Abstract
The effect of four saturated long-chain fatty acids (caprylic, capric, lauric, and myristic) and one unsaturated long-chain fatty acid (oleic) on the microbial formation of methane from acetate was investigated in batch anaerobic toxicity assays. The tests were carried out with granular sludge from an upflow anaerobic sludge bed reactor. In this sludge, Methanothrix spp. are the predominant acetoclastic methanogens. Lauric acid appeared to be the most versatile inhibitor: inhibition started at 1.6 mM, and at 4.3 mM the maximum specific acetoclastic methanogenic activity had been reduced to 50%. Caprylic acid appeared to be only slightly inhibitory. Oleic acid was almost as inhibitory as lauric acid. Although adsorption of the inhibitor on the cell wall might play an important role in the mechanism of inhibition, the inhibition was found to be correlated with concentration rather than with the amount per unit of biomass. In practical situations, as in anaerobic waste treatment processes, synergism can be expected to enhance the inhibition of methanogenesis. In the present research a background concentration of lauric acid below its MIC strongly enhanced the toxicity of capric acid and (to an even greater extent) myristic acid.
Full text
PDFSelected References
These references are in PubMed. This may not be the complete list of references from this article.
- Blaxter K. L., Czerkawski J. Modifications of the methane production of the sheep by supplementation of its diet. J Sci Food Agric. 1966 Sep;17(9):417–421. doi: 10.1002/jsfa.2740170907. [DOI] [PubMed] [Google Scholar]
- CAMIEN M. N., DUNN M. S. Saturated fatty acids as bacterial antimetabolites. Arch Biochem Biophys. 1957 Aug;70(2):327–345. doi: 10.1016/0003-9861(57)90121-2. [DOI] [PubMed] [Google Scholar]
- Czerkawski J. W., Blaxter K. L., Wainman F. W. The effect of linseed oil and of linseed oil fatty acids incorporated in the diet on the metabolism of sheep. Br J Nutr. 1966;20(3):485–494. doi: 10.1079/bjn19660048. [DOI] [PubMed] [Google Scholar]
- Czerkawski J. W., Breckenridge G. Fermentation of various soluble carbohydrates by rumen micro-organisms with particular reference to methane production. Br J Nutr. 1969 Nov;23(4):925–937. doi: 10.1079/bjn19690104. [DOI] [PubMed] [Google Scholar]
- Demeyer D. I., Henderickx H. K. The effect of C18 unsaturated fatty acids of methane production in vitro by mixed rumen bacteria. Biochim Biophys Acta. 1967 Jun 6;137(3):484–497. doi: 10.1016/0005-2760(67)90130-0. [DOI] [PubMed] [Google Scholar]
- Galbraith H., Miller T. B., Paton A. M., Thompson J. K. Antibacterial activity of long chain fatty acids and the reversal with calcium, magnesium, ergocalciferol and cholesterol. J Appl Bacteriol. 1971 Dec;34(4):803–813. doi: 10.1111/j.1365-2672.1971.tb01019.x. [DOI] [PubMed] [Google Scholar]
- Galbraith H., Miller T. B. Physicochemical effects of long chain fatty acids on bacterial cells and their protoplasts. J Appl Bacteriol. 1973 Dec;36(4):647–658. doi: 10.1111/j.1365-2672.1973.tb04150.x. [DOI] [PubMed] [Google Scholar]
- Glassman H. N. SURFACE ACTIVE AGENTS AND THEIR APPLICATION IN BACTERIOLOGY. Bacteriol Rev. 1948 Jun;12(2):105–148. doi: 10.1128/br.12.2.105-148.1948. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HASSINEN J. B., DURBIN G. T., BERNHARDT F. W. The bacteriostatic effects of saturated fatty acids. Arch Biochem Biophys. 1951 Apr;31(2):183–189. doi: 10.1016/0003-9861(51)90204-4. [DOI] [PubMed] [Google Scholar]
- Kabara J. J., Vrable R. Antimicrobial lipids: natural and synthetic fatty acids and monoglycerides. Lipids. 1977 Sep;12(9):753–759. doi: 10.1007/BF02570908. [DOI] [PubMed] [Google Scholar]
- NIEMAN C. Influence of trace amounts of fatty acids on the growth of microorganisms. Bacteriol Rev. 1954 Jun;18(2):147–163. doi: 10.1128/br.18.2.147-163.1954. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Prins R. A., van Nevel C. J., Demeyer D. I. Pure culture studies of inhibitors for methanogenic bacteria. Antonie Van Leeuwenhoek. 1972;38(3):281–287. doi: 10.1007/BF02328099. [DOI] [PubMed] [Google Scholar]
- Zehnder A. J., Huser B. A., Brock T. D., Wuhrmann K. Characterization of an acetate-decarboxylating, non-hydrogen-oxidizing methane bacterium. Arch Microbiol. 1980 Jan;124(1):1–11. doi: 10.1007/BF00407022. [DOI] [PubMed] [Google Scholar]
- Zeikus J. G. The biology of methanogenic bacteria. Bacteriol Rev. 1977 Jun;41(2):514–541. doi: 10.1128/br.41.2.514-541.1977. [DOI] [PMC free article] [PubMed] [Google Scholar]
- el-Hag G. A., Miller T. B. Evaluation of whisky distillery by-products. VI. The reduction in digestibility of malt distiller's grains by fatty acids and the interaction with calcium and other reversal agents. J Sci Food Agric. 1972 Feb;23(2):247–258. doi: 10.1002/jsfa.2740230212. [DOI] [PubMed] [Google Scholar]