Viulu Samson, Nakamura Kohei, Kojima Akihiro, Yoshiyasu Yuki, Saitou Sakiko, Takamizawa Kazuhiro
United Graduate School of Agricultural Science, Gifu University.
J Gen Appl Microbiol. 2013;59(5):325-34. doi: 10.2323/jgam.59.325.
An ethanol-utilizing Fe(III)-reducing bacterial strain, OSK2A(T), was isolated from a lotus field in Aichi, Japan. Phylogenetic analysis of the 16S rRNA gene sequences of OSK2A(T) and related strains placed it within Geobacter sulfurreducens PCA(T). Strain OSK2A(T) was shown to be a Gram-negative, motile, rod-shaped bacterium, strictly anaerobic, 0.76-1.65 µm long and 0.28-0.45 μm wide. Its growth occurred at 20-40℃, pH 6.0-8.1, and it tolerated up to 1% NaCl. The G+C content of the genomic DNA was 61.2 mol% and DNA-DNA hybridization value with Geobacter sulfurreducens PCA(T) was 60.7%. The major respiratory quinone was MK-8. The major fatty acids were 16：1 ω7c, 16：0, 14：0, 15：0 iso, 16：1 ω5c, and 18：1 ω7c. Strain OSK2A(T) could utilize H2, ethanol, acetate, lactate, pyruvate, and formate as substrates with Fe(III)-citrate as electron acceptor. Amorphous Fe(III) hydroxide, Fe(III)-NTA, fumarate, malate, and elemental sulfur were utilized as electron acceptors with either acetate or ethanol as substrates. Results obtained from physiological, DNA-DNA hybridization, and chemotaxonomic tests support genotypic and phenotypic differentiation of strain OSK2A(T) from its closest relative. The isolate is assigned as a novel subspecies with the name Geobacter sulfurreducens subsp. ethanolicus, subsp. nov. (type strain OSK2A(T)=DSMZ 26126(T)=JCM 18752(T)).
从日本爱知县的一个莲田中分离出了一株利用乙醇的铁（III）还原细菌菌株OSK2A(T)。对OSK2A(T)及相关菌株的16S rRNA基因序列进行系统发育分析，结果表明它属于硫还原地杆菌PCA(T)。菌株OSK2A(T)为革兰氏阴性、具运动性、杆状细菌，严格厌氧，长0.76 - 1.65 µm，宽0.28 - 0.45 µm。其生长温度为20 - 40℃，pH值为6.0 - 8.1，能耐受高达1%的NaCl。基因组DNA的G + C含量为61.2 mol%，与硫还原地杆菌PCA(T)的DNA - DNA杂交值为60.7%。主要呼吸醌为MK - 8。主要脂肪酸为16：1 ω7c、16：0、14：0、15：0 iso、16：1 ω5c和18：1 ω7c。菌株OSK2A(T)能够利用氢气、乙醇、乙酸盐、乳酸盐、丙酮酸盐和甲酸盐作为底物，以柠檬酸铁（III）作为电子受体。无定形氢氧化铁（III）、铁（III） - NTA、富马酸盐、苹果酸盐和元素硫可作为电子受体，以乙酸盐或乙醇作为底物。生理、DNA - DNA杂交和化学分类学测试结果支持菌株OSK2A(T)与其最接近的亲缘种在基因型和表型上的分化。该分离株被指定为一个新亚种，命名为硫还原地杆菌乙醇利用亚种（Geobacter sulfurreducens subsp. ethanolicus），新亚种（模式菌株OSK2A(T)=DSMZ 26126(T)=JCM 18752(T)）。
