title: Co-expression of L-glutamate oxidase and catalase in Escherichia coli to produce α-ketoglutaric acid by whole-cell biocatalyst.
abstract: OBJECTIVE
  To improve the production of α-ketoglutaric acid (α-KG) from L-glutamate by whole-cell biocatalysis.
  
  
  RESULTS
  A novel and highly active L-glutamate oxidase, SmlGOX, from Streptomyces mobaraensis was overexpressed and purified. The recombinant SmlGOX was approx. 64 kDa by SDS-PAGE. SmlGOX had a maximal activity of 125 ± 2.7 U mg-1at pH 6.0, 35oC. The apparent Kmand Vmaxvalues of SmlGOX were 9.3 ± 0.5 mM and 159 ± 3 U mg-1, respectively. Subsequently, a co-expression plasmid containing the SmlGOX and KatE genes was constructed to remove H2O2, and the protein levels of SmlGOX were improved by codon optimization. Finally, by optimizing the whole-cell transformation conditions, the production of α-KG reached 77.4 g l-1with a conversion rate from L-glutamate of 98.5% after 12 h.
  
  
  CONCLUSIONS
  An efficient method for the production of α-KG was established in the recombinant Escherichia coli, and it has a potential prospect in industrial application.
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457, China.
authors.forename: Qingdai
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Key Laboratory of Food Nutrition and Safety, Ministry of Education, Tianjin University of Science and Technology, Tianjin, 300457, China.
authors.forename: Xiaoqian
authors.initials: X
authors.lastname: Ma
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.|Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
authors.forename: Haijiao
authors.initials: H
authors.lastname: Cheng
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.|Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Xu
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. liu_jun@tib.cas.cn.|Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China. liu_jun@tib.cas.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Liu
authors.affiliation: Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.|Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
authors.forename: Yanhe
authors.initials: Y
authors.lastname: Ma
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D019149:Bioreactors / Q000382:microbiology*; D002374:Catalase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D006863:Hydrogen-Ion Concentration; D007656:Ketoglutaric Acids / Q000032:analysis / Q000378:metabolism*; D060847:Metabolic Engineering; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D013302:Streptomyces / Q000201:enzymology* / Q000235:genetics; D013696:Temperature; D014170:Transformation, Genetic
chemical_list: D001426:Bacterial Proteins; D007656:Ketoglutaric Acids; D011994:Recombinant Proteins; D002374:Catalase; D000594:Amino Acid Oxidoreductases; C023061:L-glutamate oxidase
keywords: L-Glutamate oxidase; Streptomyces mobaraensis; Whole-cell biocatalyst; α-Ketoglutaric acid