S.N. Winogradsky Institute of Microbiology, Russian Academy of Sciences, Moscow 117312, Russia.
G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, Pushchino, Moscow region, 142292, Russia.
Int J Syst Evol Microbiol. 2013 Jun;63(Pt 6):2282-2289. doi: 10.1099/ijs.0.045658-0. Epub 2012 Nov 16.
An aerobic methanotrophic bacterium was isolated from an acidic (pH 3.9) Sphagnum peat bog in north-eastern Russia and designated strain MG30(T). Cells of this strain were Gram-negative, pale pink-pigmented, non-motile, thick rods that were covered by large polysaccharide capsules and contained an intracytoplasmic membrane system typical of type I methanotrophs. They possessed a particulate methane monooxygenase enzyme (pMMO) and utilized only methane and methanol. Carbon was assimilated via the ribulose-monophosphate pathway; nitrogen was fixed via an oxygen-sensitive nitrogenase. Strain MG30(T) was able to grow at a pH range of 3.8-7.3 (optimum pH 5.8-6.4) and at temperatures between 8 and 30 °C (optimum 20-25 °C). The major cellular fatty acids were C16:1ω5t, C16:1ω8c, C16:1ω7c and C14:0; the DNA G+C content was 48.5 mol%. The isolate belongs to the family Methylococcaceae of the class Gammaproteobacteria and displayed 94.7-96.9% 16S rRNA gene sequence similarity to members of the genus Methylomonas. However, strain MG30(T) differed from all taxonomically characterized members of this genus by the absence of motility, the ability to grow in acidic conditions and low DNA G+C content. Therefore, we propose to classify this strain as representing a novel, acid-tolerant species of the genus Methylomonas, Methylomonas paludis sp. nov. Strain MG30(T) (=DSM 24973(T)=VKM B-2745(T)) is the type strain.
一株好氧甲烷营养菌从俄罗斯东北部的酸性（pH3.9）泥炭沼泽中分离得到，并被命名为 MG30(T) 株。该菌株的细胞呈革兰氏阴性，浅粉红色，不运动，呈厚杆状，被大的多糖胶囊覆盖，并含有典型的 I 型甲烷营养菌的细胞质内膜系统。它们具有颗粒状甲烷单加氧酶（pMMO），仅利用甲烷和甲醇。碳通过核酮糖-1,5-二磷酸途径同化；氮通过氧敏感的固氮酶固定。MG30(T) 株可在 pH3.8-7.3 范围内（最佳 pH5.8-6.4）和 8-30°C 之间（最佳 20-25°C）生长。主要的细胞脂肪酸为 C16:1ω5t、C16:1ω8c、C16:1ω7c 和 C14:0；DNA G+C 含量为 48.5mol%。该分离株属于γ变形菌纲甲基球菌科，16S rRNA 基因序列相似性为 94.7-96.9%，与甲基单胞菌属的成员属于同一科。然而，MG30(T) 株与该属所有已分类的成员不同，表现在无运动性、能在酸性条件下生长和低 DNA G+C 含量。因此，我们建议将该菌株分类为代表一个新的、耐酸的甲基单胞菌属的种，即沼泽甲基单胞菌（Methylomonas paludis）sp. nov.。MG30(T) 株（=DSM 24973(T)=VKM B-2745(T)）是模式株。
