Methylorosula polaris gen. nov., sp. nov., an aerobic, facultatively methylotrophic psychrotolerant bacterium from tundra wetland soil

Abstract

Three strains of Gram-negative, aerobic, motile bacteria with bipolar flagella were isolated from acidic tundra wetland soils near the city of Vorkuta and from the Chukotka and Yugorsky Peninsulas and designated strains V-022T, Ch-022 and Ju-022. The cells were rod-shaped, 0.5–0.6 µm in width and 1.3–4.5 µm in length and reproduced by irregular fission. These bacteria were facultative methylotrophs that used methanol, methylamines and a wide range of other sources of carbon and energy such as sugars and polysaccharides, ethanol and amino acids. The isolates used the Calvin–Benson pathway for the assimilation of one-carbon compounds and were unable to fix nitrogen. The new strains were moderately acidophilic and psychrotolerant, capable of growth over a pH range of 4.0 to 7.8, with optimum growth at pH 5.5–6.0. Growth occurred between 4 and 30 °C (optimum 20–25 °C). The principal phospholipid fatty acid was C18 : 1ω7c. The DNA G+C content of strain V-022T was 65.2 mol%. Analysis of the 16S rRNA gene sequences revealed that all three isolates V-022T, Ch-022 and Yu-022 exhibited almost identical 16S rRNA gene sequences (99.9 % gene sequence similarity) and formed a new lineage within the class Alphaproteobacteria. The name Methylorosula polaris is suggested to accommodate this new genus and novel species with strain V-022T ( = DSM 22001T = VKM V-2485T) as the type strain of the type species.

The Family Beijerinckiaceae

“…In addition to these genes, the key genes of C 1 metabolism have also been widely used as phylogenetic and functional markers in a number of taxonomic and ecologic studies (Berestovskaya et al 2012;Dedysh et al 1998bDedysh et al , 2000Dedysh et al , 2001bDedysh et al , 2002Dedysh et al , 2004aDunfield et al 2003Dunfield et al , 2010Lau et al 2013;McDonald and Murrell 1997a, b;Vorob'ev et al 2009;Vorobev et al 2011).…”

“…Methylorosula (Berestovskaya et al 2012) is described as Gram-negative rods that are not capable of nitrogen fixation. Aerobic, facultative methylotrophic bacteria.…”

Emended description of the family Beijerinckiaceae and transfer of the genera Chelatococcus and Camelimonas to the family Chelatococcaceae fam. nov.

“…The former is present as only a minor fatty acid in most of the true, monophyletic Beijerinckiaceae. The DNA G+C contents range from 63.3 to 68.7 mol% (K€ ampfer et al, 2010;Jin et al, 2015), higher than the average for Beijerinckiaceae (54.7-65.2 mol%) (Kennedy, 2005;Vorobev et al, 2011;Berestovskaya et al, 2012).…”

“…By contrast, Methyloferula stellata grows only on methane and methanol (Vorobev et al, 2011). Finally, the genera Methylovirgula and Methylorosula accommodate facultatively methylotrophic bacteria (Vorob'ev et al, 2009;Berestovskaya et al, 2012). These methylotrophs assimilate C 1 compounds via the ribulose bisphosphate pathway.…”

“…Table 1. Major characteristics that distinguish currently described genera of the family Beijerinckiaceae Data for Beijerinckia are taken from Kennedy (2005) and Dedysh et al (2005a), data for Rhodoblastus from Imhoff (2001) and Kulichevskaya et al (2006), data for Methylocapsa from Dedysh et al (2002), Dedysh et al (2015) and Dunfield et al (2010), data for Methylocella from Dedysh et al (2000Dedysh et al ( , 2004Dedysh et al ( , 2005b, Dunfield et al (2003) and Dunfield & Dedysh (2014), data for Methyloferula from Vorobev et al (2011), data for Methylorosula from Berestovskaya et al (2012) *Methylocapsa acidiphila and M. palsarum do not utilize multicarbon compounds, while Methylocapsa aurea utilizes acetate. †In addition to these compounds utilized by all Methylocella species, Methylocella silvestris utilizes also propane, ethane, propanol, propanediol, acetone, methyl acetate, acetol, glycerol, propionate, gluconate and tetrahydrofuran.…”