Ueki Atsuko, Abe Kunihiro, Kaku Nobuo, Watanabe Kazuya, Ueki Katsuji
Faculty of Agriculture, Yamagata University, Wakaba-machi 1-23, Tsuruoka 997-8555, Japan.
Int J Syst Evol Microbiol. 2008 Feb;58(Pt 2):346-52. doi: 10.1099/ijs.0.65486-0.
Two strictly anaerobic bacterial strains (SV434(T) and S562) were isolated from rice-straw residue in a methanogenic reactor treating waste from cattle farms in Japan. They had identical 16S rRNA gene sequences and showed almost the same phenotypic properties. The cells of both strains were Gram-negative, non-motile, non-spore-forming rods; extraordinarily long rods often occurred. Remarkable stimulation of growth occurred with the addition of haemin and cobalamin (vitamin B(12)) to the medium. The supplementary cobalamin and haemin could be replaced if autoclaved and clarified sludge fluid obtained from the reactor was added. Both strains utilized a range of growth substrates, including arabinose, fructose, galactose, glucose, mannose, cellobiose, maltose, glycogen, starch, dextrin, amygdalin, lactate and pyruvate. Both strains produced acetate and propionate with a small amount of succinate from these substrates in the presence of haemin and cobalamin. Both strains were slightly alkaliphilic, having a pH optimum at about 7.9. The temperature range for growth was 5-35 degrees C, the optimum being 30 degrees C. The NaCl concentration range for growth was 0-4 % (w/v). Catalase activity was not detected in cells cultivated without haemin, whereas cells cultivated with haemin usually had the enzyme activity. Oxidase and nitrate-reducing activities were not detected. Aesculin was hydrolysed, but gelatin was not hydrolysed. Both strains were sensitive to bile acids. The major cellular fatty acids of both strains were anteiso-C(15 : 0) and iso-C(15 : 0). Menaquinones MK-8(H(0)) and MK-9(H(0)) were the major respiratory quinones and the genomic DNA G+C contents were 46.2-47.5 mol%. A phylogenetic analysis based on 16S rRNA gene sequences placed both strains in the phylum Bacteroidetes. Bacteroides coprosuis (isolated from swine-manure storage pits) was the species most closely related to both strains (95.9 % 16S rRNA gene sequence similarity to the type strain). On the basis of the phylogenetic, physiological and chemotaxonomic analyses, strains SV434(T) and S562 represent a novel species of the genus Bacteroides, for which the name Bacteroides propionicifaciens sp. nov. is proposed. The type strain is SV434(T) (=JCM 14649(T) =DSM 19291(T)).
从日本一家处理养牛场废弃物的产甲烷反应器中的稻草残渣中分离出了两株严格厌氧的细菌菌株（SV434(T) 和 S562）。它们具有相同的 16S rRNA 基因序列，并且表现出几乎相同的表型特征。两株菌株的细胞均为革兰氏阴性、无运动性、不形成芽孢的杆菌；经常出现异常长的杆菌。向培养基中添加血红素和钴胺素（维生素 B12）后，生长受到显著刺激。如果添加从反应器中获得的经高压灭菌并澄清的污泥液，则可以替代补充的钴胺素和血红素。两株菌株都利用多种生长底物，包括阿拉伯糖、果糖、半乳糖、葡萄糖、甘露糖、纤维二糖、麦芽糖、糖原、淀粉、糊精、苦杏仁苷、乳酸和丙酮酸。在血红素和钴胺素存在的情况下，两株菌株从这些底物中产生乙酸盐和丙酸盐以及少量琥珀酸盐。两株菌株均略微嗜碱，最适 pH 约为 7.9。生长的温度范围是 5 - 35℃，最适温度为 30℃。生长的 NaCl 浓度范围是 0 - 4%（w/v）。在没有血红素培养的细胞中未检测到过氧化氢酶活性，而用血红素培养的细胞通常具有该酶活性。未检测到氧化酶和硝酸盐还原活性。七叶苷被水解，但明胶未被水解。两株菌株均对胆汁酸敏感。两株菌株的主要细胞脂肪酸是anteiso-C(15 : 0) 和 iso-C(15 : 0)。甲基萘醌 MK-8(H(0)) 和 MK-9(H(0)) 是主要的呼吸醌，基因组 DNA 的 G+C 含量为 46.2 - 47.5 mol%。基于 16S rRNA 基因序列的系统发育分析将两株菌株置于拟杆菌门。粪拟杆菌（从猪粪储存坑中分离）是与两株菌株关系最密切的物种（与模式菌株的 16S rRNA 基因序列相似性为 95.9%）。基于系统发育、生理和化学分类分析，菌株 SV434(T) 和 S562 代表拟杆菌属的一个新物种，为此提出名称丙酸拟杆菌（Bacteroides propionicifaciens sp. nov.）。模式菌株是 SV434(T)（=JCM 14649(T) =DSM 19291(T)）。
