Dissulfurirhabdus thermomarina gen. nov., sp. nov., a thermophilic, autotrophic, sulfite-reducing and disproportionating deltaproteobacterium isolated from a shallow-sea hydrothermal vent T , was isolated from a shallow, submarine hydrothermal vent (Kuril Islands, Russia). Cells of strain SH388 T were Gramstain-negative short rods, 0.2-0.4 µm in diameter and 1.0-2.5 µm in length, and motile with flagella. The temperature range for growth was 25-58 C (optimum 50 C), and the pH range for growth was pH 5.0-7.0 (optimum pH 6.0-6.5). Growth of strain SH388T was observed in the presence of NaCl concentrations ranging from 0.5 to 4.0 % (w/v) (optimum 2.0-2.5 %). The strain grew chemolithoautotrophically with molecular hydrogen as electron donor, sodium sulfite as electron acceptor and bicarbonate/CO 2 as a carbon source. It was also able to grow by disproportionation of sulfite and elemental sulfur but not thiosulfate. Sulfate, Fe(III) and nitrate were not used as electron acceptors either with H 2 or organic electron donors. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belonged to the class Deltaproteobacteria and was most closely related to Dissulfuribacter thermophilus and Dissulfurimicrobium hydrothermale (91.6 % and 90.4 % sequence similarity). On the basis of its physiological properties and results of phylogenetic analyses, strain SH388 T is considered to represent a novel species of a new genus, for which the name Dissulfurirhabdus thermomarina gen. nov., sp. nov. is proposed. The type strain of the species is SH388 T (=DSM 100025. It is the first thermophilic disproportionator of sulfur compounds isolated from a shallow-sea environment.Chemolithoautotrophic micro-organisms can gain energy from a variety of inorganic compounds serving as electron donors and acceptors. Sulfur dioxide is one of the most typical and abundant volcanic gases. It is highly soluble in water; thus, in aquatic environments, including hydrothermal vents, SO 2 is usually present in the form of sulfite ions. Micro-organisms capable of dissimilatory sulfite reduction are phylogenetically diverse and include all sulfate-reducers as well as many nonsulfate-reducing species. Overall, the ability to use sulfite as an electron acceptor with organic or inorganic electron donors is known for representatives of the bacterial phyla Firmicutes, Proteobacteria, Nitrospirae and Thermodesulfobacteria and for archaea of the phyla Crenarchaeota and Euryarchaeota (Simon & Kroneck, 2013; Slobodkin et al., 1999). Some sulfite-reducers are also capable of sulfite disproportionation. Growth coupled to disproportionation of sulfite

In skin, Cutibacterium acnes (former Propionibacterium acnes ) can behave as an opportunistic pathogen, depending on the strain and environmental conditions. Acneic strains of C. acnes form biofilms inside skin–gland hollows, inducing inflammation and skin disorders. The essential exogenous products of C. acnes accumulate in the extracellular matrix of the biofilm, conferring essential bacterial functions to this structure. However, little is known about the actual composition of the biofilm matrix of C. acnes . Here, we developed a new technique for the extraction of the biofilm matrix of Gram-positive bacteria without the use of chemical or enzymatic digestion, known to be a source of artifacts. Our method is based on the physical separation of the cells and matrix of sonicated biofilms by ultracentrifugation through a CsCl gradient. Biofilms were grown on the surface of cellulose acetate filters, and the biomass was collected without contamination by the growth medium. The biofilm matrix of the acneic C. acnes RT5 strain appears to consist mainly of polysaccharides. The following is the ratio of the main matrix components: 62.6% polysaccharides, 9.6% proteins, 4.0% DNA, and 23.8% other compounds (porphyrins precursors and other). The chemical structure of the major polysaccharide was determined using a nuclear magnetic resonance technique, the formula being →6)-α- D -Gal p -(1→4)-β- D -Man p NAc3NAcA-(1→6)-α- D -Glc p -(1→4)-β- D -Man p NAc3NAcA-(1→3)-β-Gal p NAc-(1→. We detected 447 proteins in the matrix, of which the most abundant were the chaperonin GroL, the elongation factors EF-Tu and EF-G, several enzymes of glycolysis, and proteins of unknown function. The matrix also contained more than 20 hydrolases of various substrata, pathogenicity factors, and many intracellular proteins and enzymes. We also performed surface-enhanced Raman spectroscopy analysis of the C. acnes RT5 matrix for the first time, providing the surface-enhanced Raman scattering (SERS) profiles of the C. acnes RT5 biofilm matrix and biofilm biomass. The difference between the matrix and biofilm biomass spectra showed successful matrix extraction rather than simply the presence of cell debris after sonication. These data show the complexity of the biofilm matrix composition and should be essential for the development of new anti- C. acnes biofilms and potential antibiofilm drugs.

Quantum dots (QD) are widely used for cellular labeling due to enhanced brightness, resistance to photobleaching, and multicolor light emissions. CdS and CdxZn1−xS nanoparticles with sizes of 6–8 nm were synthesized via a ligand assisted technique inside and outside of 50 nm diameter halloysite clay nanotubes (QD were immobilized on the tube’s surface). The halloysite–QD composites were tested by labeling human skin fibroblasts and prostate cancer cells. In human cell cultures, halloysite–QD systems were internalized by living cells, and demonstrated intense and stable fluorescence combined with pronounced nanotube light scattering. The best signal stability was observed for QD that were synthesized externally on the amino-grafted halloysite. The best cell viability was observed for CdxZn1−xS QD immobilized onto the azine-grafted halloysite. The possibility to use QD clay nanotube core-shell nanoarchitectures for the intracellular labeling was demonstrated. A pronounced scattering and fluorescence by halloysite–QD systems allows for their promising usage as markers for biomedical applications.

A novel, spore-forming, acidophilic and metal-resistant sulfate-reducing bacterium, strain OLT, was isolated from a microbial mat in a tailing dam at a gold ore mining site. Cells were slightly curved immotile rods, 0.5 µm in diameter and 2.0–3.0 µm long. Cells were stained Gram-negative, despite the Gram-positive cell structure revealed by electron microscopy of ultrathin layers. OLT grew at pH 4.0–7.0 with an optimum at 5.5. OLT utilised H2, lactate, pyruvate, malate, formate, propionate, ethanol, glycerol, glucose, fructose, sucrose, peptone and tryptone as electron donors for sulfate reduction. Sulfate, sulfite, thiosulfate, nitrate and fumarate were used as electron acceptors in the presence of lactate. Elemental sulfur, iron (III), and arsenate did not serve as electron acceptors. The major cellular fatty acids were C16:1ω7c (39.0 %) and C16 : 0 (12.1 %). The draft genome of OLT was 5.29 Mb in size and contained 4909 protein-coding genes. The 16S rRNA gene sequence placed OLT within the phylum Firmicutes , class Clostridia , family Peptococcaceae , genus Desulfosporosinus. Desulfosporosinus nitroreducens 59.4BT was the closest relative with 97.6 % sequence similarity. On the basis of phenotypic and phylogenetic characteristics, strain OLT represents a novel species within the genus Desulfosporosinus , for which we propose the name Desulfosporosinus metallidurans sp. nov. with the type strain OLT (=DSM 104464T=VKM В−3021T).

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A novel moderately thermophilic bacterium, strain STGH(T), was isolated from Severo-Stavropolskoye underground gas storage (Russia). Cells of strain STGH(T) were spore-forming motile straight rods 0.3 μm in diameter and 2.0-4.0 μm in length having a Gram-positive cell wall structure. The temperature range for growth was 36-65 °C, with an optimum at 50-52 °C. The pH range for growth was 5.5-8.0, with an optimum at pH 7.0-7.5. Growth of strain STGH(T) was observed at NaCl concentrations ranging from 0 to 4.0 % (w/v) with an optimum at 1.0 % (w/v). Strain STGH(T) grew anaerobically by reduction of nitrate, thiosulfate, S(0) and AQDS using a number of complex proteinaceous compounds, organic acids and carbohydrates as electron donors. Nitrate was reduced to nitrite; thiosulfate and sulfur were reduced to sulfide. It also was able to ferment pyruvate, glucose, fructose, and maltose. The strain STGH(T) did not grow under aerobic conditions during incubation with atmospheric concentration of oxygen but was able to microaerobic growth (up to 10 % of oxygen in gas phase). The G+C content of DNA of strain STGH(T) was 34.8 mol%. 16S rRNA gene sequence analysis revealed that the isolated organism belongs to the class Bacilli. We propose to assign strain STGH(T) to a new species of a novel genus Tepidibacillus fermentans gen. nov., sp.nov. The type strain is STGH(T) (=DSM 23802(T), =VKM B-2671(T)).

An anaerobic, saccharolytic bacterial strain designated GLS2 T 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 mm. 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 b-lactam antibiotics, rifampicin, streptomycin and vancomycin. Optimum growth was observed between 30 and 34 8C, at pH 6.8-7.5 and with 1-2 g NaCl l 21 .Isolate GLS2 T was a strict anaerobe but it tolerated oxygen exposure. On the basis of 16S rRNA gene sequence similarity, strain GLS2 T was shown to belong to the genus Sphaerochaeta within the family Spirochaetaceae. Its closest relatives were Sphaerochaeta globosa Buddy T (99.3 % 16S rRNA gene sequence similarity) and Sphaerochaeta pleomorpha Grapes T (95.4 % similarity). The G+C content of DNA was 47.2 mol%. The level of DNA-DNA hybridization between strains GLS2 T and Buddy T was 34.7¡8.8 %. Major polar lipids were phosphoglycolipids, phospholipids and glycolipids; major fatty acids were C 14 : 0 , C 16 : 0 , C 16 : 0 3-OH, C 16 : 0 dimethyl acetal (DMA), C 16 : 1n8 and C 16 : 1 DMA; respiratory quinones were not detected. The results of DNA-DNA hybridization, physiological and biochemical tests demonstrated genotypic and phenotypic differentiation of strain GLS2 T 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 GLS2 T therefore represents a novel species, for which the name Sphaerochaeta associata sp. nov. is proposed, with the type strain GLS2 T (5DSM 26261 T 5VKM B-2742 T ).

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