Danxiaibacter flavus gen. nov., sp. nov., a novel bacterium of the family Chitinophagaceae isolated from forest soil on Danxia Mountain.

A Gram-stain-negative, aerobic, short rod-shaped, yellow bacterium, designated SYSU DXS3180T, was isolated from forest soil of Danxia Mountain in PR China. Growth occurred at 15-37 °C (optimum, 28-30 °C), pH 6.0-10.0 (optimum, pH 7.0-8.0) and with 0-2.0 % NaCl (optimum, 0-0.5 %, w/v). Strain SYSU DXS3180T was positive for hydrolysis of Tween 20, Tween 60, Tween 80 and starch, but negative for urease, H2S production, nitrate reduction, Tween 40 and gelatin. Phylogenetic analysis based on 16S rRNA gene and genome sequences showed that SYSU DXS3180T belonged to the family Chitinophagaceae. The closely related members were Foetidibacter luteolus YG09T (94.2 %), Limnovirga soli KCS-6T (93.9 %) and Filimonas endophytica SR 2-06T (93.7 %). The genome of strain SYSU DXS3180T was 7287640 bp with 5782 protein-coding genes, and the genomic DNA G+C content was 41.4 mol%. The main respiratory quinone was MK-7 and the major fatty acids (>10 %) were iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1 G. The major polar lipids consisted of phosphatidylethanolamine, two unidentified aminolipids and two unidentified polar lipids. Based on the phylogenetic, phenotypic and chemotaxonomic characteristics, strain SYSU DXS3180T is proposed to represent a novel species of a novel genus named Danxiaibacter flavus gen. nov., sp. nov., within the family Chitinophagaceae. The type strain is SYSU DXS3180T (=KCTC 92895T=GDMCC 1.3825 T).

Telluribacter roseus sp. nov., Isolated from the Kumtag Desert Soil.

A pink-pigmented bacterium, designated as strain SYSU D00476T, was isolated from sandy soil collected from the Kumtag Desert in China. Colonies were opaque, smooth and of a slight convexity with a clearly defined border. Cells were rod-shaped, Gram-stain-negative, catalase- and oxidase-positive. Growth occurred at 4-45 ℃ (optimum at 28-30 ℃), pH 6.0-8.0 (optimum at 7.0), and with 0-3.0% NaCl (w/v, optimum at 0-2.0%). Major fatty acids (> 10%) were C16:0, summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), iso-C17:0 3-OH and iso-C15:0. Polar lipids comprised of three unidentified polar aminolipids (ALs), two unidentified aminophosphoglycolipids (APLs), one unidentified glycolipid (GL) and three unidentified phospholipids (PLs). The predominant respiratory quinone was MK-7. The genomic DNA G + C content was 50.5%. The low digital DNA-DNA hybridization (dDDH, 27.4%) and average nucleotide identity (ANI, 85%) values between strain SYSU D00476T and Telluribacter humicola KCTC 42819T indicated that SYSU D00476T represent a distinct species. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D00476T belonged to the genus Telluribacter, showing 97.5% similarity with T. humicola KCTC 42819T. All these data support that strain SYSU D00476T represent a novel species of the genus Telluribacter within the family Spirosomataceae, named as Telluribacter roseus sp. nov. The type strain is SYSU D00476T (= KCTC 82285T = CGMCC 1.18647T = MCCC 1K04983T).

Capturing the microbial dark matter in desert soils using culturomics-based metagenomics and high-resolution analysis.

Deserts occupy one-third of the Earth's terrestrial surface and represent a potentially significant reservoir of microbial biodiversity, yet the majority of desert microorganisms remain uncharacterized and are seen as "microbial dark matter". Here, we introduce a multi-omics strategy, culturomics-based metagenomics (CBM) that integrates large-scale cultivation, full-length 16S rRNA gene amplicon, and shotgun metagenomic sequencing. The results showed that CBM captured a significant amount of taxonomic and functional diversity missed in direct sequencing by increasing the recovery of amplicon sequence variants (ASVs) and high/medium-quality metagenome-assembled genomes (MAGs). Importantly, CBM allowed the post hoc recovery of microbes of interest (e.g., novel or specific taxa), even those with extremely low abundance in the culture. Furthermore, strain-level analyses based on CBM and direct sequencing revealed that the desert soils harbored a considerable number of novel bacterial candidates (1941, 51.4%), of which 1095 (from CBM) were culturable. However, CBM would not exactly reflect the relative abundance of true microbial composition and functional pathways in the in situ environment, and its use coupled with direct metagenomic sequencing could provide greater insight into desert microbiomes. Overall, this study exemplifies the CBM strategy with high-resolution is an ideal way to deeply explore the untapped novel bacterial resources in desert soils, and substantially expands our knowledge on the microbial dark matter hidden in the vast expanse of deserts.

Rubellimicrobium arenae sp. nov., isolated from desert soil.

Two Gram-stain-negative strains, designated as SYSU D00286T and SYSU D00782, were isolated from a sand sample collected from the Kumtag Desert in Xinjiang, north-west China. Cells were aerobic, non-motile and positive for both oxidase and catalase. Growth occurred at 4-37 °C (optimum, 28-30 °C), pH 6.0-7.0 (optimum, pH 7.0) and NaCl concentration of 0-1.5 % (w/v; optimum, 0%). Growth was observed on Reasoner's 2A agar and nutrient agar, but not on Luria-Bertani agar and trypticase soy agar. The polar lipids were identified as diphosphatidylglycerol, phosphatidylcholine, phosphatidylglycerol, three unidentified aminolipids, one unidentified glycolipid and two unidentified phospholipids. The major respiratory quinone was ubiquinone-10 and the major fatty acids (>10 %) were C16 : 0 and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The 16S rRNA gene sequence similarity between strains SYSU D00286T and SYSU D00782 was 100%, and their average nucleotide identity (ANI), average amino acid identity and (AAI) digital DNA-DNA hybridization (dDDH) values were all 100.0 %. Phylogenetic analysis indicated that these two strains belong to the same species of the genus Rubellimicrobium and show the highest sequence similarity to Rubellimicrobium rubrum KCTC 72461T (98.2 %) and Rubellimicrobium roseum CCTCC AA 208029T (97.5 %). The ANI, AAI and dDDH values between SYSU D00286T (as well as SYSU D00782) and the other five Rubellimicrobium type strains were all less than or equal to 83.2, 80.1 and 23.6 %, respectively. Based on their phylogenetic, phenotypic and chemotaxonomical features, strains SYSU D00286T and SYSU D00782 represent a novel species of the genus Rubellimicrobium, for which the name Rubellimicrobium arenae sp. nov. is proposed. The type strain is SYSU D00286T (=MCCC 1K04981T=CGMCC 1.8626T=KCTC 82271T).

Aridibaculum aurantiacum gen. nov., sp. nov., isolated from the Kumtag Desert soil.

A novel orange-coloured bacterium, designated strain SYSU D00508T, was isolated from a sandy soil sampled from the Kumtag Desert in China. Strain SYSU D00508T was aerobic, Gram-stain-negative, oxidase-positive, catalase-positive and non-motile. Growth occurred at 4-45°C (optimum 28-30°C), pH 6.0-9.0 (optimum pH 7.0-8.0) and with 0-2.5 % NaCl (w/v, optimum 0-1.0 %). The major polar lipids consisted of phosphatidylethanolamine (PE), unidentified aminolipids (AL1-3) and unidentified polar lipids (L1-5) were also detected. The major respiratory quinone was MK-7 and the major fatty acids (>10 %) were iso-C17 : 0 3-OH, iso-C15 : 0 and iso-C15 : 1 G. The genomic DNA G+C content was 42.6 %. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SYSU D00508T belonged to the family Chitinophagaceae and showed 93.9 % (Segetibacter koreensis DSM18137T), 92.9 % (Segetibacter aerophilus NBRC 106135T), 93.0 % (Terrimonas soli JCM 32095T) and 92.8 % (Parasegetibacter terrae JCM 19942T) similarities. Based on the phylogenetic, phenotypic and chemotaxonomic data, strain SYSU D00508T is proposed to represent a novel species of a new genus, named Aridibaculum aurantiacum gen. nov., sp. nov., within the family Chitinophagaceae. The type strain is SYSU D00508T (=KCTC 82286T=CGMCC 1.18648T=MCCC 1K05005T).

Longitalea arenae gen. nov., sp. nov. and Longitalea luteola sp. nov., two new members of the family Chitinophagaceae isolated from desert soil.

Two strains designated as SYSU D01084T and SYSU D00799T, were isolated from a sandy soil sample collected from Gurbantunggut Desert in Xinjiang, north-west China. Cells of both strains were Gram-stain-negative, strictly aerobic, long-rod-shaped, oxidase- and catalase-negative, motile or non-motile. Colonies were circular, translucent, convex, smooth and light-yellow in color on R2A agar. The two isolates were found to grow at 4-50 ºC, at pH 6.0-8.0 and with 0-1.0% (w/v) NaCl. Analysis of their 16S rRNA gene sequences indicated that they belonged to the family Chitinophagaceae, and closely related to the genera Paraflavitalea, Niastella, Pseudoflavitalea and Flavitalea. The two novel strains shared 98.1% 16S rRNA sequence similarity and represent different species on the basis of low average nucleotide identity (ANI, 83.8%) and digital DNA-DNA hybridization (dDDH, 51.4%) values. The genomic DNA G + C contents of strains SYSU D01084T and SYSU D00799T were 46.0 and 45.6%, respectively. Phylogenetic trees showed that the two isolates were clustered in an individual lineage and not grouped consistently into any specific genus. The polar lipids contained of phosphatidylethanolamine, four unidentified aminolipids, two unidentified aminoglycolipids, and three or four unidentified lipids. The predominant respiratory quinone was MK-7 and the major fatty acids (> 10%) were identified as iso-C15:0, iso-C17:0 3-OH, and iso-C15:1 G. Based on the combined phenotypic, genomic and phylogenetic analyses, the two strains represent two novel species of a new genus in the family Chitinophagaceae, for which the name Longitalea gen. nov. is proposed, comprising the type species Longitalea arenae sp. nov. (type strain SYSU D01084T = CGMCC 1.18641T = MCCC 1K05006T = KCTC 82283T) and Longitalea luteola sp. nov. (type strain SYSU D00799T = MCCC 1K04987T = KCTC 82282T = NBRC 114888T).

Sabulibacter ruber gen. nov., sp. nov., a novel bacterium in the family Hymenobacteraceae, isolated from desert soil.

A novel Gram-stain-negative, aerobic, oxidase-positive, catalase-positive, non-motile, short rod-shaped, red-pigmented strain, designated as SYSU D00434T, was isolated from a dry sandy soil sample collected from the Gurbantunggut desert in Xinjiang, north-west PR China. Strain SYSU D00434T was found to grow at 4-37 °C (optimum, 28-30 °C), pH 6.0-8.0 (optimum, pH 7.0) and with 0-1.5 % (w/v) NaCl (optimum, 0-0.5 %). The predominant respiratory quinone was MK-7 and the major fatty acids (>10 %) were C16 : 1 ω5c, iso-C15 : 0, summed feature 3 (C16 : 1 ω6c and/or C16 : 1 ω7c) and summed feature 4 (anteiso-C17 : 1 B and/or iso-C17 : 1 I). The polar lipids consisted of phosphatidylethanolamine, two unidentified polar lipids, two unidentified aminolipids, two unidentified phospholipids and two unidentified glycolipids. The genomic DNA G+C content of strain SYSU D00434T was 50.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYSU D00434T belonged to the family Hymenobacteraceae, and shared a sequence similarity of less than 94.6 % to all validly named taxa. Based on the phenotypic, phylogenetic and chemotaxonomic properties, strain D00434T is proposed to represent a new species of a new genus, named Sabulibacter ruber gen. nov., sp. nov., within the family Hymenobacteraceae. The type strain is SYSU D00434T (=CGMCC 1.18624T=KCTC 82276T=MCCC 1K04975T).

[Influence of CNTs on Photodegradation of Salbutamol in Water Environment].

The influence of CNTs on the photolysis of organic pollutant was investigated by studying the photodegradation kinetics of SAL under 1000 W Xenon lamp, in the presence of three kinds of CNTs (SCNT, MWNT-COOH, MWNT-OH). In addition, the interaction between CNTs and Fe3" was also investigated. The results showed that the photodegradation of salbutamol followed pseudo-first-order kinetics, which could be inhibited by all three kinds of CNTs through light screening effect. Formation of singlet oxygen was detected during the photolysis, using the molecular probe furfuryl alcohol. All three kinds of CNTs could absorb electrons through competition, i.e., inhibit SAL photodegradation by light screening effect; meanwhile, the CNTs could generate singlet oxygen through photoexcitation to promote the photodegradation reaction. Both mechanisms coexisted, and in most cases, the inhibition effect was dominant. In addition, CNTs could inactivate the photoactive substance Fe3 in the water body by electrostatic adsorption, and affect the photochemical behavior of organic pollutants in natural water body.

[Effect of sappan wood on perforin mRNA expression in myocardium of rats after allogeneic cardiac transplantation].

OBJECTIVE: To observe the effect of Sappan wood (SW) on the expression of perforin mRNA in myocardium of rats after allogeneic cardiac transplantation. METHODS: The animal model of allogeneic (abdominal) cardiac transplantation was established by taking Wistar rat as provider and SD rat as receptor, perforin mRNA expression in the model's myocardium was detected by RT-PCR. RESULTS: SW could obviously reduce the perforin mRNA expression, it also could alleviate the pathological morphology and ultrastructural damage of myocardial cells. CONCLUSION: SW has obvious effect in antagonizing immune rejection after transplantation, the mechanism of its immunosuppression could be through lowering the perforin mRNA expression.