A novel gammaproteobacterial methanotroph; strain FWC3 was isolated from a tropical freshwater wetland sample collected near a beach in Western India. Strain FWC3 forms flesh pink/peach colored colonies, is non-motile, and the cells are present as diplococci, triads, tetracocci and aggregates. Strain FWC3 grows only on methane and methanol. As the 16S rRNA gene of strain FWC3 showed low similarities with other Type I methanotrophs (less than 94.3%), it was further investigated for its novelty and characterisation by a polyphasic approach. ANI indices and DDH values deduced from the draft genome of strain FWC3 (SEYW00000000.1) with the other nearest type strains (Methylocaldum marinum S8T and Methylococcus capsulatus BathT) were ~ 70% and ~ 15%, respectively. The low level similarities indicated that strain FWC3 can belong to a new genus and species. Additionally, strain FWC3 showed a unique fatty acid profile with the dominance of C16:1 ω7 and ω6c, C16:0 and C16:1 ω9c. During the characterisation of strain FWC3, a morphologically similar methanotroph, strain C50C1 was described (Ghashghavi et al. in mSphere 4:e00631-18, 2019) and named as 'Methylotetracoccus oryzae'. We found that strain FWC3 and strain C50C1 belonged to the same genus but could belong to different species based on the ANI indices and dDDH values (~ 94% and ~ 55%, respectively). However, strain C50C1 has not been deposited in two culture collections and not been validly described. Also, the 16S rRNA gene of strain C50C1 is neither available on the database nor can it be retrieved from the genome assembly. Based on the polyphasic characterisation and comparison to the other type strains of Methylococcaceae, we propose strain FWC3 (= JCM 33786T, = KCTC 72733T, = MCC 4198T) to be the type strain of a novel genus and species, for which the name Methylolobus aquaticus is proposed. Strain C50C1 (Ghashghavi et al. 2019) could represent another species ('Methylolobus oryzae').

中文翻译：

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一种新型的I型甲烷营养菌甲基水生细菌。十一月 sp。十一月 隔离于热带湿地。

一种新型的γ-蛋白细菌甲烷营养菌；从印度西部海滩附近收集的热带淡水湿地样品中分离出FWC3菌株。菌株FWC3形成肉粉色/桃色菌落，不活动，细胞以双球菌，三联体，四球菌和聚集体形式存在。FWC3菌株仅在甲烷和甲醇上生长。由于FWC3菌株的16S rRNA基因与其他I型甲烷营养菌（低于94.3％）的相似性较低，因此通过多相方法对其新颖性和特征进行了进一步研究。从菌株FWC3（SEYW00000000.1）的基因组草图中推论出的ANI指数和DDH值分别为〜70％和〜15％，其他最接近类型的菌株（海藻Methylocaldum marinum S8T和荚膜甲基球菌BathT）。低水平相似性表明菌株FWC3可以属于新属和新种。另外，菌株FWC3显示出独特的脂肪酸谱，其优势为C16：1ω7和ω6c，C16：0和C16：1ω9c。在表征FWC3菌株的过程中，描述了一种形态相似的甲烷营养菌C50C1菌株（Ghashghavi等人在mSphere 4：e00631-18，2019），并命名为'Methylotetracoccus oryzae'。我们发现菌株FWC3和菌株C50C1属于同一属，但基于ANI指数和dDDH值（分别为〜94％和〜55％），它们可能属于不同的物种。但是，菌株C50C1尚未保存在两个培养物中，因此没有得到有效的描述。同样，菌株C50C1的16S rRNA基因既在数据库中不可用，也不能从基因组装配中检索。基于多相特征并将其与其他甲基球菌科菌株进行比较，我们提出菌株FWC3（= JCM 33786T，= KCTC 72733T，= MCC 4198T）是一种新的属和种的菌株，其名称为Methylolobus aquaticus被提议。菌株C50C1（Ghashghavi et al.2019）可能代表另一个物种（'Methylolobus oryzae'）。