A novel alkaliphilic, sulfate-reducing bacterium, strain MLF1T, was isolated from sediments of soda Mono Lake, California. Gram-negative vibrio-shaped cells were observed, which were 0·6–0·7×1·2–2·7 μm in size, motile by a single polar flagellum and occurred singly, in pairs or as short spirilla. Growth was observed at 15–48 °C (optimum, 37 °C), >1–7 % NaCl, w/v (optimum, 3 %) and pH 8·0–10·0 (optimum, 9·5). The novel isolate is strictly alkaliphilic, requires a high concentration of carbonate in the growth medium and is obligately anaerobic and catalase-negative. As electron donors, strain MLF1T uses hydrogen, formate and ethanol. Sulfate, sulfite and thiosulfate (but not sulfur or nitrate) can be used as electron acceptors. The novel isolate is a lithoheterotroph and a facultative lithoautotroph that is able to grow on hydrogen without an organic source of carbon. Strain MLF1T is resistant to kanamycin and gentamicin, but sensitive to chloramphenicol and tetracycline. The DNA G+C content is 63·0 mol% (HPLC). DNA–DNA hybridization with the most closely related species, Desulfonatronum lacustre Z-7951T, exhibited 51 % homology. Also, the genome size (1·6×109 Da) and T m value of the genomic DNA (71±2 °C) for strain MLF1T were significantly different from the genome size (2·1×109 Da) and T m value (63±2 °C) for Desulfonatronum lacustre Z-7951T. On the basis of physiological and molecular properties, the isolate was considered to be a novel species of the genus Desulfonatronum, for which the name Desulfonatronum thiodismutans sp. nov. is proposed (the type strain is MLF1T=ATCC BAA-395T=DSM 14708T).

A novel, obligately anaerobic, mesophilic, haloalkaliphilic spirochaete, strain ASpG1^T, was isolated from sediments of the alkaline, hypersaline Mono Lake in California, USA. Cells of the Gram-negative strain were motile and spirochaete-shaped with sizes of 0·2–0·22×8–18 μm. Growth of the strain was observed between 10 and 44 °C (optimum 37 °C), in 2–12 % (w/v) NaCl (optimum 3 % NaCl) and between pH 8 and 10·5 (optimum pH 9·5). The novel strain was strictly alkaliphilic, required high concentrations of carbonates in the medium and was capable of utilizing d-glucose, fructose, maltose, sucrose, starch and d-mannitol. End products of glucose fermentation were H₂, acetate, ethanol and formate. Strain ASpG1^T was resistant to kanamycin and rifampicin, but sensitive to gentamicin, tetracycline and chloramphenicol. The G+C content of its DNA was 58·5 mol%. DNA–DNA hybridization analysis of strain ASpG1^T with its most closely related species, Spirochaeta alkalica Z-7491^T, revealed a hybridization value of only 48·7 %. On the basis of its physiological and molecular properties, strain ASpG1^T appears to represent a novel species of the genus Spirochaeta, for which the name Spirochaeta americana is proposed (type strain ASpG1^T=ATCC BAA-392^T=DSM 14872^T).

Methodologies to improve existing adeno-associated virus (AAV) vectors for gene therapy include either rational approaches or directed evolution to derive capsid variants characterized by superior transduction efficiencies in targeted tissues. Here, we integrated both approaches in one unified design strategy of "virtual family shuffling" to derive a combinatorial capsid library whereby only variable regions on the surface of the capsid are modified. Individual sublibraries were first assembled in order to preselect compatible amino acid residues within restricted surface-exposed regions to minimize the generation of dead-end variants. Subsequently, the successful families were interbred to derive a combined library of ~8 × 10(5) complexity. Next-generation sequencing of the packaged viral DNA revealed capsid surface areas susceptible to directed evolution, thus providing guidance for future designs. We demonstrated the utility of the library by deriving an AAV2-based vector characterized by a 20-fold higher transduction efficiency in murine liver, now equivalent to that of AAV8.

A novel, psychrotolerant, facultative anaerobe, strain FTR1^T, was isolated from Pleistocene ice from the permafrost tunnel in Fox, Alaska. Gram-positive, motile, rod-shaped cells were observed with sizes 0·6–0·7×0·9–1·5 μm. Growth occurred within the pH range 6·5–9·5 with optimum growth at pH 7·3–7·5. The temperature range for growth of the novel isolate was 0–28 °C and optimum growth occurred at 24 °C. The novel isolate does not require NaCl; growth was observed between 0 and 5 % NaCl with optimum growth at 0·5 % (w/v). The novel isolate was a catalase-negative chemoorganoheterotroph that used as substrates sugars and some products of proteolysis. The metabolic end products were acetate, ethanol and CO₂. Strain FTR1^Twas sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. 16S rRNA gene sequence analysis showed 99·8 % similarity between strain FTR1^TandCarnobacterium alterfunditum, but DNA–DNA hybridization between them demonstrated 39±1·5 % relatedness. On the basis of genotypic and phenotypic characteristics, it is proposed that strain FTR1^T(=ATCC BAA-754^T=JCM 12174^T=CIP 108033^T) be assigned to the novel speciesCarnobacterium pleistoceniumsp. nov.

A novel, extremely psychrotolerant, facultative anaerobe, strain PmagG1^T, was isolated from guano of Magellanic penguins (Spheniscus magellanicus) collected in Chilean Patagonia. Gram-variable, motile cocci with a diameter of 1.3–2.0 μm were observed singularly or in pairs, short chains and irregular conglomerates. Growth occurred within the pH range 6.0–10.0, with optimum growth at pH 8.5. The temperature range for growth of the novel isolate was from −5 to 35 °C, with optimum growth at 28–30 °C. Strain PmagG1^Tdid not require NaCl, as growth was observed in the presence of 0–6.5 % NaCl with optimum growth at 0.5 % (w/v). Strain PmagG1^Twas a catalase-negative chemo-organoheterotroph that used sugars and some organic acids as substrates. The metabolic end products were lactate, formate, acetate, ethanol and CO₂. Strain PmagG1^Twas sensitive to ampicillin, tetracycline, chloramphenicol, rifampicin, kanamycin and gentamicin. The G+C content of its genomic DNA was 45.8 mol%. 16S rRNA gene sequence analysis showed 100 % similarity of strain PmagG1^TwithTrichococcus collinsiiATCC BAA-296^T, but DNA–DNA hybridization between them demonstrated relatedness values of <45±1 %. Another phylogenetically closely related species,Trichococcus pasteurii, showed 99.85 % similarity by 16S rRNA sequencing and DNA–DNA hybridization showed relatedness values of 47±1.5 %. Based on genotypic and phenotypic characteristics, the novel speciesTrichococcus patagoniensissp. nov. is proposed, with strain PmagG1^T(=ATCC BAA-756^T=JCM 12176^T=CIP 108035^T) as the type strain.

A novel, obligately anaerobic, psychrotolerant bacterium, designated strain PPP2^T, was isolated from guano of the Magellanic penguin (Spheniscus magellanicus) in Chilean Patagonia. Cells were Gram-stain-positive, spore-forming, straight rods (0.7–0.8×3.0–5.0 μm) that were motile by means of peritrichous flagella. Growth was observed at pH 6.7−9.7 (optimum pH 8.3) and 2–37 °C (optimum 29 °C). Growth was observed between 0 and 4 % (w/v) NaCl with optimum growth at 0.5 % (w/v). Strain PPP2^T was a catalase-negative chemo-organoheterotroph that was capable of fermentative metabolism. Peptone, bacto-tryptone, Casamino acids, oxalate, starch, chitin and yeast extract were utilized as substrates. The major metabolic products were acetate, butyrate and ethanol. Strain PPP2^T was resistant to ampicillin, but sensitive to tetracycline, chloramphenicol, rifampicin, kanamycin, vancomycin and gentamicin. The DNA G+C content of strain PPP2^T was 39.5 mol%. Phylogenetic analysis revealed that strain PPP2^T was related most closely to Clostridium sticklandii SR (∼90 % 16S rRNA gene sequence similarity). On the basis of phylogenetic analysis and phenotypic characteristics, strain PPP2^T is considered to represent a novel species of a new genus, for which the name Proteocatella sphenisci gen. nov., sp. nov. is proposed. The type strain of Proteocatella sphenisci is PPP2^T (=ATCC BAA-755^T =JCM 12175^T =CIP 108034^T).