title: Proteiniclasticum ruminis gen. nov., sp. nov., a strictly anaerobic proteolytic bacterium isolated from yak rumen.
abstract: Two strictly anaerobic, proteolytic bacterial strains, designated strain D3RC-2(T) and D3RC-3r, were isolated from a cellulose-degrading mixed culture enriched from yak rumen content. The strains were Gram-stain negative and non-spore-forming with cell sizes of 0.5-0.8 x 0.6-2.0 mum. The temperature range for growth was 24-46 degrees C (optimum 38-39 degrees C) and the pH range was between 5.6 and 8.7 (optimum 7.0-7.3). Both strains used soya peptone, tryptone, l-phenylalanine, l-leucine, l-methionine, l-serine, l-valine, l-threonine and l-histidine as carbon and nitrogen sources, but did not use any of the saccharides tested. The major fermentation products from PY medium were acetate, propionate and iso-butyrate. The DNA G+C contents of strains D3RC-2(T) and D3RC-3r were 41.0+/-0.1 mol% and 41.3+/-0.1 mol% (HPLC), respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two strains represented a new phyletic sublineage within the family Clostridiaceae, with <93.8 % 16S rRNA gene sequence similarity to recognized species. On the basis of the phenotypic, genotypic and physiological evidence, strains D3RC-2(T) and D3RC-3r are proposed as representing a novel species of a new genus, for which the name Proteiniclasticum ruminis gen. nov., sp. nov. is proposed. The type strain of the type species is D3RC-2(T) (=AS 1.5057(T)=JCM 14817(T)).
authors.affiliation: Graduate University, Chinese Academy of Sciences, Beijing 100049, PR China.|State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Kegui
authors.initials: K
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Lei
authors.initials: L
authors.lastname: Song
authors.affiliation: State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, PR China.
authors.forename: Xiuzhu
authors.initials: X
authors.lastname: Dong
mesh_terms: D000818:Animals; D001421:Bacteria, Anaerobic / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D002417:Cattle / Q000382:microbiology*; D002482:Cellulose / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012417:Rumen / Q000382:microbiology*; D012965:Sodium Chloride / Q000378:metabolism*
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D012336:RNA, Ribosomal, 16S; D012965:Sodium Chloride; D002482:Cellulose