Metabolism of H2-CO2, methanol, and glucose by Butyribacterium methylotrophicum.
The fermentative metabolism of Butyribacterium methylotrophicum grown on either H2-CO2, methanol, glucose, or CO is described. The following reaction stoichiometries were obtained: 1.00 H2 + 0.52 CO2 leads to 0.22 acetate + 0.06 cell C; 1 methanol + 0.18 CO2 + 0.01 acetate leads to 0.24 butyrate + 0.29 cell C; and 1.00 glucose leads to 0.31 CO2 + 1.59 acetate + 0.21 butyrate + 0.13 H2 + 1.58 cell C. Cell yields of 1.7 g (dry weight) per mol of H2, 8.2 g (dry weight) per mol of methanol, 42.7 g (dry weight) per mol of glucose, and 3.0 g (dry weight) per mol of CO were obtained from linear plots of cell synthesis and substrate consumption. Doubling times of 9.0, 9.0, and 3 to 4 h were observed during batch growth on H2-CO2, methanol, and glucose, respectively. Indicative of a growth factor limitation, glucose fermentation in defined medium displayed a lower cell synthesis efficiency than when yeast extract (0.05%) was present. B. methylotrophicum fermentation displayed atypically high substrate/cell carbon synthesis conversion ratios for an anaerobe, as greater than 24% of the carbon was assimilated into cells during growth on methanol or glucose. The data indicate that B. methylotrophicum conserves carbon-bound electrons during growth on single-carbon or multicarbon substrates.
D002245:Carbon Dioxide / Q000378:metabolism*; D002248:Carbon Monoxide / Q000378:metabolism; D005051:Eubacterium / Q000254:growth & development / Q000378:metabolism*; D005285:Fermentation; D005947:Glucose / Q000378:metabolism*; D006859:Hydrogen / Q000378:metabolism*; D000432:Methanol / Q000378:metabolism*; D013997:Time Factors
D002245:Carbon Dioxide; D002248:Carbon Monoxide; D006859:Hydrogen; D005947:Glucose; D000432:Methanol