Elena Ariskina

Sphaerochaeta associata sp. nov., a spherical spirochaete isolated from cultures of Methanosarcina mazei JL01.

An anaerobic, saccharolytic bacterial strain designated GLS2T was isolated from aggregates of the psychrotolerant archaeon Methanosarcina mazei strain JL01 isolated from arctic permafrost. Bacterial cells were non-motile, spherical, ovoid and annular with diameter 0.2-4 μm. They were chemoorganoheterotrophs using a wide range of mono-, di- and trisaccharides as carbon and energy sources. The novel isolate required yeast extract and vitamins for growth. The bacteria exhibited resistance to a number of β-lactam antibiotics, rifampicin, streptomycin and vancomycin. Optimum growth was observed between 30 and 34 °C, at pH 6.8-7.5 and with 1-2 g NaCl l- 1. Isolate GLS2T was a strict anaerobe but it tolerated oxygen exposure. On the basis of 16S rRNA gene sequence similarity, strain GLS2T was shown to belong to the genus Sphaerochaeta within the family Spirochaetaceae. Its closest relatives were Sphaerochaeta globosa BuddyT (99.3 % 16S rRNA gene sequence similarity) and Sphaerochaeta pleomorpha GrapesT (95.4 % similarity). The G+C content of DNA was 47.2 mol%. The level of DNA-DNA hybridization between strains GLS2T and BuddyT was 34.7 ± 8.8 %. Major polar lipids were phosphoglycolipids, phospholipids and glycolipids; major fatty acids were C14 : 0, C16 : 0, C16 : 0 3-OH, C16 : 0 dimethyl acetal (DMA), C16 : 1n8 and C16 : 1 DMA; respiratory quinones were not detected. The results of DNA-DNA hybridization, physiological and biochemical tests demonstrated genotypic and phenotypic differentiation of strain GLS2T from the four species of the genus Sphaerochaeta with validly published names that allowed its separation into a new lineage at the species level. Strain GLS2T therefore represents a novel species, for which the name Sphaerochaeta associata sp. nov. is proposed, with the type strain GLS2T ( = DSM 26261T = VKM B-2742T).

Formation of bacterial nanocells

Existence of nanobacteria received increasing attention both in environmental microbiology/geomicro-biology and in medical microbiology. In order to study a production of nanoforms by typical bacterial cells. Effects of different physical factors were investigated. Treatment of bacterial cultures with microwave radiation, or culturing in field of electric current resulted in formation a few types of nanocells. The number and type of nanoforms were determined with type and dose of the treatment. The produced nanoforms were: i) globules, ii) clusters of the globules--probably produced by liaison, iii) nanocells coated with membrane. The viability of the globules is an object opened for doubts. The nanocells discovered multiplication and growth on solidified nutrient media. The authors suggest that formation of nanocells is a common response of bacteria to stress-actions produced by different agents.

Functions of non-crystal magnetosomes in bacteria

Intracellular non-crystal magnetosomes are presented in prokaryotes of different taxonomic and physiological groups. Formation of the internal magnetosomes is provoked with some external agents. The situation permits to discuss functions of the magnetosomes as responses to surroundings. A few possible functions are discussed. Hypothesis on oriented motion of bacteria in geomagnetic field suits well data on the linear intracellular distribution of the magnetosomes in some species. An additional hypothesis is oriented attraction of iron-containing compounds to magnetic bacteria. Independently, magnetosomes have a function of the intracellular iron storage. In strong magnetic field, magnetosomes stimulated lysis of bacteria. Sometimes the bacterial lysis was accompanied with production of nanocells.

Bacillus subtilis and Phenotypically Similar Strains Producing Hexaene Antibiotics

We studied metabolites synthesized by Bacillus subtilis strains, including the type strain of B. atrophaeus and phenotypically similar cultures. These metabolites were represented by polyene antibiotics with conjugated double bonds. Hexaenes from the strains under study inhibited the growth of phytopathogenic fungi Fusarium culmorum, F. sporotrichiella, F. oxysporum, Botrytis sorokiniana, Alternaria tenui, and Phytophthora infestans. The degree of growth inhibition depended on the test fungus.

Alkaliphilus namsaraevii sp. nov., an alkaliphilic iron- and sulfur-reducing bacterium isolated from a steppe soda lake

A novel alkaliphilic spore-forming bacterium was isolated from the benthic sediments of the highly mineralized steppe Lake Khilganta (Transbaikal Region, Russia). Cells of the strain, designated Х-07-2T, were straight to slightly curved rods, Gram-stain-positive and motile. Strain Х-07-2T grew in the pH range from 7.0 to 10.7 (optimum pH 9.6-10.3). Growth was observed at 25-47 °C (optimum 30 °C) and at an NaCl concentration from 5 to 150 g l-1 with an optimum at 40 g l-1. Strain Х-07-2T was a chemo-organoheterotroph able to reduce amorphous ferric hydroxide, Fe(III) citrate and elemental sulfur in the presence of yeast extract as the electron donor. It used tryptone, peptone and trypticase with Fe(III) citrate as the electron acceptor. The predominant fatty acids in cell walls were C16:1ω8, iso-C15:0, C14 : 0 3-OH and C16 : 0. The DNA G+C content was 32.6 mol%. 16S rRNA gene sequence analysis revealed that strain Х-07-2T was related most closely to members of the genus Alkaliphilus within the family Clostridiaceae. The closest relative was Alkaliphilus peptidifermentans Z-7036T (96.4 % similarity). On the basis of the genotypic, chemotaxonomic and phenotypic data, strain Х-07-2T represents a novel species in the genus Alkaliphilus, for which the name Alkaliphilus namsaraevii sp. nov. is proposed. The type strain is Х-07-2T (=VKM В-2746Т=DSM 26418Т).

Belliella buryatensis sp. nov., isolated from alkaline lake water

Two bacterial isolates from water of the alkaline brackish Lake Solenoe (Buryatia, Russia), 2C and 5CT, were characterized by using a polyphasic taxonomic approach. The strains were small, non-motile, Gram-stain-negative rods that formed small orange-red colonies on the surface of marine agar. Studies based on 16S rRNA gene sequences showed that the strains were related closely to Belliella pelovolcani CC-SAL-25T (98.7 % sequence similarity). The G+C content of the DNA was 38-40 mol%. DNA-DNA hybridization values between strains 2C and 5CT and B. pelovolcani CC-SAL-25T were 56-58 mol%. A menaquinone with seven isoprene units (MK-7) was the major respiratory quinone. The fatty acid profiles were slightly different from that of B. pelovolcani CC-SAL-25T. The novel strains could be distinguished from the phylogenetically closest species B. pelovolcani CC-SAL-25T based on matrix-assisted laser desorption ionization time-of-flight mass spectra of whole cells and a range of physiological and biochemical characteristics. The data obtained suggest that strains 2C and 5CT represent a novel species of the genus Belliella, for which the name Belliella buryatensis sp. nov. is proposed. The type strain is 5CT ( = VKM B-2724T = KCTC 32194T).

Draft Genome Sequence of “Cohnella kolymensis” B-2846

ABSTRACT A draft genome sequence of “Cohnella kolymensis” strain B-2846 was derived using IonTorrent sequencing technology. The size of the assembly and G+C content were in agreement with those of other species of this genus. Characterization of the genome of a novel species of Cohnella will assist in bacterial systematics.

Cohnella kolymensis sp. nov., a novel bacillus isolated from Siberian permafrost.

A facultative anaerobic, rod-shaped, endospore-forming and non-motile bacterium was isolated from permafrost sediment cores in the Kolyma lowland, Siberia, Russia. The permafrost isolate clustered with members of the genus Cohnella on the basis of 16S rRNA gene sequence analysis and showed the highest sequence similarity to Cohnella saccharovorans CJ22T (96.3 %), followed by Cohnella cellulosilytica FCN3-3T (96.0 %) and Cohnella panacarvi KCTC 13060T (96.0 %). The chemotaxonomic characteristics (quinone system, cellular fatty acids and polar lipid profile) of strain 20.16T were consistent with members of the genus Cohnella. The peptidoglycan diaminoacids included meso-diaminopimelic acid and a small amount of ll-diaminopimelic acid. The molar ratio and composition of major amino acids (meso-diaminopimelic acid, alanine, and glutamic acid) correspond to the peptydoglycan type A1γ. The estimated genome size of strain 20.16T is 4.34 Mb (lower than those in other Cohnella species). The genome has a G+C content of 50.5 mol% and encodes 4843 predicted genes, of these 4740 are protein-coding ones. The results of chemotaxonomic, physiological and biochemical characterization allowed clear differentiation of strain 20.16T from the closest Cohnella species. Based on data provided, a new species Cohnella kolymensis sp. nov. is proposed, with 20.16T (=VKM B-2846T=DSM 104983T) as the type strain.

Draft Genome Sequence of Modestobacter sp. strain VKM Ac-2676 from soil in the area of sharply continental climate

A draft genome sequence of a novel actinobacterium, Modestobacter sp. strain VKM Ac-2676, was derived using Ion Torrent sequencing technology. The genome size is 3.88 Mb with average G+C content of 73.40%. The genes encoding properties relevant to adaptability of this bacterium to a sharply continental climate zone were revealed.

Anoxynatronum buryatiense sp. nov., an anaerobic alkaliphilic bacterium from a low mineralization soda lake in Buryatia, Russia

An anaerobic alkaliphilic, proteolytic bacterium, strain Su22T, was isolated from the bottom sediment of the alkaline low mineralization lake Sulphatnoe (Selenginsky district, Buryatia, Russia). A comparative analysis of the 16S rRNA gene sequence revealed that this bacterium was closely related to Anoxynatronum sibiricum Z-7981T with a similarity of 98.1 %. Strain Su22T differed from A. sibiricum Z-7981T in its inability to use carbohydrates, peptone and amino acids as carbon sources. Strain Su22T grew over a temperature range of 20-40 °C with an optimum at 30 °C and within the pH range 7.4-11.0 with an optimum at pH 9.6. Sodium cations stimulated the growth of the strain considerably with an optimal concentration at 0.76-1.09 M. The whole-cell fatty acid profile included C16 : 1ω7c, C16 : 0 and C16 : 0 ALDE. The G+C content was 46.1 mol%. Based on the DNA-DNA hybridization level (53.2 %) and phenotypical differences between strains Su22T and Z-7981T, the new isolate is thus considered to represent a novel species, for which the name Anoxynatronumburyatiense sp. nov. is proposed. The type strain is Su22Т (=VKM B-2510T=CECT 8731T).