Fermentation of trans-aconitate via citrate, oxaloacetate, and pyruvate by Acidaminococcus fermentans.
Growing cells of Acidaminococcus fermentans (DSM 20731 and ATCC 25085) fermented trans-aconitate via citrate, oxaloacetate, and pyruvate to approximately 2 CO2, 1.8 acetate, 0.1 butyrate and 0.9 H2. The carbon and electron recoveries were close to 100%. On citrate no growth was observed and washed cells were unable to ferment this tricarboxylate. In cell-free extracts, however, citrate as well as trans-aconitate were readily fermented to CO2 and acetate. Under these conditions, also cis-aconitate, oxaloacetate, and pyruvate were formed, whereas butyrate and intermediates of glutamate fermentation, 2-oxoglutatrate and glutaconate, could not be detected. Citrate Si-lyase, a Mg2+-dependent oxaloacetate decarboxylase, and pyruvate synthase were present in quantities that corresponded to the growth rate of the organism.
Härtel
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U
Laboratorium für Mikrobiologie, Fachbereich Biologie, Philipps-Universität, D-35032 Marburg, Germany. buckel@mailer.uni-marburg.de
Buckel
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W
D000156:Aconitic Acid / Q000378:metabolism*; D002457:Cell Extracts; D002849:Chromatography, Gas; D019343:Citric Acid / Q000378:metabolism*; D005285:Fermentation; D018698:Glutamic Acid / Q000378:metabolism; D006089:Gram-Negative Anaerobic Bacteria / Q000378:metabolism*; D007536:Isomerism; D010071:Oxaloacetates / Q000378:metabolism*; D019289:Pyruvic Acid / Q000378:metabolism*
D002457:Cell Extracts; D010071:Oxaloacetates; D019343:Citric Acid; D018698:Glutamic Acid; D019289:Pyruvic Acid; D000156:Aconitic Acid