The Qaidam Basin is the highest and one of the largest and driest deserts on Earth. It is considered a mars analog area in China. In contrast to numerous studies concerning its geology, geophysical, and chemistry, relatively few studies have reported microbial diversity and distribution in this area. Here, we investigated culturable yeast diversity in the northeast Qaidam Basin. A total of 194 yeast strains were isolated, and 12 genera and 21 species were identified, among which 19 were basidiomycetous yeasts. Naganishia albida, N. adeliensis, and Filobasidium magnum were the three most dominant species and were distributed in thirteen samples from eight locations. Five new species (Filobasidium chaidanensis, Kondoa globosum, Symmetrospora salmoneus, Teunia nitrariae, and Vishniacozyma pseudodimennae) were found and described based on ITS and D1D2 gene loci together with phenotypic characteristics and physiochemical analysis. Representative strains from each species were chosen for the salt-tolerant test, in which species showed different responses to different levels of NaCl concentrations. Further, the strain from soil can adapt well to the higher salt stress compared to those from plants or lichens. Our study represents the first report of the yeast diversity in the Qaidam Basin, including five new species, and also provides further information on the halotolerance of yeasts from the saline environment in mars analog.

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).

Fermented foods have been produced by humans since prehistoric times and are consumed worldwide today due to their enhanced nutritional value, taste and flavor, and benefits for human health. Various microorganisms are essential agents responsible for food fermentation and have been extensively studied using both culture-dependent and -independent methods. However, previous research has mainly focused on fermented foods produced on a large scale in urbanized areas. In this study, we collected 255 samples of diverse traditional fermented foods—including alcoholic beverages, amylolytic starters, fruit vinegar, and fermented products of milk, vegetables, cereals, legumes, fish, meat, and other materials—from ethnic minority areas of China through a citizen science initiative for the study of yeast diversity. A total of 516 yeast strains were isolated, and 81 yeast species, including four new species, were identified based on sequence analyses of the D1/D2 domain of the large subunit rRNA gene and the internal transcribed spacer region. The proposals of the new species were further supported by whole-genome average nucleotide identity (ANI) analysis. The dominant species isolated were Saccharomyces cerevisiae, Pichia kudriavzevii, Wickerhamomyces anomalus, Saccharomycopsis fibuligera, and Clavispora lusitaniae. The new species are described as Blastobotrys guizhouensissp. nov., Wickerhamiella shiruiisp. nov., Trichosporon jiuqusp. nov., and Parajaminaea albasp. nov. This study demonstrates the high yeast diversity in traditional fermented foods of ethnic minorities in China. These yeast resources are of special value for both basic and applied research in the future.

Two bacterial strains, designated B2N2-7^T and B2N2-12, were isolated from Buteha crater lake in the Greater Khingan Mountain of China. The two strains were Gram-stain-negative, non-spore-forming, motile with a single polar flagellum, short rod-shaped bacteria. They were catalase- and oxidase-positive. Optimal growth occurred at 20–25 ℃, at pH 7.5–8.0 and with 0–1.0 % (w/v) NaCl. Based on phylogenomic analysis, strains B2N2-7^T and B2N2-12 were assigned to the family Neisseriaceae , and their 16S rRNA gene sequences showed the highest similarities to that of Aquitalea denitrificans 5YN1-3^T (<94.2 %). The predominant cellular fatty acids were C_16 : 0 and summed feature 3 (comprising C_16 : 1ω7c/C_16 : 1 ω6c). The major respiratory quinone was ubiquinone 8 (Q-8). The polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), two unidentified aminophospholipids (APL) and some unidentified lipids (L). The genomic DNA G+C content of strain B2N2-7^T was 59.4 mol% according to the genomic sequencing result. Based on the phylogenetic, genotypic and chemotaxonomic analyses, the two strains are proposed to represent a novel species of a new genus in the family Neisseriaceae , named Craterilacuibacter sinensis gen. nov., sp. nov. The type strain of Craterilacuibacter sinensis is B2N2-7^T (=CGMCC 1.17189^T=KCTC 73735^T); B2N2-12 (=CGMCC 1.17190=KCTC 72734) is a second strain of the species.

Two yeast strains representing a novel species in the basidiomycetous yeast genus Naganishia were isolated from flowers of Sorbaria sorbifolia collected in Beijing Olympic Forest Park, PR China. Results of multi-gene phylogenetic analysis indicated that the two strains were closely related to the type strains of Naganishia bhutanensis (CBS 6294^T) and Naganishia antarctica (CBS 7687^T). However, the new isolates differed from N. bhutanensis CBS 6294^T by 1.79 % sequence divergence in the D1/D2 domain (11 nt substitutions and three indels), and 2.42 % (15 nt differences and one indel) to N. antarctica CBS 7687^T. In the ITS region, the new isolates showed 1.15 % divergence (7 nt substitutions and one indel) to N. bhutanensis CBS 6294^T and 0.92 % divergence (5 nt substitutions and no indels) to N. antarctica CBS 7687^T. A phylogenetic analysis employing the sequences of six genes (D1/D2 domain of large subunit rDNA, ITS, small subunit rDNA, two subunits of the RNA polymerase II and elongation factor-1α) indicated that the novel species belonged to the genus Naganishia and formed a well-supported clade with N. bhutanensis, N. antarctica and N. indica. Moreover, the two strains differed from their closest relatives by the ability to grow on distinct carbon and nitrogen sources and ability to grow at 30 °C. On the basis of these findings, we propose a novel species in the genus Naganishia (Filobasidiales), Naganishia floricola sp. nov. (holotype CGMCC 2.5856).