Quantum dots (QD) are widely used for cellular labeling due to enhanced brightness, resistance to photobleaching, and multicolor light emissions. CdS and Cd_xZn_1−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 Cd_xZn_1−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 OL^T, 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. OL^T grew at pH 4.0–7.0 with an optimum at 5.5. OL^T 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 C_16:1ω7c (39.0 %) and C_16 : 0 (12.1 %). The draft genome of OL^T was 5.29 Mb in size and contained 4909 protein-coding genes. The 16S rRNA gene sequence placed OL^T within the phylum Firmicutes , class Clostridia , family Peptococcaceae , genus Desulfosporosinus. Desulfosporosinus nitroreducens 59.4B^T was the closest relative with 97.6 % sequence similarity. On the basis of phenotypic and phylogenetic characteristics, strain OL^T represents a novel species within the genus Desulfosporosinus , for which we propose the name Desulfosporosinus metallidurans sp. nov. with the type strain OL^T (=DSM 104464^T=VKM В−3021^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 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 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 ( = DSM 26261^T = VKM B-2742^T).

A thermophilic, anaerobic, chemolithoautotrophic bacterium, strain SH388T, was isolated from a shallow, submarine hydrothermal vent (Kuril Islands, Russia). Cells of strain SH388T were Gram-stain-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/CO2 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 H2 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 SH388T 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 SH388T (=DSM 100025T=VKM B-2960T). It is the first thermophilic disproportionator of sulfur compounds isolated from a shallow-sea environment.

First introduced in 1954, polyurethane foams rapidly became popular because of light weight, high chemical stability, and outstanding sound and thermal insulation properties. Currently, polyurethane foam is widely applied in industrial and household products. Despite tremendous progress in the development of various formulations of versatile foams, their use is hindered due to high flammability. Fire retardant additives can be introduced into polyurethane foams to enhance their fireproof properties. Nanoscale materials employed as fire-retardant components of polyurethane foams have the potential to overcome this problem. Here, we review the recent (last 5 years) progress that has been made in polyurethane foam modification using nanomaterials to enhance its flame retardance. Different groups of nanomaterials and approaches for incorporating them into foam structures are covered. Special attention is given to the synergetic effects of nanomaterials with other flame-retardant additives.