Biotransformation of L-ornithine from L-arginine using whole-cell recombinant arginase.

A recombinant arginase was generated for a whole-cell biotransformation system to convert L-arginine to L-ornithine in Escherichia coli. The gene ARG1 coding arginase from Bos taurus liver was synthesized and expressed in E. coli BL21 (DE3) via pETDuet-1. The recombinant arginase was used to catalyze L-arginine to L-ornithine and urea. The reaction was optimal at pH 9.5 and 37 °C. Manganese (10(-5 )M) and Emulsifier OP-10 [0.033 % (v/v)] could promote arginase activity. In a scale up study, L-arginine conversion rate reached 98 % with a final concentration of 111.52 g L-ornithine/l.