Tabrizicola sediminis sp. nov., one aerobic anoxygenic photoheterotrophic bacteria from sediment of saline lake.

Two strains of Gram-stain-negative, non-motile, aerobic, short-rod bacteria, designated as DRYC-M-16T and WMC-M-20, were isolated from sediment samples of two saline lakes in the Tibet of China. Both of the strains were catalase- and oxidase-positive. Optimal growth of strain DRYC-M-16T occurred at 20-25 °C, pH 7.0-7.5 and with 1.5 % (w/v) NaCl concentration. The analysis of 16S rRNA gene sequences indicated that strains DRYC-M-16T and WMC-M-20 belonged to the genus Tabrizicola, and showed the highest similarities to Tabrizicola aquatica KCTC 23724T (96.9 %) and Tabrizicola fusiformis KCTC 62105T (96.7 %). The DNA G+C contents of strains DRYC-M-16T and WMC-M-20 were 63.0 mol% and 62.9 mol%, respectively. The main polar lipids contained phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and several unidentified aminophospholipid (APL), aminolipid (AL), phospholipids (PL) and lipids (L). The predominant respiratory quinone was ubiquinone Q-10. The major cellular fatty acids of the two strains were iso-C18 : 0 and summed feature 8 (comprising C18 : 1 ω7c/C18 : 1 ω6c). Comprehensive analysis of the genotypic, physiological, biochemical and phenotypic characteristics indicated that the two strains should be classified as a novel species of the genus Tabrizicola, proposed as Tabrizicola sediminissp. nov., with the type strain DRYC-M-16T (=CGMCC 1.13881T=KCTC 72105 T).

New Germplasms of the Culinary-Medicinal Button Mushroom, Agaricus bisporus (Agaricomycetes): Two Wild Strains from the Tibetan Plateau (China).

Agaricus bisporus is one of the most important commercially cultivated culinary-medicinal mushrooms worldwide. In China, most of the cultivated strains of the fungus were introduced from other countries and cultivated in the eastern provinces. In this study, 2 wild strains of A. bisporus, 2091 and 2094, isolated from fresh specimens collected from the Tibetan Plateau, were domesticated and cultivated alongside a commercial hybrid strain, As2796, in Lhasa, China, for comparison in order to provide new germplasms for cultivation. Basic characteristics, mushroom yield, dry weight, polysaccharide contents, and antioxidant activities of the tested strains were analyzed. Compared with strain As2796, the 2 wild strains displayed good values for mycelial growth, time to fruiting, mushroom yield, dry weight, and polysaccharide contents, and their basidiomata had distinct morphological characteristics (e.g., brown or pale brown caps with some white scales). In addition, the antioxidant activities (reducing power and DPPH radical scavenging effect) of strain 2094 were significantly higher than those of the other 2 strains. Domestication of the 2 wild strains would add more genetic variation into the germplasm of A. bisporus for cultivation, especially in China, and might help to address the problem inherent to the nearly monoculture crop lacking genetic diversity in China.