Acetate and carbon dioxide assimilation byDesulfovibrio vulgaris(Marburg), growing on hydrogen and sulfate as sole energy source

✍ Scribed by Werner Badziong; Bernhard Ditter; Rudolf K. Thauer

• Book ID: 104760776
• Publisher: Springer
• Year: 1979
• Tongue: English
• Weight: 487 KB
• Volume: 123
• Category: Article
• ISSN: 0302-8933
• DOI: 10.1007/bf00406665

✦ Synopsis

Desulfovibrio vulgaris (Marburg) was grown on hydrogen plus sulfate as sole energy source and acetate plus CO 2 as the sole c a r b o n sources. The i n c o r p o r a t i o n of U-14C acetate into alanine, aspartate, glutamate, and ribose was studied. The labelling d a t a show that alanine is synthesized from one acetate (C-2 + C-3) and one COz (C-1), aspartate from one acetate (C-2 + C-3) and two CO 2 (C-I + C-4), glutamate from two acetate (C-1 -C -4 ) and one CO2 (C-5), and ribose from 1.8 acetate and 1.4 CO2. These findings indicate that in Desulfovibrio vulgaris (Marburg) pyruvate is formed via reductive carboxylation of acetyl-CoA, oxaloacetate via carboxylation of pyruvate or p h o s p h o e n o l pyruvate, and ~-ketoglutarate from oxaloacetate plus acetyl-CoA via citrate and isocitrate. Since C-5 of glutamate is derived from CO2, citrate must have been formed via a (R)-citrate synthase rather than a (S)-citrate synthase. The synthesis o f r i b o s e from 1.Stool of acetate and 1.4mol of CO 2 excludes the operation of the Calvin cycle in this chemolithotrophically growing bacterium.