Effect of dilution rate on metabolic pathway shift between aceticlastic and nonaceticlastic methanogenesis in chemostat cultivation.

ABSTRACT: Acetate conversion pathways of methanogenic consortia in acetate-fed chemostats at dilution rates of 0.025 and 0.6 day(-1) were investigated by using (13)C-labeled acetates, followed by gas chromatography-mass spectrometry (GC-MS) analysis of the CH(4) and CO(2) produced. Nonaceticlastic syntrophic oxidation by acetate-oxidizing syntrophs and hydrogenotrophic methanogens was suggested to occupy a primary pathway (approximately 62 to 90%) in total methanogenesis at the low dilution rate. In contrast, aceticlastic cleavage of acetate by aceticlastic methanogens was suggested to occupy a primary pathway (approximately 95 to 99%) in total methanogenesis at the high dilution rate. Phylogenetic analyses of transcripts of the methyl coenzyme M reductase gene (mcrA) confirmed that a significant nu

SUBMITTER: Shigematsu T 

PROVIDER: S-EPMC444765 | biostudies-literature | 2004 Jul

REPOSITORIES: biostudies-literature