Naslov
Enzymatic production of L-phenylalanine from the racemic mixture of D, L-phenyllactate. Modelling of the reactor

Autori
Schmidt, Elke ; Vasić-Rački, Đurđa ; Wandrey, Christian

Izvornik
Applied Microbiology and Biotechnology (0175-7598) 26 (1987); 42-48

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
mathematical modeling; enzyme membrane reactor; L-phenylalanine production

Sažetak
The production of L-phenylalanine from the racemate D, L-phenyllactate in an enzyme membrane reactor has been examined. In a first step the racemate is dehydrogenated to the prochiral intermediate phenylpyruvate by the enzymes D- and L-hydroxyisocaproate dehydrogenase. In a second step phenylpyruvate is reductively aminated to L-phenylalanine by l-phenylalanine dehydrogenase. Both steps are dependent on coenzyme, the first one requires NAD, the second one NADH in stoichiometric amounts ; in this way the coenzyme is regenerated and only required catalytically. The coenzyme is covalently bound to polyethylene glycol-20000 and can thus be retained in the reactor analogously to the three enzymes. In order to optimize the continuous production of L-phenylalanine from D, L-phenyllactate, models of the reaction kinetics and of the reactor system have been set up. By means of the reactor model, we can calculate the optimum ratio of three enzymes, the optimum coenzyme concentration and the optimum phenylpyruvate concentration in the feed. In this process, at a substrate concentration of 50 mM D, L-phenyllactate we reached a space-time-yield of 28 g L-Phe/(l*d).

Izvorni jezik
Engleski

Znanstvena područja
Biotehnologija

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