Trophic interaction of the aerotolerant anaerobe Clostridium intestinale and the acetogen Sporomusa rhizae sp. nov. isolated from roots of the black needlerush Juncus roemerianus

• Published in: Microbiology (Society for General Microbiology) 2006-04, Vol.152 (4), p.1209-1219
• Main Authors: Gossner, Anita S, Kusel, Kirsten, Schulz, Daria, Trenz, Sonja, Acker, George, Lovell, Charles R, Drake, Harold L
• Format: Article
• Language: English
• Subjects: Acetic Acid - metabolism; Bacteriology; Biological and medical sciences; Butyrates - metabolism; Carbohydrate Metabolism; Clostridium; Clostridium - classification; Clostridium - isolation & purification; Clostridium - metabolism; Clostridium intestinale; DNA, Bacterial - chemistry; DNA, Bacterial - genetics; DNA, Ribosomal - chemistry; DNA, Ribosomal - genetics; Fermentation; Formates - metabolism; Fundamental and applied biological sciences. Psychology; Genetics; Hydrogen - metabolism; Juncus; Juncus roemerianus; Lactic Acid - metabolism; Magnoliopsida - microbiology; Microbiology; Microscopy, Electron, Transmission; Molecular Sequence Data; Oxygen Consumption; Pathogenicity, virulence, toxins, bacteriocins, pyrogens, host-bacteria relations, miscellaneous strains; Phylogeny; Plant Roots - microbiology; RNA, Ribosomal, 16S - genetics; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid; Sporomusa; Sporomusa rhizae; Veillonellaceae - classification; Veillonellaceae - isolation & purification; Veillonellaceae - metabolism
• ISSN: 1350-0872; 1465-2080
• DOI: 10.1099/mic.0.28725-0

1 Department of Ecological Microbiology, University of Bayreuth, 95440 Bayreuth, Germany 2 Electron Microscopy Laboratory, University of Bayreuth, 95440 Bayreuth, Germany 3 Department of Biological Sciences, University of South Carolina, Columbus, SC 29208, USA Correspondence Harold L. Drake HLD{at}Uni-Bayreuth.De Acetogens were enumerated from root homogenates of the black needlerush Juncus roemerianus obtained from a nearly pristine salt marsh. An isolated colony, ST1, yielded acetogenic activity and was initially thought to be a pure culture; however, ST1 was subsequently found to be composed of an aerotolerant fermentative anaerobe (RC) and an acetogen (RS T ) ( T indicates type strain). The two spore-forming mesophiles were separated by selective cultivation under conditions favouring the growth of either RC or RS T . The 16S rRNA gene sequence of RC was 99 % similar to that of Clostridium intestinale , indicating that RC was a new isolate of this clostridial species. The rRNA gene sequence most similar to that of RS T was only 96 % similar to that of RS T and was from a species of the acetogenic genus Sporomusa , indicating that RS T was a new sporomusal species; the name Sporomusa rhizae sp. nov. is proposed. RC grew at the expense of saccharides. H 2 -forming butyrate fermentation was the primary catabolism utilized by RC under anoxic conditions, while homolactate fermentation was the primary catabolism under oxic conditions. RC consumed O 2 and tolerated 20 % O 2 in the headspace of shaken broth cultures. In contrast, RS T was acetogenic, utilized H 2 , lactate and formate, did not utilize saccharides, and could not tolerate high concentrations of O 2 . RS T grew by trophic interaction with RC on saccharides via the uptake of H 2 , and, to a lesser extent, lactate and formate produced by RC. Co-cultures of the two organisms yielded high amounts of acetate. These results indicate that (i) previously uncharacterized species of Sporomusa are associated with Juncus roots and (ii) trophic links to O 2 -consuming aerotolerant anaerobes might contribute to the in situ activities and survival strategies of acetogens in salt marsh rhizospheres, a habitat subject to gradients of plant-derived O 2 . Abbreviations: MPN, most probable number The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of RC (1480 bp sequenced) and RS T (1387 bp sequenced) are AM158323 and AM158322 , respectively. Present address: Limnology Research Group, Institute