Acrylic acid Biocatalysts

Acryl amide is an important bulk chemical used in coagulators, soil conditioners and stock additives. The chemical synthesis has several drawbacks because the rate of acryl amide formation is lower than the formation of the by-product acrylic acid [54]. Further, the double bonds of the reactants and products cause by-product formations as well as formation of polymerization products. As a result of optimization with methods of molecular engineering, a very high activity of the biocatalyst nitrile hydratase at low temperature is yielded, enabling a successful biotransformation that is superior to the chemical route. Here, the synthesis is carried out at a low temperature of about 5°C, showing a conversion of 100%. 

Thermal and pH sensitive heterogeneous copolymer hydrogels which contain silicone rubber domains within a temperature and pH sensitive copolymer of NIPA and acrylic acid have been synthesized by Dong et al. [60]. These materials contained macropores when swollen and collapsed much faster than homopolymers of iV-isopropylacrylamide. Biocatalyst immobilization using copolymers of NIPA and NN - dimethylaminopropylmethacrylamide have also been studied [61]. 

Biocatalysts that are reversibly soluble as a function of pH have been obtained by the covalent coupling of lysozyme to alginate (113) of trypsin to poly(acrolein-co-acrylic acid) (114) and of cellulase (115), amylase (115) a-chymotrypsin, and papain (116) to poly(methyl methacrylate-co-methacrylic acid). A reversibly soluble cofactor has been produced by the covalent binding of NAD to alginate (117). Reversibly soluble a-chymotrypsin, penicillin acylase, and alcohol dehydrogenase were produced by coupling to the polycation component of polyelectrolyte complexes formed by poly(methacrylic acid) and poly(iY-ethyl-4-vinyl-pyridinium bromide) (118). 

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