Affiliation:
1. Department of Microbiology, Montana State University, Bozeman, Montana 59717
Abstract
The fate of representative fermentation products (acetate, propionate, butyrate, lactate, and ethanol) in hot spring cyanobacterial mats was investigated. The major fate during incubations in the light was photoassimilation by filamentous bacteria resembling
Chloroflexus aurantiacus.
Some metabolism of all compounds occurred under dark aerobic conditions. Under dark anaerobic conditions, only lactate was oxidized extensively to carbon dioxide. Extended preincubation under dark anaerobic conditions did not enhance anaerobic catabolism of acetate, propionate, or ethanol. Acetogenesis of butyrate was suggested by the hydrogen sensitivity of butyrate conversion to acetate and by the enrichment of butyrate-degrading acetogenic bacteria. Accumulation of fermentation products which were not catabolized under dark anaerobic conditions revealed their importance. Acetate and propionate were the major fermentation products which accumulated in samples collected at temperatures ranging from 50 to 70�C. Other organic acids and alcohols accumulated to a much lesser extent. Fermentation occurred mainly in the top 4 mm of the mat. Exposure to light decreased the accumulation of acetate and presumably of other fermentation products. The importance of interspecies hydrogen transfer was investigated by comparing fermentation product accumulation at a 65�C site, with naturally high hydrogen levels, and a 55�C site, where active methanogenesis prevented significant hydrogen accumulation. There was a greater relative accumulation of reduced products, notably ethanol, in the 65�C mat.
Publisher
American Society for Microbiology
Subject
Ecology,Applied Microbiology and Biotechnology,Food Science,Biotechnology
Reference49 articles.
1. Awramik S. M. 1984. Ancient stromatolites and microbial mats p. 1-22. In Y. Cohen R. W. Castenholz and H. 0. Halvorson (ed.) Microbial mats: stromatolites. Alan R. Liss Inc. New York.
2. Microbial metabolism of acetate, propionate, and butyrate in anoxic sediment from the Colne Point Saltmarsh, Essex;Balba M. T.;U. K. J. Gen. Microbiol.,1982
3. Ecological studies of Chloroflexis, a gliding photosynthetic bacterium;Bauld J.;Arch. Mikrobiol.,1973
4. Thermobacteriodes acetoethylicus gen. nov. and sp. nov., a new chemoorganotrophic, anaerobic, thermophilic bacterium;Ben-Bassat A.;Arch. Microbiol.,1981
5. Propionate-degrading bacterium, Syntrophomonas wolinii sp. nov. gen. nov., from methanogenic ecosystems;Boone D. R.;Appl. Environ. Microbiol.,1980
Cited by
97 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献