Draft Genome Sequence of the Anoxygenic Phototrophic Bacterium Rhodoferax sp. Strain U11-2br, Isolated from a Mountain Lake on the Ulagan Plateau.

We report the draft genome sequence of an anoxygenic phototrophic bacterium, Rhodoferax sp. strain U11-2br, which was isolated from a freshwater mountain lake on the Ulagan Plateau (Altai, Russia). The assembly contains 4,514,979 bp, with a GC content of 59.9%.

Draft Genome Sequence of the Anoxygenic Phototrophic Bacterium Rhodomicrobium sp. Strain Az07, Isolated from a Brackish Canal.

Rhodomicrobium sp. strain Az07 was isolated from a brackish canal. The organism is more halotolerant than previously described species of the genus Rhodomicrobium. The Illumina MiSeq system was used to sequence the genome of the isolated strain. The assembly contains 3,291,400 bp, 106 contigs, and a GC content of 62.7%.

[The structure of phototrophic communities of soda lakes of the southeastern Transbaikal region].

The structure of benthic phototrophic communities of 24 soda lakes of the southeastern Transbaikal Region was studied. The physicochemical properties of the lakes were determined. The results of the cell count of anoxygenic phototrophic bacteria (APB) belonging to various groups are presented. The influence of salinity on the structure of APB communities was investigated. The APB reaction to environmental conditions was determined. Massive development of phototrophic microorganisms in the form of mats and films was observed in the majority of the investigated lakes. The APB communities were characterized by a wide diversity of species and evenness of species composition. Purple sulfur bacteria of the families Ectothiorhodospiraceae and Chromatiaceae were predominant. Purple nonsulfur bacteria of the family Rhodobacteraceae, green filamentous bacteria Oscillochloris sp., and heliobacteria were also detected. According to preliminary data, no less than 15 species of APB occur in the studied lakes. Among them, three novel genera and four species have already been described. Identification of other isolates is still in progress. The lakes make an almost continuous series of fresh, brackish, and saline water bodies, varying in their degree of mineralization. It was demonstrated that the structure of APB communities was unaffected by salinity ranging from 5 to 40 g/l. At salt concentrations of lower than 5 g/l, the level of water mineralization became a limiting factor. Experiments with the isolated cultures showed that the APB were obligately dependent on the presence of carbonate ions in the medium. They were haloalkalitolerant or haloalkaliphilic. Thus, they are well adapted to the conditions of soda lakes with a high mineralization. It was demonstrated that soda lakes of the southeastern Transbaikal Region represent a special type of habitat which harbors a peculiar autochthonous microflora and differs from both highly mineralized soda lakes and shallow saline water bodies of the sea origin.

[The role of alpha-amylase of symbiotic microflora in digestion by lower cestodes and their fish hosts].

The symbiotic microflora associated with the digestive-transport surfaces of the pike intestine and the parasitic cestodes Triaenophorus nodulosus proved capable of the initial stages of carbohydrate hydrolysis mediated by alpha-amylase. The products of hydrolysis by alpha-amylase can be used by both the host and the parasite, which decreases energy expenditures of the macroorganisms. The levels of the bacterial alpha-amylase activity are comparable to those of the analogous enzyme absorbed on the mucosa of the intestine and on the cestode tegument, which indicates a considerable contribution of enzymes of the symbiotic microflora to digestion by the host and the parasite. Apparently, this contribution depends on the fish diet.