title: [Screening of dissolved oxygen induced promoters in Corynebacterium crenatum and functional verification].
abstract: OBJECTIVE
  Purpose of this work was to screen promoters which were induced by dissolved oxygen in Corynebacterium crenatum SYPA5-5.
  
  
  METHODS
  Based on the genomic information of Corynebacterium, we identified target proteins which were the highest expression level of one copy of 27 known proteins from our earlier study. Based on the upstream sequence of the coding gene sequences, we amplified two promoters, named P-tkt and P-fum. The tac promoter of recombinant pDXW-8-cat and pDXW-8-gfp were replaced by the new promoters, and the recombinant plasmids were transformed into E. coli JM109 and C. crenatum SYPA5-5 respectively. At different dissolved oxygen level, we compared the function of promoters by the expression of chloramphenicol acetyltransferase (CAT) and green fluorescent protein (GFP).
  
  
  RESULTS
  Results show that we identified 2 target proteins, which were transketolase and fumarate hydratase. At the high dissolved oxygen level the CAT activity of E. coli JM109/pDXW-Ptkt-cat and C. crenatum SYPA5-5/pDXW-Ptkt-cat were 3.032 U/mg and 1.987 U/mg, which were 2.8-fold and 3.2-fold than that in the low dissolved oxygen, respectively. We got similar results by using a 5-L fermentor.
  
  
  CONCLUSIONS
  The P-tkt promoter induced by high dissolved oxygen was suitable for fermentation to produce amino acids and beneficial to improve ability of synthesis and metabolism of amino acids at high dissolved oxygen level.
authors.affiliation: Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
authors.forename: Bohui
authors.initials: B
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
authors.forename: Meijuan
authors.initials: M
authors.lastname: Xu
authors.affiliation: Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi 214122, China.
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Rao
authors.affiliation: School of Pharmaceutical Science, Jiangnan University, Wuxi 214122, China.
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Xu
mesh_terms: D003352:Corynebacterium / Q000201:enzymology / Q000235:genetics* / Q000378:metabolism; D005649:Fumarate Hydratase / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D010100:Oxygen / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D014174:Transketolase / Q000235:genetics / Q000378:metabolism
chemical_list: D014174:Transketolase; D005649:Fumarate Hydratase; D010100:Oxygen