FOOD SCIENCE ›› 2017, Vol. 38 ›› Issue (2): 59-64.doi: 10.7506/spkx1002-6630-201702010

• Bioengineering • Previous Articles     Next Articles

Production of Optically Pure L-Phenyllactic Acid by Using Whole Cells of Recombinant Escherichia coli

ZHU Yibo, LU Rubin, CHENG Jun, WANG Ying, QI Bin, WANG Limei   

  1. 1. School of Biotechnology and Food Engineering, Changshu Institute of Technology, Suzhou 215500, China; 2. College of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China
  • Online:2017-01-25 Published:2017-01-16

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

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