(II) ions that are coordinated by the side-chain atoms of five amino acid residues. The distance between the two Co2+ is similar to that between the two Zn2+ atoms in leucine aminopeptidase, and indeed the catalytic mechanism of methionine aminopeptidase shares many features with other metalloproteases, in particular leucine aminopeptidases. 

Jensen, V.J. and Rugli, S. (1987) Industrial scale production and application of immobilised glucose isomerase. Methods in Enzymology, 136, 356-370. 

When immobilized glucose isomerase was introduced in the early seventies, it was believed, that other industrial applications of immobihzed enzymes would soon be found, but this turned out not to be trae. The main limitation to the use of immobilized enzymes is that the substrate has to be soluble and highly purified in order to avoid clogging of the enzyme bed. In the case of glucose isomerase the cost of purifying the syrup (carbon treatment, ion exchange) before the fixed bed isomerase reactors is substantially higher than the enzyme costs. 

The food industry is a fertile area for biocatalysis applications high-fructose corn syrup (HFCS) from glucose with glucose isomerase, the thermolysin-catalyzed synthesis of the artificial sweetener Aspartame , hydrolysis of lactose for lactose-intolerant consumers, and the synthesis of the nutraceutical i-camitine in a two-enzyme system from "ybutyrobetaine all serve as examples. 

D-Xylose isomerase catalyzes the interconversion between D-xylose and D-xylulose (Fig. 17-21). Since this enzyme acts on D-glucose to produce D-fructose, it is often referred to as glucose isomerase (Fig. 17-21). The isomerization of glucose to fructose by this enzyme is a very important process for the industrial production of high fructose com syrup. This enzyme is also applicable to the synthesis of many aldoses and ketoses because of its wide substrate specificity. The enzyme gene has been cloned from various microorganisms, and the enzyme has been overexpressed, purified, and characterized. Their three dimensional structures have also been determined I203-206. ... 

Discovery of glucose isomerase is a contribution originated from Japan, leading to worldwide application in the sugar industry. In 1965, Sato and Tsumura [9] discovered the enzyme from Streptomyces strains, and the batch reactor system with the Streptomyces hyphae as a catalyst was developed soon afterwards. Industrial production of fructose + glucose syrup by combined use of glucose isomerase and glucoamylase started in 1971. 

Industrial applications represent more than 80% of the global market of enzymes. A distinction should be made between those cases in which the enzymatic conversion of the raw material into the product is the key operation and those in which the enzyme is used as an additive to modify certain functional property of the product. In the first case the enzymatic reaction is carried out in a controlled environment at optimized conditions with respect to the catalytic potential of the enzyme, while in the second case conditions for enzyme action are not specified to optimize its activity and sometimes not even controlled. Examples of the first case are the production of high-fructose syrups with immobilized glucose isomerase and the production of 6-aminopenicillanic acid from penicillin G with immobilized penicillin acylase examples of the second case are the use of fungal proteases in dough making and the use of pancreatin in leather bating. Most conventional uses of enzymes refer to... 

Glucose isomerase (actually xylose isomerase) is undoubtedly the most important and successful application of enzyme technology. Glucose isomerization by glucose isomerase was developed in the late 1960s but it was not until the mid-1970s when the process acquired industrial significance as a consequence of the... 

Most industrial enzymatic processes refer to reactions conducted by hydrolases in aqueous medium for the degradation of complex molecules (often polymers) into simpler molecules in conventional processes with limited added value (Neidelman 1991). Reasons underlying are clear since hydrolases are robust, usually extracellular and have no coenzyme requirements, which makes them ideal process biocatalysts. Enzyme immobilization widened the scope of application allowing less stable, intracellular and non-hydrolytic enzymes to be developed as process biocatalysts (Poulsen 1984 D Souza 1999), as illustrated by the paradigmatic case of glucose isomerase for the production of HFS (Carasik and Carroll 1983) and the production of acrylamide from acrylonitrile by nitrile hydratase (Yamada and Kobayashi 1996). 

The first commercial use of immobilized enzymes was developed in the mid-1960s, when amino acylase was used to separate racemates of L-amino acids by adsorption. Next came penicillin amadase for the production of semisynthetic penicillins. A major industrial application of immobilized enzymes was achieved in 1976 with the use of glucose isomerase to convert glucose to fructose. The first product was Sweetzyme developed by Novo Nordisk. Glucose was available as a by-product from the manufacture of cornstarch, but was not used as a sweetener because of its relative lack of sweetness (93). Because fructose tastes more than... 

Glucose isomerase catalyzes the conversion of glucose into fructose, resulting in a product sweeter in taste. This particular enzyme was produced by Streptomyces sp., which led to the significant industrial development based on the above application. 

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