关键词: L-2-羟基-3-苯基丙酸, 巨大芽孢杆菌Z2013513, L-乳酸脱氢酶, 葡萄糖脱氢酶, NADH再生, 全细胞催化

Abstract: The L-lactate dehydrogenase gene (ldhL) and glucose dehydrogenase gene (gdh) were respectively amplified from Bacillus megaterium Z2013513 by PCR and inserted into the plasmid pETDuet-1 to construct the recombinant vector pETDuet-ldhL-gdh. Then, the vector was transformed into Escherichia coli BL21 (DE3) to obtain the recombinant strain E. coli BL21(DE3)/pETDuet-ldhL-gdh. Sodium dodecyl sulfate polyacrylamide gel electrophoresis and enzymatic activity analysis showed that both ldhL and gdh were successfully co-expressed with biological functions in the recombinant strain. Using whole cells of recombinant E. coli BL21(DE3)/pETDuet-ldhL-gdh, 24.26 mmol/L L-phenyllactic acid was obtained from phenylpyruvic acid at 37 ℃ and 200 r/min after 60 min transformation. The product enantiomeric excess percent was over 99% with substrate molar conversion rate of 59.55%. The results showed the cofactor regeneration biotransformation system was capable of efficiently producing optically pure L-phenyllactic acid.

Key words: L-2-hydroxyl-3-phenylpropionic acid, Bacillus megaterium Z2013513, L-lactate dehydrogenase, glucose dehydrogenase, NADH regeneration, whole-cell catalysis