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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.

Gram-negative, aerobic, chemo-organotrophic and bacteriochlorophyll a-containing bacterial strains, KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152, were isolated from the thalli of Cladonia arbuscula and Cladonia stellaris lichens. Cells from the strains were coccoid and reproduced by binary division. They were motile at the early stages of growth and utilized sugars and alcohols. All strains were psychrophilic and acidophilic, capable of growth between pH 3.5 and 7.5 (optimum, pH 5.5), and at 4–30 °C (optimum, 10–15 °C). The major fatty acids were C18 : 1  ω7c and C18 : 0; the lipids were phosphatidylcholines, phosphatidylethanolamines, phosphatidic acids, phosphatidylglycerol, glycolipids, diphosphatidylglycerol and polar lipids with an unknown structure. The quinone was Q-10. The DNA G+C content was 67.8 mol%. Comparative 16S rRNA gene analysis together with other data, supported that the strains, KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152 belonged to the same species. Whole genome analysis of the strain KEBCLARHB70RT and average amino acid identity values confirmed its distinctive phylogenetic position within the family Acetobacteraceae . Phenotypic, ecological and genomic characteristics distinguished strains KEBCLARHB70RT, KAMCLST3051 and KAMCLST3152 from all genera in the family Acetobacteraceae . Therefore, we propose a novel genus and a novel species, Lichenicoccus roseus gen. nov., sp. nov., for these novel Acetobacteraceae members. Strain KEBCLARHB70RT (=KCTC 72321T=VKM B-3305T) has been designated as the type strain.

The sensitivity of anaerobic ammonium-oxidizing (anammox) bacteria to environmental fluctuations is a frequent cause of reactor malfunctions. It was hypothesized that the addition of formate and folate would have a stimulating effect on anammox bacteria, which in turn would lead to the stability of the anammox process under conditions of a sharp increase in ammonium load, i.e., it helps overcome a stress factor. The effect of formate and folate was investigated using a setup consisting of three parallel sequencing batch reactors equipped with a carrier. Two runs of the reactors were performed. The composition of the microbial community was studied by the 16S rRNA gene profiling and metagenomic analysis. Among anammox bacteria, Ca. “Brocadia” spp. dominated during the first run. A stimulatory effect of folate on the daily nitrogen removal rate (dN) was identified. The addition of formate led to progress in dissimilatory nitrate reduction and stimulated the growth of Ca. “Jettenia” spp. The spatial separation of two anammox species was observed in the formate reactor: Ca. “Brocadia” occupied the carrier and Ca. “Jettenia”—the walls of the reactors. Biomass storage at low temperature without feeding led to an interspecies shift in anammox bacteria in favor of Ca. “Jettenia.” During the second run, a domination of Ca. “Jettenia” spp. was recorded along with a stimulating effect of formate, and there was no effect of folate on dN. A comparative genome analysis revealed the patterns suggesting different strategies used by Ca. “Brocadia” and Ca. “Jettenia” spp. to cope with environmental changes.

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