“…Besides two-enzyme systems, three-enzyme and fourenzyme systems are represented as well (Bae et al, 1999;Galkin et al, 1997;Hanson et al, 1992;Nakajima et al, 1990a,b;Soda et al, 2001;Yun et al, 2003). Several scientists studied such systems in which they used various enzyme combinations (Bae et al, 1999;Galkin et al, 1997;Nakajima et al, 1990b;Soda et al, 2001). In one article, Soda and co-workers (Soda et al, 2001) combined the action of D-amino acid aminotransferase, glutamate racemase, glutamate dehydrogenase, and FDH to obtain optically pure D-phenylalanine and D-tyrosine (Bae et al, 1999) without the additional by-products.…”