PDF(Pubmed)
Abstract：
Two thermophilic spore-forming sulfate-reducing strains, 435T and 781, were isolated from oil and gas reservoirs in Western Siberia (Russia) about 50 years ago. Both strains were found to be neutrophilic, chemoorganotrophic, anaerobic bacteria, growing at 45-70 °C (optimum, 55-60 °C) and with 0-4.5% (w/v) NaCl (optimum, 0.5-1% NaCl). The major fatty acids were iso-C15:0, iso-C17:0, C16:0, and C18:0. In sulfate-reducing conditions, the strains utilized H2/CO2, formate, lactate, pyruvate, malate, fumarate, succinate, methanol, ethanol, propanol, butanol, butyrate, valerate, and palmitate. In 2005, based on phenotypic characteristics and a 16S rRNA gene sequence analysis, the strains were described as \'Desulfotomaculum salinum\' sp. nov. However, this species was not validly published because the type strain was not deposited in two culture collections. In this study, a genomic analysis of strain 435T was carried out to determine its taxonomic affiliation. The genome size of strain 435T was 2.886 Mb with a 55.1% genomic G + C content. The average nucleotide identity and digital DNA-DNA hybridization values were highest between strain 435T and members of the genus Desulfofundulus, 78.7-93.3% and 25.0-52.2%, respectively; these values were below the species delineation cut-offs (<95-96% and <70%). The cumulative phenotypic and phylogenetic data indicate that two strains represent a novel species within the genus Desulfofundulus, for which the name Desulfofundulus salinus sp. nov. is proposed. The type strain is 435T (=VKM B-1492T = DSM 23196T). A genome analysis of strain 435T revealed the genes for dissimilatory sulfate reduction, autotrophic carbon fixation via the Wood-Ljungdahl pathway, hydrogen utilization, methanol and organic acids metabolism, and sporulation, which were confirmed by cultivation studies.
摘要：
两个嗜热孢子形成硫酸盐还原菌株，435T和781，大约50年前从西伯利亚西部（俄罗斯）的石油和天然气储层中分离出来。两种菌株都被发现是嗜中性粒细胞的，化学有机营养，厌氧细菌，在45-70°C生长(最佳，55-60°C）和0-4.5％（w/v）NaCl（最佳，0.5-1%NaCl)。主要脂肪酸是异C15:0、异C17:0、C16:0和C18:0。在硫酸盐还原条件下，菌株利用H2/CO2，甲酸，乳酸，丙酮酸,苹果酸,富马酸盐,琥珀酸盐,甲醇,乙醇,丙醇，丁醇,丁酸盐,戊酸盐，还有棕榈酸盐.2005年，基于表型特征和16S一rRNA基因序列分析，这些菌株被描述为“盐脱硫草带”。11月。然而,由于该类型菌株未存放在两个培养物中，因此该物种未有效发表。在这项研究中,对菌株435T进行了基因组分析以确定其分类隶属度。菌株435T的基因组大小为2.886Mb,基因组G+C含量为55.1%。435T菌株和Desulfofundulus属成员之间的平均核苷酸同一性和数字DNA-DNA杂交值最高，78.7-93.3%和25.0-52.2%，分别；这些值低于物种划分的截止值(<95-96%和<70%)。累积的表型和系统发育数据表明，两个菌株代表了Desulfofundulus属中的一个新物种，名称为Desulfofundulussalinussp。11月。是提议的。菌株类型为435T(=VKMB-1492T=DSM23196T)。菌株435T的基因组分析揭示了异化硫酸盐还原的基因，通过Wood-Ljungdahl途径进行自养碳固定，氢气利用，甲醇和有机酸的代谢，和孢子形成，种植研究证实了这一点。
