Characterization of anaerobic fermentative growth of Bacillus subtilis: identification of fermentation end products and genes required for growth.
AUTOR(ES)
Nakano, M M
RESUMO
Bacillus subtilis can grow anaerobically by respiration with nitrate as a terminal electron acceptor. In the absence of external electron acceptors, it grows by fermentation. Identification of fermentation products by using in vivo nuclear magnetic resonance scans of whole cultures indicated that B. subtilis grows by mixed acid-butanediol fermentation but that no formate is produced. An ace mutant that lacks pyruvate dehydrogenase (PDH) activity was unable to grow anaerobically and produced hardly any fermentation product. These results suggest that PDH is involved in most or all acetyl coenzyme A production in B. subtilis under anaerobic conditions, unlike Escherichia coli, which uses pyruvate formate lyase. Nitrate respiration was previously shown to require the ResDE two-component signal transduction system and an anaerobic gene regulator, FNR. Also required are respiratory nitrate reductase, encoded by the narGHJI operon, and moaA, involved in biosynthesis of a molybdopterin cofactor of nitrate reductase. The resD and resDE mutations were shown to moderately affect fermentation, but nitrate reductase activity and fnr are dispensable for fermentative growth. A search for genes involved in fermentation indicated that ftsH is required, and is also needed to a lesser extent for nitrate respiration. These results show that nitrate respiration and fermentation of B. subtilis are governed by divergent regulatory pathways.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=179605Documentos Relacionados
- Helical growth of Bacillus subtilis: a new model of cell growth.
- Identification and isolation of a gene required for nitrate assimilation and anaerobic growth of Bacillus subtilis.
- Mutational Analysis of the sbo-alb Locus of Bacillus subtilis: Identification of Genes Required for Subtilosin Production and Immunity
- Fermentative Metabolism of Bacillus subtilis: Physiology and Regulation of Gene Expression
- Anaerobic transcription activation in Bacillus subtilis: identification of distinct FNR-dependent and -independent regulatory mechanisms.