Anaerobic growth of Corynebacterium glutamicum using nitrate as a terminal electron acceptor.
Corynebacterium glutamicum, a gram-positive soil bacterium, has been regarded as an aerobe because its growth by fermentative catabolism or by anaerobic respiration has, to this date, not been demonstrated. In this study, we report on the anaerobic growth of C. glutamicum in the presence of nitrate as a terminal electron acceptor. C. glutamicum strains R and ATCC13032 consumed nitrate and excreted nitrite during growth under anaerobic, but not aerobic, conditions. This was attributed to the presence of a narKGHJI gene cluster with high similarity to the Escherichia coli narK gene and narGHJI operon. The gene encodes a nitrate/nitrite transporter, whereas the operon encodes a respiratory nitrate reductase. Transposonal inactivation of C. glutamicum narG or narH resulted in mutants with impaired anaerobic growth on nitrate because of their inability to convert nitrate to nitrite. Further analysis revealed that in C. glutamicum, narK and narGHJI are cotranscribed as a single narKGHJI operon, the expression of which is activated under anaerobic conditions in the presence of nitrate. C. glutamicum is therefore a facultative anaerobe.
Nishimura
Taku
T
Microbiology Research Group, Research Institute of Innovative Technology for the Earth, 9-2 Kizugawadai, Kizu-cho, Soraku-gun, Kyoto 619-0292, Japan.
Vertès
Alain A
AA
Shinoda
Yoshifumi
Y
Inui
Masayuki
M
Yukawa
Hideaki
H
D000693:Anaerobiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D004926:Escherichia coli / Q000235:genetics; D015964:Gene Expression Regulation, Bacterial; D050901:Nitrate Reductase / Q000235:genetics / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D009876:Operon; D010084:Oxidation-Reduction; D012329:RNA, Bacterial / Q000235:genetics
D001426:Bacterial Proteins; D009566:Nitrates; D012329:RNA, Bacterial; D050901:Nitrate Reductase