Department of Microbiology, Faculty of Biological and Veterinary Sciences, Nicolaus Copernicus University, Lwowska 1, 87 100 Torun, Poland.
School of Natural and Environmental Sciences, Ridley Building, Newcastle University, Newcastle upon Tyne NE1 7RU, United Kingdom.
Syst Appl Microbiol. 2020 Jan;43(1):126051. doi: 10.1016/j.syapm.2019.126051. Epub 2019 Dec 23.
A polyphasic study was undertaken to establish the taxonomic status of three Modestobacter strains isolated from a high altitude Atacama Desert soil. The isolates, strains 1G6, 1G14 and 1G50, showed chemotaxonomic and morphological properties characteristic of members of the genus Modestobacter. The peptidoglycan contained meso-diaminopimelic acid, the whole cell sugars were glucose and ribose (diagnostic sugars) and arabinose, the predominant menaquinone was MK-9(H), polar lipid patterns contained diphosphatidylglycerol, glycophosphatidylinositol, phosphatidylethanolamine (diagnostic component), phosphatidylglycerol and phosphatidylinositol while whole cellular fatty acid profiles consisted of complex mixtures of saturated, unsaturated iso- and anteiso-components. The isolates were shown to have different BOX-PCR fingerprint and physiological profiles. They formed a distinct phyletic line in Modestobacter 16S rRNA gene trees, were most closely related to the type strain of Modestobacter italicus (99.9 % similarity) but were distinguished from this and other closely related Modestobacter type strains using a combination of phenotypic properties. Average nucleotide identity and digital DNA:DNA hybridization similarities between the draft genome sequences of isolate 1G6 and M. italicus BC 501 were 90.9 % and 42.3 %, respectively, indicating that they belong to different species. Based on these phenotypic and genotypic data it is proposed that the isolates be assigned to a novel species in the genus Modestobacter, namely as Modestobacter excelsi with isolate 1G6 (=DSM 107535 =PCM 3004) as the type strain. Analysis of the whole genome sequence of M. excelsi 1G6 (genome size of 5.26 Mb) showed the presence of genes and gene clusters that encode for properties that are in tune with its adaptation to extreme environmental conditions that prevail in the Atacama Desert biome.
进行了多相研究，以确定从高海拔阿塔卡马沙漠土壤中分离出的三株适度杆菌菌株的分类地位。这些分离株，菌株 1G6、1G14 和 1G50，表现出化学分类学和形态学特性，这些特性是适度杆菌属成员的特征。肽聚糖含有 meso-二氨基庚二酸，全细胞糖是葡萄糖和核糖（诊断糖）和阿拉伯糖，主要的menaquinone 是 MK-9(H)，极性脂模式含有双磷脂酰甘油、糖磷脂酰肌醇、磷脂酰乙醇胺（诊断成分）、磷脂酰甘油和磷脂酰肌醇，而全细胞脂肪酸图谱则由饱和、不饱和异和前异成分的复杂混合物组成。这些分离株表现出不同的 BOX-PCR 指纹图谱和生理特征。它们在适度杆菌 16S rRNA 基因树中形成一个独特的进化枝，与模式种意大利适度杆菌（99.9%相似）最为密切相关，但与该种和其他密切相关的适度杆菌模式种通过表型特性的组合加以区分。1G6 分离株和 M.italicus BC 501 的基因组草图序列之间的平均核苷酸同一性和数字 DNA:DNA 杂交相似性分别为 90.9%和 42.3%，表明它们属于不同的种。基于这些表型和基因型数据，建议将这些分离株分配到适度杆菌属中的一个新种，即卓越适度杆菌，其 1G6 分离株（=DSM 107535 =PCM 3004）为模式株。卓越适度杆菌 1G6 的全基因组序列分析（基因组大小为 5.26 Mb）表明，存在编码适应阿塔卡马沙漠生物群落中普遍存在的极端环境条件的特性的基因和基因簇。
