Abstract
Previous work showed that Methanobacillus omelianskii was a mixed culture of an ethanol-oxidizing organism called S organism and a hydrogen-utilizing methane bacterium, strain MOH. S organism grows poorly on ethanol unless a hydrogen-utilizing methanogenic bacterium is included to utilize the H2 produced during growth. Further studies have shown that, among many substrates tested, only ethanol, n-propanol, n-butanol, isobutanol, n-pentanol, acetaldehyde, oxalacetate, and pyruvate are fermented by S organism, either alone or in combination with Methanobacterium ruminantium. It grew better in pure culture with pyruvate than with alcohols. H2 gas phase inhibited growth on pyruvate as well as on alcohol. When grown alone on pyruvate, S organism produced mainly acetate, ethanol, and CO2, in addition to a small amount of H2. When combined with M. ruminantium, no H2 and very little ethanol were produced and acetate production was increased. When M. ruminantium was present, electrons from pyruvate oxidation by S organism were channeled almost entirely to H2 and hence to methane formation rather than ethanol. Also, S organism utilized more pyruvate when grown with M. ruminantium. Attempts to obtain better growth of S organism on ethanol by addition of many possible electron acceptors were unsuccessful. It grew best between 32 and 45 C, had a per cent guanine plus cytosine content of deoxyribonucleic acid bases of 47.27 ± 0.1, contained no cytochrome, and could be grown on a defined medium with pyruvate as the energy and carbon source and with (NH4)2SO4 as the main nitrogen source. These and other results suggest that S organism belongs in a new genus, but assignment of a definite taxonomic status should await isolation and characterization of more strains.
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Selected References
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- Barker H. A. Studies on the Methane Fermentation: VI. The Influence of Carbon Dioxide Concentration on the Rate of Carbon Dioxide Reduction by Molecular Hydrogen. Proc Natl Acad Sci U S A. 1943 Jun;29(6):184–190. doi: 10.1073/pnas.29.6.184. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bryant M. P., McBride B. C., Wolfe R. S. Hydrogen-oxidizing methane bacteria. I. Cultivation and methanogenesis. J Bacteriol. 1968 Mar;95(3):1118–1123. doi: 10.1128/jb.95.3.1118-1123.1968. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Bryant M. P., Wolin E. A., Wolin M. J., Wolfe R. S. Methanobacillus omelianskii, a symbiotic association of two species of bacteria. Arch Mikrobiol. 1967;59(1):20–31. doi: 10.1007/BF00406313. [DOI] [PubMed] [Google Scholar]
- Campbell L. L., Postgate J. R. Classification of the spore-forming sulfate-reducing bacteria. Bacteriol Rev. 1965 Sep;29(3):359–363. doi: 10.1128/br.29.3.359-363.1965. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HUNGATE R. E. The anaerobic mesophilic cellulolytic bacteria. Bacteriol Rev. 1950 Mar;14(1):1–49. doi: 10.1128/br.14.1.1-49.1950. [DOI] [PMC free article] [PubMed] [Google Scholar]
- JOHNS A. T., BARKER H. A. Methane formation; fermentation of ethanol in the absence of carbon dioxide by Methanobacillus omelianskii. J Bacteriol. 1960 Dec;80:837–841. doi: 10.1128/jb.80.6.837-841.1960. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SADANA J. C. Pyruvate oxidation in Desulphovibrio desulphuricans. J Bacteriol. 1954 May;67(5):547–553. doi: 10.1128/jb.67.5.547-553.1954. [DOI] [PMC free article] [PubMed] [Google Scholar]
- SMITH P. H., HUNGATE R. E. Isolation and characterization of Methanobacterium ruminantium n. sp. J Bacteriol. 1958 Jun;75(6):713–718. doi: 10.1128/jb.75.6.713-718.1958. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wolin E. A., Wolfe R. S., Wolin M. J. Viologen dye inhibition of methane formation by Methanobacillus omelianskii. J Bacteriol. 1964 May;87(5):993–998. doi: 10.1128/jb.87.5.993-998.1964. [DOI] [PMC free article] [PubMed] [Google Scholar]