Horonobe Research Institute for the Subsurface Environment (H-RISE) Northern Advancement Centre for Science and Technology (NOASTEC), Sakae-machi, Horonobe-cho, Teshio-gun, Hokkaido, Japan.
Horonobe Underground Research Center, Japan Atomic Energy Agency (JAEA), Hokushin 432-2, Horonobe-cho, Hokkaido 098-3224, Japan.
Int J Syst Evol Microbiol. 2021 Feb;71(2). doi: 10.1099/ijsem.0.004683.
A novel mesophilic sulfate-reducing bacterium, strain HN2, was isolated from groundwater sampled from the subsurface siliceous mudstone of the Wakkanai Formation located in Horonobe, Hokkaido, Japan. The bacterium was Gram-negative and vibrio-shaped, and its motility was conferred by a single polar flagellum. Cells had desulfoviridin. Catalase and oxidase activities were not detected. It grew in the temperature range of 25-40 °C (optimum, 35 °C) and pH range of 6.3-8.1 (optimum, pH 7.2-7.6). It used sulfate, thiosulfate, dimethyl sulfoxide, anthraquinone-2,6-disulfonate, Fe, and manganese oxide, but not elemental sulfur, nitrite, nitrate, or fumarate as electron acceptors. The strain showed weak growth with sulfite as the electron acceptor. Fermentative growth with pyruvate, lactate and cysteine was observed in the absence of sulfate, but not with malate or fumarate. NaCl was not required, but the strain tolerated up to 40 g l. Strain HN2 did not require vitamins. The major cellular fatty acids were iso-C (23.8 %), C 9 (18.4 %), C (15.0 %), C (14.5 %), and anteiso-C (10.1 %). The major respiratory quinone was menaquinone MK-6(H). The G+C content of the genomic DNA was 56.7 mol%. Based on 16S rRNA gene sequence analysis, the closest phylogenetic relative of strain HN2 is JS1 (97.0 %). Digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values of the strains HN2 and JS1 were 22.2 and 79.8 %, respectively. Based on the phenotypic and molecular genetic evidence, we propose a novel species, sp. nov. with the type strain HN2 (=DSM 101010=NBRC 112213).
一株新型嗜中温硫酸盐还原菌，HN2 株，从日本北海道泊村的早神保层地下硅质泥岩中的地下水样本中分离得到。该菌革兰氏阴性，呈弧状，通过单个极生鞭毛运动。细胞含有脱硫孤菌黄素。未检测到触酶和氧化酶活性。它在 25-40°C 的温度范围（最佳温度 35°C）和 6.3-8.1 的 pH 范围（最佳 pH 7.2-7.6）下生长。它以硫酸盐、硫代硫酸盐、二甲亚砜、蒽醌-2,6-二磺酸盐、Fe 和锰氧化物为电子受体，但不以元素硫、亚硝酸盐、硝酸盐或延胡索酸为电子受体。该菌株以亚硫酸盐作为电子受体时生长较弱。在没有硫酸盐的情况下，观察到与丙酮酸、乳酸和半胱氨酸的发酵生长，但没有与苹果酸或延胡索酸的发酵生长。菌株不需要 NaCl，但可耐受高达 40 g l。菌株 HN2 不需要维生素。主要细胞脂肪酸为 iso-C（23.8%）、C9（18.4%）、C（15.0%）、C（14.5%）和 anteiso-C（10.1%）。主要呼吸醌为 Menaquinone MK-6（H）。基因组 DNA 的 G+C 含量为 56.7 mol%。基于 16S rRNA 基因序列分析，HN2 株与 JS1 （97.0%）最为接近。菌株 HN2 和 JS1 的数字 DNA-DNA 杂交（dDDH）和平均核苷酸同一性（ANI）值分别为 22.2%和 79.8%。基于表型和分子遗传学证据，我们提出了一个新的物种， sp. nov.，其模式菌株为 HN2（=DSM 101010=NBRC 112213）。
