Asymmetric biosynthesis of L-phosphinothricin by a novel transaminase from Pseudomonas fluorescens ZJB09-108

In this study, a new transaminase from Pseudomonas fluorescens ZJB09-108 (named as Pf-TA) was cloned and expressed in E. coli BL21 (DE3). The amino acid sequence analysis showed that the maximum sequence identity of Pf-TA with other transaminases is 74%. This recombinant Pf-TA exhibited a good temperature stability and pH stability. The Km and kcat of Pf-TA toward PPO were 34.02 mmol·L-1 and 11.3 s-1, respectively. After optimization of the L-PPT biosynthesis catalyzed by whole-cells of E. coli harboring transaminase,>99% yield of L-PPT with 99.9% of enantiomeric excess was attained at a PPO concentration of 100 mM. High yield of L-PPT (79%) with 99.9% enantiomeric excess was achieved at high PPO concentration of 500 mM as well. These results suggested the recombinant transaminase is a potential candidate for the biosynthesis of L-PPT from PPO.Graphical Abstract
Source: Process Biochemistry - Category: Biochemistry Source Type: research