title: Enhancement of phenyllactic acid biosynthesis by recognition site replacement of D-lactate dehydrogenase from Lactobacillus pentosus.
abstract: OBJECTIVE
  The Tyr52 residue of D-lactate dehydrogenase (D-LDH) from Lactobacillus pentosus was replaced with small hydrophobic residues and overexpressed in E. coli BL21 (DE3) to enhance 3-phenyllactic acid (PLA) synthesis by whole-cell catalyst.
  
  
  RESULTS
  Escherichia coli pET-28a-d-ldh produced 12.2 g PLA l(-1) in 3 h, with a molar conversion rate of 61 %, while E. coli pET-28a-d-ldh (Y52V) produced 15.6 g PLA l(-1), with a molar conversion rate of 77 %. This study demonstrates the feasibility of using engineered E. coli for PLA production from phenylpyruvate (PPA) and showed that site-directed mutagenesis of d-ldh markedly improved PLA yield and substrate conversion rate.
  
  
  CONCLUSIONS
  This biocatalytic system is a promising platform for PLA production from PPA.
authors: School of Biotechnology and Food Engineering, Changshu Institute of Technology, Changshu, 215500, Jiangsu, People's Republic of China, centuryrain@126.com.
authors: Yibo
authors: Y
authors: Zhu
authors: Fagen
authors: F
authors: Hu
authors: Yingyue
authors: Y
authors: Zhu
authors: Limei
authors: L
authors: Wang
authors: Bin
authors: B
authors: Qi
mesh_terms: D019943:Amino Acid Substitution; D053898:Biosynthetic Pathways / Q000235:genetics; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D045022:Lactate Dehydrogenases / Q000235:genetics / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism*; D007778:Lactobacillus / Q000201:enzymology* / Q000235:genetics; D060847:Metabolic Engineering / Q000379:methods*; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D007773:Lactates; D011994:Recombinant Proteins; C017648:3-phenyllactic acid; D045022:Lactate Dehydrogenases; C071195:D-lactate dehydrogenase