Publications (2)4.7 Total impact
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Article: Elucidation of genes relevant to the microaerobic growth of Corynebacterium glutamicum.
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ABSTRACT: Mutagenized cell libraries of Corynebacterium glutamicum were screened for mutants that lost the ability to grow under low oxygen concentrations. The resulting high-oxygen-requiring mutants were used to clone wild-type DNA fragments that could complement the phenotype. Sequencing and subcloning analyses identified six genes, Cgl0807, Cgl1102, Cgl0600, Cgl1427, Cgl2857, and Cgl2859, as the genes responsible for complementation. Some of these genes showed cross-complementation of the mutants in oxygen-limiting static culture, suggesting the utility of these genes for improved growth and production under oxygen limitation.Bioscience Biotechnology and Biochemistry 12/2009; 73(12):2806-8. · 1.28 Impact Factor -
Article: Anaerobic growth and potential for amino acid production by nitrate respiration in Corynebacterium glutamicum.
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ABSTRACT: Oxygen limitation is a crucial problem in amino acid fermentation by Corynebacterium glutamicum. Toward this subject, our study was initiated by analysis of the oxygen-requiring properties of C. glutamicum, generally regarded as a strict aerobe. This organism formed colonies on agar plates up to relatively low oxygen concentrations (0.5% O(2)), while no visible colonies were formed in the absence of O(2). However, in the presence of nitrate (NO3-), the organism exhibited limited growth anaerobically with production of nitrite (NO2-), indicating that C. glutamicum can use nitrate as a final electron acceptor. Assays of cell extracts from aerobic and hypoxic cultures yielded comparable nitrate reductase activities, irrespective of nitrate levels. Genome analysis revealed a narK2GHJI cluster potentially relevant to nitrate reductase and transport. Disruptions of narG and narJ abolished the nitrate-dependent anaerobic growth with the loss of nitrate reductase activity. Disruption of the putative nitrate/nitrite antiporter gene narK2 did not affect the enzyme activity but impaired the anaerobic growth. These indicate that this locus is responsible for nitrate respiration. Agar piece assays using L-lysine- and L-arginine-producing strains showed that production of both amino acids occurred anaerobically by nitrate respiration, indicating the potential of C. glutamicum for anaerobic amino acid production.Applied Microbiology and Biotechnology 08/2007; 75(5):1173-82. · 3.42 Impact Factor
