Premium
Repeated batch production of L ‐phenylalanine from phenylpyruvate and NH 4 Cl by immobilized cells of Nocardia opaca under hydrogen high pressure
Author(s) -
Matsunaga Tadashi,
Higashijima Michio,
Sulaswatty Anny,
Nishimura Shigeo,
Kitamura Takanori,
Tsuji Masao,
Kawaguchi Toshio
Publication year - 1988
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.260310811
Subject(s) - phenylalanine , chemistry , dehydrogenase , incubation , biochemistry , amino acid , food science , enzyme
Among various microbial cells examined under screening conditions, Nocardia opaca showed the highest activity for production of phenylalanine from phenylpyruvate. Here NH 4 Cl as well as amino acids were used as an amino donor for phenylalanine production. The phenylalanine production rate increased with increasing hydrogen pressure. The specific activity of phenylalanine dehydrogenase was increased by culturing N. opaca cells in nutrient broth containing 0.3% phenylalanine. As a result, the phenylalanine production rate increased from 0.69 to 4.4 μmol/min g dry cells. Immobilized cells were activated in nutrient broth containing ZnCl 2 before phenylalanine production. Phenylalanine dehydrogenase activity and cell number in the gel increased with increasing incubation time, and the maximum phenylalanine dehydrogenase activity was obtained at 36 h incubation. Then, phenylalanine was produced from phenylpyruvate, NH 4 Cl, and 100 atm H 2 with the activated immobilized cells. The rate of phenylalanine production was 0.24 μmol/min cm 3 gel. The conversion of phenylpyruvate to phenylalanine was 82%. Immobilized cells retained 76% of the initial phenylalanine production rate after 10 h reactions were repeated 11 times with two intervening reactivations.