E. B. Kudryashova

Anionic polymers of the cell wall of Bacillus subtilis subsp. subtilis VKM B-501T

Teichoic acid and disaccharide-1-phosphate polymer were identified in the cell walls of Bacillus subtilis subsp. subtilis VKM B-501T. The teichoic acid represents 1,3-poly(glycerol phosphate) 80% substituted by α-D-glucopyranose residues at O-2 of glycerol. The linear repeating unit of disaccharide-1-phosphate polymer contains the residues of β-D-glucopyranose, N-acetyl-α-D-galactosamine, and phosphate and has the following structure: -6)-β-D-Glcp-(1→3)-α-D-GalpNAc-(1-P-. The structures of two anionic polymers were determined by chemical and NMR-spectroscopic methods. The 1H- and 13C-NMR spectral data on disaccharide-1-phosphate polymer are presented for the first time.

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.

Carbohydrate-Containing Cell Wall Polymers of Some Strains of the Bacillus subtilis Group

A comparative study of the structures of carbohydrate-containing cell wall polymers isolated from the strains of the Bacillus subtilis group was performed by means of chemical and NMR spectroscopic meth ods. Polymers of different structure were revealed, namely, 1,3-poly(glycerol phosphates) with β-glucopyranose in Bacillus subtilis strains VKM B-520, VKM B-723, and VKM B-763 (= VKM B-911); 1,5-poly(ribitol phosphate) with α-glucopyranose in B. subtilis strains VKM B-722 and VKM B-922 (the structure is reported for the first time); and simultaneously two polymers in B. subtilis VKM B-761, 1,5-poly(ribitol phosphate) with β-glucopyranose and the disaccharide 1-phosphate polymer with the following repeating unit: -6)-α-D-Galp-(1-P-4)-gB-D-GlcpNAc-(1-, in which the hydroxyls at C3 and C6 of glucosamine residues are partially O-acetylated (the structure is reported for the first time). Heterogeneity of the B. subtilis group is con firmed by variations in the structure and composition of the cell wall polymers. The cell surface polymers are useful for discrimination of closely related bacilli strains and are cell wall marker components that may be an indispensable element of the Bacillus subtilis group taxonomy along with the genomosystematic methods.

A novel type of teichoic acid from the cell wall of Bacillus subtilis VKM B-762

The cell wall of Bacillus subtilis VKM B-762 contains, along with 1,5-poly[4-O-(2-acetamido-2-deoxy-β-D-glucopyranosyl)ribitol phosphate], a novel type of glycopolymer involving three types of inter-monomeric bonds in the repeating unit, viz., amide, glycosidic and phosphodiester: [See figure in text]. Such a structural pattern of natural glycopolymers has been hitherto unknown. This polymer represents a novel type of teichoic acids.

Heterogeneous set of cell wall teichoic acids in strains of Bacillus subtilis VKM B-760 and VKM B-764.

Cell walls of Bacillus subtilis VKM B-760 and VKM B-764 are characterized by heterogeneous composition of teichoic acids. Polymer I with structure -6)-β-D-Galp-(1→1)-sn-Gro-(3-P-, polymer II with structure -6)-α-D-Glcp-(1→1)-sn-Gro-(3-P-, and a small amount of unsubstituted 1,3-poly(glycerol phosphate) were detected in strain VKM B-760. Strain VKM B-764 contains an analogous set of teichoic acids, but a characteristic feature of polymer II is the presence of disubstituted glycerol residue with α-glucopyranose localization in the integral chain at C-1 hydroxyl and β-glucopyranose as a side branch at C-2 hydroxyl (polymer III): -6)-α-D-Glcp-(1→1)-[β-D-Glcp-(1→2)]-sn-Gro-(3-P-. The structures of polymer I in bacilli and polymer III in Gram-positive bacteria are described for the first time. Teichoic acids were studied by chemical methods and on the basis of combined analysis of one-dimensional 1H-, 13C-, and 31P-NMR spectra, homonuclear two-dimensional 1H/1H COSY, TOCSY, and ROESY, and heteronuclear two-dimensional 1H/13C gHSQC- and HMQC-TOCSY experiments. Simultaneous presence of several different structure teichoic acids in the bacillus cell walls as well as chemotaxonomical perspectives of the application of these polymers as species-specific markers for members of the Bacillus genus is discussed.

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.

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.