Abstract
The ultrastructure of bacterial granules that were maintained in an upflow anaerobic sludge bed and filter reactor was examined. The reactor was fed a sucrose medium, and it was operated at 35 degrees C. Scanning and transmission electron microscopy revealed that the granular aggregates were three-layered structures. The exterior layer of the granule contained a very heterogeneous population that included rods, cocci, and filaments of various sizes. The middle layer consisted of a slightly less heterogeneous population than the exterior layer. A more ordered arrangement, made up predominantly of bacterial rods, was evident in this second layer. The third layer formed the internal core of the granules. It consisted of large numbers of Methanothrix-like cells. Large cavities, indicative of vigorous gas production, were evident in the third layer. On the basis of these ultrastructural results, a model that presents a possible explanation of granule development is offered.
Full text
PDF
Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Boone D. R., Bryant M. P. Propionate-Degrading Bacterium, Syntrophobacter wolinii sp. nov. gen. nov., from Methanogenic Ecosystems. Appl Environ Microbiol. 1980 Sep;40(3):626–632. doi: 10.1128/aem.40.3.626-632.1980. [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]
- Costerton J. W., Irvin R. T., Cheng K. J. The bacterial glycocalyx in nature and disease. Annu Rev Microbiol. 1981;35:299–324. doi: 10.1146/annurev.mi.35.100181.001503. [DOI] [PubMed] [Google Scholar]
- Dwyer D. F., Weeg-Aerssens E., Shelton D. R., Tiedje J. M. Bioenergetic conditions of butyrate metabolism by a syntrophic, anaerobic bacterium in coculture with hydrogen-oxidizing methanogenic and sulfidogenic bacteria. Appl Environ Microbiol. 1988 Jun;54(6):1354–1359. doi: 10.1128/aem.54.6.1354-1359.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Genthner B. R., Price W. A., Pritchard P. H. Characterization of anaerobic dechlorinating consortia derived from aquatic sediments. Appl Environ Microbiol. 1989 Jun;55(6):1472–1476. doi: 10.1128/aem.55.6.1472-1476.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Henrici A. T. Studies of Freshwater Bacteria: I. A Direct Microscopic Technique. J Bacteriol. 1933 Mar;25(3):277–287. doi: 10.1128/jb.25.3.277-287.1933. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jones W. J., Guyot J. P., Wolfe R. S. Methanogenesis from sucrose by defined immobilized consortia. Appl Environ Microbiol. 1984 Jan;47(1):1–6. doi: 10.1128/aem.47.1.1-6.1984. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Mah R. A., Ward D. M., Baresi L., Glass T. L. Biogenesis of methane. Annu Rev Microbiol. 1977;31:309–341. doi: 10.1146/annurev.mi.31.100177.001521. [DOI] [PubMed] [Google Scholar]
- McInerney M. J., Bryant M. P., Hespell R. B., Costerton J. W. Syntrophomonas wolfei gen. nov. sp. nov., an Anaerobic, Syntrophic, Fatty Acid-Oxidizing Bacterium. Appl Environ Microbiol. 1981 Apr;41(4):1029–1039. doi: 10.1128/aem.41.4.1029-1039.1981. [DOI] [PMC free article] [PubMed] [Google Scholar]
- REYNOLDS E. S. The use of lead citrate at high pH as an electron-opaque stain in electron microscopy. J Cell Biol. 1963 Apr;17:208–212. doi: 10.1083/jcb.17.1.208. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zeikus J. G., Bowen V. G. Comparative ultrastructure of methanogenic bacteria. Can J Microbiol. 1975 Feb;21(2):121–129. doi: 10.1139/m75-019. [DOI] [PubMed] [Google Scholar]