title: Enhanced production of L-arginine by expression of Vitreoscilla hemoglobin using a novel expression system in Corynebacterium crenatum.
abstract: Corynebacterium crenatum SYPA 5-5 is an aerobic and industrial L: -arginine producer. It was proved that the Corynebacterium glutamicum/Escherichia coli shuttle vector pJC1 could be extended in C. crenatum efficiently when using the chloramphenicol acetyltransferase gene (cat) as a reporter under the control of promoter tac. The expression system was applied to over-express the gene vgb coding Vitreoscilla hemoglobin (VHb) to further increase the dissolved oxygen in C. crenatum. As a result, the recombinant C. crenatum containing the pJC-tac-vgb plasmid expressed VHb at a level of 3.4 nmol g(-1), and the oxygen uptake rates reached 0.25 mg A(562)(-1)  h(-1) which enhanced 38.8% compared to the wild-type strain. Thus, the final L: -arginine concentration of the batch fermentation reached a high level of 35.9 g L(-1), and the biomass was largely increased to 6.45 g L(-1), which were 17.3% and 10.5% higher than those obtained by the wild-type strain, respectively. To our knowledge, this is the first report that the efficient expression system was constructed to introduce vgb gene increasing the oxygen and energy supply for L: -arginine production in C. crenatum, which supplies a good strategy for the improvement of amino acid products.
authors.affiliation: The Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, People's Republic of China.
authors.forename: Meijuan
authors.initials: M
authors.lastname: Xu
authors.forename: Zhiming
authors.initials: Z
authors.lastname: Rao
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Chunyan
authors.initials: C
authors.lastname: Lan
authors.forename: Wenfang
authors.initials: W
authors.lastname: Dou
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Zhang
authors.forename: Hongyu
authors.initials: H
authors.lastname: Xu
authors.forename: Jian
authors.initials: J
authors.lastname: Jin
authors.forename: Zhenghong
authors.initials: Z
authors.lastname: Xu
mesh_terms: D001120:Arginine / Q000096:biosynthesis*; D001426:Bacterial Proteins / Q000378:metabolism*; D001709:Biotechnology / Q000379:methods*; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D003352:Corynebacterium / Q000166:cytology / Q000254:growth & development / Q000378:metabolism*; D015870:Gene Expression; D010100:Oxygen / Q000378:metabolism; D010957:Plasmids / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000235:genetics; D011995:Recombination, Genetic / Q000235:genetics; D013057:Spectrum Analysis; D014170:Transformation, Genetic; D054793:Truncated Hemoglobins / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D054793:Truncated Hemoglobins; C082613:hemoglobin protein, Vitreoscilla; D001120:Arginine; D015500:Chloramphenicol O-Acetyltransferase; D010100:Oxygen