Non-Sulfate-Reducing, Syntrophic Bacteria Affiliated with Desulfotomaculum Cluster I Are Widely Distributed in Methanogenic Environments
| Autor: | Nobutada Kimura, Yan-Ling Qiu, Michael Wagner, Yoichi Kamagata, Philip Hugenholtz, Yuji Sekiguchi, Hideki Harada, Alexander Loy, Hiroyuki Imachi, Akiyoshi Ohashi |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
food.ingredient
Molecular Sequence Data Population Hydrogensulfite reductase Biology DNA Ribosomal Applied Microbiology and Biotechnology Microbial Ecology Microbiology food Syntrophy RNA Ribosomal 16S Hydrogensulfite Reductase education Ecosystem Phylogeny education.field_of_study Ecology Sulfates Pelotomaculum 16S ribosomal RNA biology.organism_classification Methanogen Culture Media Biochemistry Desulfotomaculum Peptococcaceae Propionates Methane Oxidation-Reduction Bacteria Hydrogen Food Science Biotechnology |
| Zdroj: | Applied and Environmental Microbiology. 72:2080-2091 |
| ISSN: | 1098-5336 0099-2240 |
| Popis: | The classical perception of members of the gram-positive Desulfotomaculum cluster I as sulfate-reducing bacteria was recently challenged by the isolation of new representatives lacking the ability for anaerobic sulfate respiration. For example, the two described syntrophic propionate-oxidizing species of the genus Pelotomaculum form the novel Desulfotomaculum subcluster Ih. In the present study, we applied a polyphasic approach by using cultivation-independent and culturing techniques in order to further characterize the occurrence, abundance, and physiological properties of subcluster Ih bacteria in low-sulfate, methanogenic environments. 16S rRNA (gene)-based cloning, quantitative fluorescence in situ hybridization, and real-time PCR analyses showed that the subcluster Ih population composed a considerable part of the Desulfotomaculum cluster I community in almost all samples examined. Additionally, five propionate-degrading syntrophic enrichments of subcluster Ih bacteria were successfully established, from one of which the new strain MGP was isolated in coculture with a hydrogenotrophic methanogen. None of the cultures analyzed, including previously described Pelotomaculum species and strain MGP, consumed sulfite, sulfate, or organosulfonates. In accordance with these phenotypic observations, a PCR-based screening for dsrAB (key genes of the sulfate respiration pathway encoding the alpha and beta subunits of the dissimilatory sulfite reductase) of all enrichments/(co)cultures was negative with one exception. Surprisingly, strain MGP contained dsrAB , which were transcribed in the presence and absence of sulfate. Based on these and previous findings, we hypothesize that members of Desulfotomaculum subcluster Ih have recently adopted a syntrophic lifestyle to thrive in low-sulfate, methanogenic environments and thus have lost their ancestral ability for dissimilatory sulfate/sulfite reduction. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|