Methylomonas paludis sp. nov., the first acidtolerant member of the genus Methylomonas, from an acidic wetland et al., 2012). Members of these species are Gram-negative, rod-shaped or coccobacillary cells that produce pink or orange carotenoid pigments, are motile by means of a single flagellum, and grow between pH 5.0 and 9.0, with an optimum at pH 6.5-7.0.Representatives of the genus Methylomonas are especially abundant in various semi-neutral or slightly alkaline environments, such as rice paddies, water-saturated soils, volcanic areas, fresh and marine waters, lakes and sediments (Auman et al., 2000;Auman & Lidstrom, 2002; Hutchens et al., 2004; Lin et al., 2004; Lüke et al., 2010;Dianou et al., 2012). Recently, however, evidence for the presence of Methylomonas-like bacteria in acidic boreal forest soils and Sphagnum-dominated wetlands was obtained in several cultivation-independent studies (Morris et al., 2002; JaatinenAbbreviations: ICMs, intracytoplasmic membranes; MMO, methane monooxygenase; PFK, 6-phosphofructokinase; PLFA, polar lipid fatty acid; RuBP, ribulose-1,5-bisphosphate; RuMP, ribulose monophosphate.The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequence and the partial sequences of the pmoA, mxaF and nifH genes of strain MG30 T are HE801216-HE801219, respectively.