Industrial Biocatalysts

Lipase Origin Candida cylindracea Biocatalysts Industrial... 

Biocatalyst An enzyme tliat plays a fundamental role in living organisms or in industry by activating or accelerating a bioprocess. 

Biotechnology has attracted enormous interest and high expectations over the past decade. However, the implementation of new technologies into industrial processes has been slower than initially predicted. Although biocatalytic methods hold great industrial potential, there are relatively few commercial applications of biocatalysts in organic chemical synthesis. The main factors that limit the application of biocatalysts are ... 

Apart from economic considerations, the inherent disadvantages of biocatalysts have also limited the transformation of new technologies into industrial processes. Table 2.3 lists the major drawbacks of bioprocesses. 

The industrial development of biotransfonmations is hampered currently by lack of commercial availability of biocatalysts at a reasonable price, insufficient operational stability of most biocatalysts and the practical problems associated with the exploitation of cofactor-dependent biocatalysts. 

Alcohol oxidoreductases capable of oxidizing short chain polyols are useful biocatalysts in industrial production of chiral hydroxy esters, hydroxy adds, amino adds, and alcohols [83]. In a metagenomic study without enrichment, a total of 24 positive clones were obtained and tested for their substrate specifidty. To improve the detedion frequency, enrichment was performed using glycerol or 1,2-propanediol and further 24 positive clones were deteded in this study. 

Despite the still growing number of available methods for the preparation of enantiopure compounds by the use ofasymmetric catalysis, kinetic resolution (KR) is still the most employed method in the industry [4], and in most cases biocatalysts (enzymes) are used. 

End N, Schoning K-U (2004) Immobilized Biocatalysts in Industrial Research and Production. 242 273-317... 

Biocatalytic Deracemization Dynamic Resolution, Stereoinversion, Enantioconvergent Processes and Cyclic Deracemization, in Biocatalysts in the Pharmaceutical and Biotechnology industries, (ed. R.N. Patel), CRC Press, Boca Raton, pp. 27-51. 

Special reactors are required to conduct biochemical reactions for the transformation and production of chemical and biological substances involving the use of biocatalysts (enzymes, immobilised enzymes, microorganisms, plant and animal cells). These bioreactors have to be designed so that the enzymes or living organisms can be used under defined, optimal conditions. The bioreactors which are mainly used on laboratory scale and industrially are roller bottles, shake flasks, stirred tanks and bubble columns (see Table 1). 

Some of the industrial biocatalysts are nitrile hydralase (Nitto Chemicals), which has a productivity of 50 g acrylamide per litre per hour penicillin G amidase (Smith Kline Beechem and others), which has a productivity of 1 - 2 tonnes 6-APA per kg of the immobilized enzyme glucose isomerase (Novo Nordisk, etc.), which has a productivity of 20 tonnes of high fmctose syrup per kg of immobilized enzyme (Cheetham, 1998). Wandrey et al. (2000) have given an account of industrial biocatalysis past, present, and future. It appears that more than 100 different biotransformations are carried out in industry. In the case of isolated enzymes the cost of enzyme is expected to drop due to an efficient production with genetically engineered microorganisms or higher cells. Rozzell (1999) has discussed myths and realities... 

Metabolic and enzyme engineering have received a lot of attention in academic institutions and are now being applied for the optimization of biocatalysts used in the production of a diverse range of products. Engineered microorganisms, even with non-native enzyme activities, are being used for novel products and process improvements for the production of precursors, intermediates and complete compounds, required in the pharmaceutical industry (Chartrain et ai, 2000). 

Chapters 1-4 serve as an introduction to emerging biocatalysts, modern expression hosts, state of the art of directed evolution, high-throughput screening, and bioprocess engineering for industrial applications. 

Purkarthofer, T., Skranc, W., Schuster, C. and Griengl, H. (2007) Potential and capabilities of hydroxynitrile lyases as biocatalysts in the chemical industry. Applied Microbiology and Biotechnology, 76, 309—320. 

Jennewein, S., Schurmann, M., Wolberg, M. et al. (2006) Directed evolution of an industrial biocatalyst 2-deoxy-D-ribose 5-phosphate aldolase. Biotechnology Journal, 1, 537-548. 

Chibata, L., Tosa, T. and Shibatani, T. (1992) The industrial production of optically active compounds by immobilized biocatalysts, in Chirality in Industry (eels A. X. Collins, G.N. Sheldrake and J. Crosby), John Wiley Sons, Ltd, New York, pp. 351-370. 

Wu, P.-H., Nair, G.R., Chu, I.-M. and Wu, W.-T. (2008) High cell density cultivation of Escherichia coli with surface anchored transglucosidase for use as whole-cell biocatalyst for a-arbutin synthesis. Journal of Industrial... 

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