Paenibacillus thermotolerans sp. nov., isolated from a hot spring in Yunnan Province, south-west China.

Two Gram-positive, rod-shaped, endospore-forming strains, YIM B05601 and YIM B05602T, were isolated from soil sampled at Hamazui hot spring, Tengchong City, Yunnan Province, PR China. Phylogenetic analysis based on 16S rRNA gene sequences suggested that the two strains fell within the genus Paenibacillus, appearing most closely related to Paenibacillus alkalitolerans YIM B00362T (96.9 % sequence similarity). Genome-based phylogenetic analysis confirmed that strains YIM B05601 and YIM B05602T formed a distinct phylogenetic cluster within the genus Paenibacillus. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values of strains YIM B05601 and YIM B05602T with the related species P. alkalitolerans YIM B00362T were within the ranges of 74.43-74.57 % and 12.1-18.5 %, respectively, which clearly indicated that strains YIM B05601, YIM B05602T represented a novel species. Strains YIM B05601 and YIM B05602T exhibited 99.6 % 16S rRNA gene sequence similarity. The ANI and dDDH values between the two strains were 99.8 and 100 %, respectively, suggesting that they belong to the same species. Optimum growth for both strains occurred at pH 7.0 and 45 °C. The diagnostic diamino acid in the cell-wall peptidoglycan of strains YIM B05601 and YIM B05602T was meso-diaminopimelic acid. MK-7 was the predominant menaquinone. The polar lipids of strain YIM B05602T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, four unidentified glycolipids, an unidentified polarlipid and phosphatidylinositol mannoside. The major fatty acids of the two stains were iso-C15 : 0 and anteiso-C15 : 0. Based on phylogenomic and phylogenetic analyses coupled with phenotypic and chemotaxonomic characterizations, strains YIM B05601 and YIM B05602T could be classified as a novel species of the genus Paenibacillus, for which the name Paenibacillus thermotolerans sp. nov. is proposed. The type strain is YIM B05602T (=CGMCC 1.60051T=KCTC 43460T=NBRC 115924T).

Abreast insights of harnessing microalgal lipids for producing biodiesel: A review of improving and advancing the technical aspects of cultivation.

In the pursuit of alternatives for conventional diesel, sourced from non-renewable fossil fuel, biodiesel has gained attentions for its intrinsic benefits. However, the commercial production process for biodiesel is still not sufficiently competitive. This review analyses microalgal lipid, one of the important sources of biodiesel, and its cultivation techniques with recent developments in the technical aspects. In fact, the microalgal lipids are the third generation feedstock, used for biodiesel production after its benefits outweigh that of edible vegetable oils (first generation) and non-edible oils (second generation). The critical factors influencing microalgal growth and its lipid production and accumulation are also discussed. Following that is the internal enhancement for cellular lipid production through genetic engineering. Moreover, the microalgae cultivation data modelling was also rationalized, with a specific focus on growth kinetic models that allow for the prediction and optimization of lipid production. Finally, the machine learning and environmental impact analysis are as well presented as important aspects to consider in fulfilling the prime objective of commercial sustainability to produce microalgal biodiesel.

Parapedobacter tibetensis sp. nov., isolated from shore soil of saline lake in Tibet of China and its genome mining of secondary metabolite.

Five aerobic, Gram-stain-negative, non-motile, non-spore-forming, short rod bacteria strains, designated as C3-1-R+6T, C3-2-M9, B3-2-R-7, B3-2-R-21 and C3-2-M2, were isolated from shore soil of LungmuCo Lake in Tibet of China. The 16S rRNA gene sequence comparisons confirmed their affiliation to the genus Parapedobacter of the family Sphingobacteriaceae, and showed that they were most closely related to Parapedobacter lycopersici KACC 18788T with 94.26 % similarities. The average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between them and the validly published Parapedobacter species were all below the thresholds for delineating species, supporting that they were novel species of genus Parapedobacter. The ANI, AAI and dDDH values between strains C3-1-R+6T and Parapedobacter lycopersici KACC 18788T were 72, 75, and 18% respectively. Meanwhile, the ANI/AAI and dDDH values between these five isolates were higher than the threshold values, showing that they belonged to the same species of Parapedobacter. According to genome comparison, the novel isolates have some special biosynthetic gene clusters of secondary metabolites including bacteriton, aryl-polyene, lantipeptide and t1pks, which were absent from their most related phylogenetic neighbours P. lycopersici KACC 18788T and P. pyrenivorans CGMCC 1.12195T. The main polar lipids contained phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid, one unidentified glycolipid and five unidentified lipids. The predominant respiratory quinone was MK-7. The major cellular fatty acids were iso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and iso-C17 : 0 3-OH. The genome size of strain C3-1-R+6T was 5 984 948 bp, and its genomic DNA G+C content was 46.21 mol%. To sum up, the five strains were identified as a novel species of the genus Parapedobacter, for which the name Parapedobacter tibetensis sp. nov. was proposed. The type strain was C3-1-R+6T (=CGMCC 1.19194T=KCTC 92150T).

Aquiflexum gelatinilyticum sp. nov., isolated from river water.

Two Gram-stain-negative, strictly aerobic, rod-shaped, non-motile and non-gliding bacteria, designated as XJ19-10T and XJ19-11, were isolated from river water in Xinjiang Uygur Autonomous Region, PR China. Cells of these strains were catalase-, oxidase- and gelatinase-positive and contained carotenoids but no flexirubins. Growth occurred at 10-30 °C, pH 7.0-9.0 and with 0-2.5% (w/v) NaCl. On the basis of the results of 16S rRNA gene sequence and genome analyses, the two isolates represented members of the genus Aquiflexum, and the closest relative was Aquiflexum aquatile Z0201T with 16S rRNA gene sequence pairwise similarities of 97.9-98.1%. Furthermore, the average nucleotide identities and digital DNA-DNA hybridization identities between the two isolates and other relatives were all less than 82.9 and 28.2 %, respectively, all below the species delineation thresholds. The results of pan-genomic analysis indicated that the type strain XJ19-10T shared 2813 core gene clusters with other three type strains of members of the genus Aquiflexum, as well as having 623 strain-specific clusters. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, an unidentified aminolipid and unidentified lipids. The predominant fatty acids (>10% of the total contents) were iso-C15 : 0, iso-C15 : 1G, iso-C17 : 0 3-OH and summed feature 9, and MK-7 was the respiratory quinone. On the basis of the results of phenotypic, physiological, chemotaxonomic and genotypic characterization, strains XJ19-10T and XJ19-11 are considered to represent a novel species, for which the name Aquiflexum gelatinilyticum sp. nov. is proposed. The type strain is XJ19-10T (=CGMCC 1.19385T =KCTC 92266T).

gcType: a high-quality type strain genome database for microbial phylogenetic and functional research.

Taxonomic and functional research of microorganisms has increasingly relied upon genome-based data and methods. As the depository of the Global Catalogue of Microorganisms (GCM) 10K prokaryotic type strain sequencing project, Global Catalogue of Type Strain (gcType) has published 1049 type strain genomes sequenced by the GCM 10K project which are preserved in global culture collections with a valid published status. Additionally, the information provided through gcType includes >12 000 publicly available type strain genome sequences from GenBank incorporated using quality control criteria and standard data annotation pipelines to form a high-quality reference database. This database integrates type strain sequences with their phenotypic information to facilitate phenotypic and genotypic analyses. Multiple formats of cross-genome searches and interactive interfaces have allowed extensive exploration of the database's resources. In this study, we describe web-based data analysis pipelines for genomic analyses and genome-based taxonomy, which could serve as a one-stop platform for the identification of prokaryotic species. The number of type strain genomes that are published will continue to increase as the GCM 10K project increases its collaboration with culture collections worldwide. Data of this project is shared with the International Nucleotide Sequence Database Collaboration. Access to gcType is free at http://gctype.wdcm.org/.

Devosia ureilytica sp. nov., isolated from Kuche River in China.

Two novel strains, designated XJ19-45T and XJ19-1, were isolated from water of Kuche River in Xinjiang Uygur Autonomous Region, China. Their cells were Gram-stain-negative, aerobic and motile rods. The phylogenetic analyses based on 16S rRNA genes and genomes showed that the two isolates belonged to the genus Devosia and the closest relative was Devosia subaequoris HST3-14T. The 16S rRNA genes sequences pairwise similarities, average nucleotide identities, digital DNA-DNA hybridizations and average amino acid identities between type strain XJ19-45T and other relatives were all less than 98.3, 80.3, 23.6 and 85.7 %, respectively, all below the species delineation thresholds. Pan-genomic analysis indicated that the novel isolate XJ19-45T shared 1594 core gene clusters with the 11 closely related type strains in Devosia, and the number of strain-specific clusters was 390. The major cellular fatty acids (>10 %) of the two isolates were summed feature 8, C18 : 1 ω7c 11-methyl and C16 : 0. Diphosphatidylglycerol, phosphatidylglycerol and glycolipids were the major polar lipids, and Q10 was the detected respiratory quinone. Based on the results of phenotypic, physiological, chemotaxonomic and genotypic characterizations, we propose that the isolates represent a novel species, for which the name Devosia ureilytica sp. nov. is proposed. The type strain is XJ19-45T (=CGMCC 1.19388T=KCTC 92263T).

Propioniciclava soli sp. nov., isolated from forest soil, Yunnan, China, and reclassification of the genus Brevilactibacter into the genus Propioniciclava, and Brevilactibacter sinopodophylli, Brevilactibacter flavus, and Brevilactibacter coleopterorum as Propioniciclava sinopodophylli comb. nov., Propioniciclava flava comb. nov., and Propioniciclava coleopterorum comb. nov., respectively.

A Gram-stain-positive, coccus-shaped, facultatively anaerobic, non-motile bacterial strain, designated YIM S02567T, was isolated from a forest soil sample collected from Gejiu City, Yunnan Province, southwest PR China. Growth was observed at 10-45 °C, at pH 6.0-9.5, in the presence of up to 4.0% (w/v) NaCl on R2A medium. The results of 16S rRNA gene sequence similarity analysis showed that strain YIM S02567T was most closely related to the type strain of Brevilactibacter sinopodophylli (95.4%) and Propioniciclava tarda (94.7%), and phylogenetic analysis based on genome data showed that strain YIM S02567T should be assigned to the genus Propioniciclava. The cell-wall diamino acid was meso-diaminopimelic acid. The major cellular fatty acids were identified as anteiso-C15:0 and C16:0, and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, and two unidentified glycolipids. The predominant menaquinone was MK-9(H4). The genomic DNA G + C content was 71.2 mol%. Based on the polyphasic taxonomic evidence, strain YIM S02567T is assigned to a novel member of the genus Propioniciclava, for which the name Propioniciclava soli sp. nov., (type strain YIM S02567T = CCTCC AB 2020128T = CGMCC 1.18504T = KCTC 49478T) is proposed. Furthermore, we propose the reclassification of Brevilactibacter as Propioniciclava gen. nov.

Roseomonas oleicola sp. nov., isolated from an oil production mixture in Yumen Oilfield, and emended description of Roseomonas frigidaquae.

A pink, ovoid-shaped, Gram-stain-negative, strictly aerobic and motile bacterial strain, designated ROY-5-3T, was isolated from an oil production mixture from Yumen Oilfield in PR China. The strain grew at 4-42 °C (optimum, 30 °C), at pH 5-10 (optimum, 7) and with 0-5 % (w/v) NaCl (optimum, 0%). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that ROY-5-3T belongs to the genus Roseomonas and shared the highest pairwise similarities with Roseomonas frigidaquae CW67T (98.1%), Roseomonas selenitidurans BU-1T (97.8%), Roseomonas tokyonensis K-20T (97.7%) and Roseomonas stagni HS-69T (97.3%). The average nucleotide identity and digital DNA-DNA hybridization values between ROY-5-3T and other related type strains of Roseomonas species were less than 84.08 and 28.60 %, respectively, both below the species delineation threshold. Pan-genomic analysis showed that the novel isolate ROY-5-3T shared 3265 core gene families with the four closely related type strains in Roseomonas, and the number of strain-specific gene families was 513. The major fatty acids were identified as summed feature 8 (C18 : 1 ω6c/C18 : 1 ω7c), summed feature 3 (C16 : 1 ω6c/C16 : 1 ω7c) and C16 : 0. Strain ROY-5-3T contained Q-10 as the main ubiquinone and the genomic DNA G+C content was 69.8 mol%. The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol. Based on the phylogenetic, morphological, physiological, chemotaxonomic and genome analyses, strain ROY-5-3T represents a novel species of the genus Roseomonas for which the name Roseomonas oleicola sp. nov. is proposed. The type strain is ROY-5-3T (=CGMCC 1.13459T =KCTC 82484T).

Pararhodonellum marinum gen. nov., sp. nov., isolated from deep-sea sediment.

A Gram-stain-negative, non-motile bacterial strain, designated SW124T, was isolated from a deep-sea sediment sample collected from the Indian Ocean. SW124T was aerobic and catalase-positive. The strain grew at 4-40 °C (optimum, 30 °C), at pH 5.0-8.6 (optimum, pH 7.0) and in the presence of 0.5-9.5 % (w/v) NaCl (optimum, 3.0%). The results of comparative analyses of the 16S rRNA gene sequence indicated that SW124T was grouped in the vicinity of the genus Rhodonellum in the family Cyclobacteriaceae. The quinone system contained menaquinone MK-7. The predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH and summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c). SW124T contained phosphatidylethanolamine (PE) as the major polar lipid. The genomic DNA G+C content of SW124T was 41.7 mol%. On the basis of its phenotypic characteristics and phylogenetic data, we propose that strain SW124T (=CGMCC 1.16171T=KCTC 82235T) represents a novel species of a novel genus, with the name Pararhodonellum marinum gen. nov., sp. nov.

Aliidiomarina indica sp. nov., isolated from deep seawater.

A Gram-stain-negative, rod-shaped bacterial strain, designated SW123T, was isolated from a deep-sea water sample collected from the Indian Ocean. Strain SW123T was strictly aerobic, catalase- and oxidase-positive. The predominant cellular fatty acids were iso-C15 : 0, iso-C17 : 0 and summed feature 9 (comprising C16 : 0-methyl or iso-C17 : 1 ω9c). Ubiquinone-8 was the sole respiratory quinone. The major polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The genomic DNA G+C content was 49.4 mol%. 16S rRNA gene sequence analysis showed that strain SW123T was closely related to Aliidiomarina shirensis AIST (96.7 % sequence similarity), Aliidiomarina iranensis GBPy7T (96.3%), Aliidiomarina haloalkalitolerans AK5T (96.0%) and Aliidiomarina celeris F3105T (95.9%). Phylogenetic trees based on 16S rRNA gene sequences showed that strain SW123T represented a novel member of the genus Aliidiomarina, forming a distinct cluster with A. celeris F3105T. On the basis of phylogenetic inference and phenotypic characteristics, we propose that strain SW123T represents a novel species of the genus Aliidiomarina, with the name Aliidiomarina indica sp. nov. The type strain is SW123T (=CGMCC1.16169T=KCTC 82234T).

Aurantimonas marina sp. nov., isolated from deep-sea sediment.

A novel bacterial strain, designated SW136T, was isolated from a deep-sea sediment sample collected from the South China Sea. Cells were Gram-stain-negative, aerobic, catalase-positive and oxidase-positive. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain SW136T represented a novel member of the genus Aurantimonas, forming a distinct cluster with 'Aurantimonas litoralis', Aurantimonas coralicida and Aurantimonas manganoxydans (98.2, 98.1 and 97.9% sequence similarity, respectively). The predominant cellular fatty acid of strain SW136T was C18 : 1 ω7c. Strain SW136T contained ubiquinone-10 as the dominant respiratory quinone, and diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine and phosphatidylglycerol as the major polar lipids. The genomic DNA G+C content was 64.3 mol%. The average nucleotide identity and digital DNA-DNA hybridization values of strain SW136T with A. coralicida CGMCC 1.12222T and A. manganoxydans CGMCC 1.12225T were 78.8 and 78.6 % and 21.5 and 25.5 %, respectively. On the basis of phylogenetic inference and phenotypic characteristics, we propose that strain SW136T represents a novel species of the genus Aurantimonas, with the name Aurantimonas marina sp. nov. The type strain is SW136T (=CGMCC 1.17725T=KCTC 82366T).

Undibacterium crateris sp. nov., isolated from water of crater lake.

A Gram-stain-negative, aerobic, flagellated, non-spore-forming, rod-shaped bacterium, named B2R-29T, was isolated from water collected from a crater lake on Da Hinggan mountain, PR China. Strain B2R-29T was oxidase- and catalase-positive. On the basis of the results of 16S rRNA gene sequence analyses, strain B2R-29T clearly belonged to the family Oxalobacteraceae, class Betaproteobacteria and showed the highest similarity to Undibacterium oligocarboniphilum EM1T (97.4 %) and to the other species of Undibacterium (less than 96.8 %). In the phylogenetic tree, strain B2R-29T formed a clade with U. oligocarboniphilum EM1T and Undibacterium squillarum CMJ-9T, indicating that is a member of the genus Undibacterium. Digital DNA-DNA hybridization and average nucleotide identity analyses were performed and the values between strain B2R-29T and its closely related Undibacterium species were less than 75.1 % and 16.9 %, respectively. The chemotaxonomic data of B2R-29T were as follows: major uniquinone, Q-8; predominant polar lipids, phosphatidylethanolamine, diphosphatidylglycerol and phosphatidylglycerol; major fatty acids, C16 : 0 and summed feature 3 (C16 : 1 ω7c / C16 : 1 ω6c); predominant polyamines, putrescine, 2-hydroxyputrescine and spermidine. The DNA G+C content was 51.7 mol% from the genomic sequencing data. In accordance with the phenotypic, physiological and chemotaxonomic properties mentioned above, strain B2R-29T represents a novel species of the genus Undibacterium for which the name Undibacterium crateris sp. nov. is proposed. The type strain is B2R-29T (=CGMCC 1.13792T=KCTC 72018T).

The potential co-benefits for health, economy and climate by substituting raw coal with waste cooking oil as a winter heating fuel in rural households of northern China.

The toxic emissions from coal combustion associated with domestic winter heating requirements are an important public health issue. Waste cooking oil (WCO) holds promise as a means of reducing pollutant emissions thereby improving human health with the co-benefit of decreasing climate-forcing gas emissions by avoiding the combustion of mineral coal. With an annual production of ~2.17 Mt of WCO in Northern China, it could be used to meet the winter heating demand of ~3.25 million rural households, offsetting ~9.83 Mt of raw coal consumption. Through the adoption of coal-to-WCO shift in rural regions of 15 provinces, approximately 15.0%, 15.6%, 15.9% and 13.7%, respectively of CO, PM2.5, SO2 and NOX emissions would be eliminated. It is estimated that such a change would remove the respective contributions of these pollutants to the premature deaths of respectively, 63,400, 29,300, 173,00 and 31,300 rural residents. Such a positive health impact on the labor cohort would reduce the loss of labor supply and work time, as well as producing billions of RMB in economic benefits. WCO-based heating technology has the same effect on the reduction of GWC100 value as other modern energy carriers while also being cheaper and sustainable, long term. Reducing household emissions by substituting raw coal with green energy is a vital strategy to support pathways for sustainable environment design. The results of this work for the coal-to-WCO shift can reinforce the support for coal phase-out in China.

Alkalibacillus aidingensis sp. nov., an Bacterium Isolated from Aiding Lake in Xinjiang Province, North-West China.

A bacterial strain, Gram staining negative, aerobic, long rod, motile bacterium with flagellum, designated strain YIM 98829T, was isolated from the Aiding Lake in Xinjiang province, North-West China. The isolate produced oval subterminal endospores in swollen sporangia. The predominant menaquinone was MK-7. The cell wall peptidoglycan contained ornithine, serine, aspartic acid, glutamic acid, and alanine, while diaminopimelic acid could not be detected. The major whole-cell sugars contained xylose, glucose, galactose, and mannose. Diphosphatidylglycerol, phosphatidylglycerol, one unknown phospholipid, and two unidentified aminophospholipids were part of the polar lipid profile. Iso-C15:0 and anteiso-C15:0 were the major fatty acids. The DNA G + C content of the type strain was 38.0 mol%. Phylogenetic analysis indicated that the isolate belongs to the genus Alkalibacillus. However, it differed from its closest relatives, A. haloalkaliphilus DSM 5271T (97.04%), A. filiformis 4AGT (96.99%), and A. silvisoli BM2T (96.95%) in some physiological characteristics. DNA-DNA hybridization result indicated low levels of relatedness between strain YIM 98829T and A. haloalkaliphilus JCM 12303T (16.9%). On the basis of physiological, phenotypic, and chemotaxonomic data, strain YIM 98829T represents a novel species of genus Alkalibacillus, for which the name Alkalibacillus aidingensis sp. nov. is proposed. The type strain is YIM 98829T (= NBRC 114103T = CGMCC 1.17260T = DSM 112470T).

Upgrading Solid Digestate from Anaerobic Digestion of Agricultural Waste as Performance Enhancer for Starch-Based Mulching Biofilm.

Developing a green and sustainable method to upgrade biogas wastes into high value-added products is attracting more and more public attention. The application of solid residues as a performance enhancer in the manufacture of biofilms is a prospective way to replace conventional plastic based on fossil fuel. In this work, solid digestates from the anaerobic digestion of agricultural wastes, such as straw, cattle and chicken manures, were pretreated by an ultrasonic thermo-alkaline treatment to remove the nonfunctional compositions and then incorporated in plasticized starch paste to prepare mulching biofilms by the solution casting method. The results indicated that solid digestate particles dispersed homogenously in the starch matrix and gradually aggregated under the action of a hydrogen bond, leading to a transformation of the composites to a high crystalline structure. Consequently, the composite biofilm showed a higher tensile strength, elastic modulus, glass transition temperature and degradation temperature compared to the pure starch-based film. The light, water and GHG (greenhouse gas) barrier properties of the biofilm were also reinforced by the addition of solid digestates, performing well in sustaining the soil quality and minimizing N2O or CH4 emissions. As such, recycling solid digestates into a biodegradable plastic substitute not only creates a new business opportunity by producing high-performance biofilms but also reduces the environmental risk caused by biogas waste and plastics pollution.

Phenotypic divergence of thermotolerance: Molecular basis and cold adaptive evolution related to intrinsic DNA flexibility of glacier-inhabiting Cryobacterium strains.

The link between guanine-cytosine (GC) content and thermal adaptation is controversial. Here, we compared maximum growth temperature (TMGT ) and genomics of 78 Cryobacterium strains to avoid unreliable conclusions resulting from distantly phylogenetic groups. Phylogenomic analysis revealed this taxon had much higher diversification than we knew. Interestingly, these strains showed thermotolerance divergence with phylogenetic cohesion. A significant difference was found between TMGT ≤ 20°C strains and TMGT > 20°C strains in genomic GC content which mainly caused by variation of GC3. TMGT ≤ 20°C strains tended to use synonymous codons ended with A/U, but TMGT > 20°C strains tended to use G/C. Lower GC content at synonymous sites (≈GC3) of TMGT ≤ 20°C strains could provide lower intrinsic DNA flexibility which strongly associated with optimal molecular dynamics, and then guarantee DNA function at lower growth temperatures. This analysis of codon bias revealed close relationships for thermal adaptation, GC content at synonymous sites (≈GC3), intrinsic DNA flexibility and optimal DNA dynamics. Natural selection was main force driving this codon bias; strains with lower TMGT endured stronger natural selection. Therefore, this study provided molecular basis for bacterial adaptive evolution from moderate temperature to low temperature.

Genomic characterization of closely related species in the Rumoiensis clade infers ecogenomic signatures to non-marine environments.

Members of the family Vibrionaceae are generally found in marine and brackish environments, playing important roles in nutrient cycling. The Rumoiensis clade is an unconventional group in the genus Vibrio, currently comprising six species from different origins including two species isolated from non-marine environments. In this study, we performed comparative genome analysis of all six species in the clade using their complete genome sequences. We found that two non-marine species, Vibrio casei and Vibrio gangliei, lacked the genes responsible for algal polysaccharide degradation, while a number of glycoside hydrolase genes were enriched in these two species. Expansion of insertion sequences was observed in V. casei and Vibrio rumoiensis, which suggests ongoing genomic changes associated with niche adaptations. The genes responsible for the metabolism of glucosylglycerate, a compound known to play a role as compatible solutes under nitrogen limitation, were conserved across the clade. These characteristics, along with genes encoding species-specific functions, may reflect the habit expansion which has led to the current distribution of Rumoiensis clade species. Genome analysis of all species in a single clade give us valuable insights into the genomic background of the Rumoiensis clade species and emphasize the genomic diversity and versatility of Vibrionaceae.

Craterilacuibacter sinensis gen. nov. sp. nov., isolated from a crater lake in China.

Two bacterial strains, designated B2N2-7T 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 B2N2-7T and B2N2-12 were assigned to the family Neisseriaceae, and their 16S rRNA gene sequences showed the highest similarities to that of Aquitalea denitrificans 5YN1-3T (<94.2 %). The predominant cellular fatty acids were C16 : 0 and summed feature 3 (comprising C16 : 1ω7c/C16 : 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 B2N2-7T 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 B2N2-7T (=CGMCC 1.17189T=KCTC 73735T); B2N2-12 (=CGMCC 1.17190=KCTC 72734) is a second strain of the species.

Cryobacterium ruanii sp. nov. and Cryobacterium breve sp. nov., isolated from glaciers.

Strains Sr36T and TMT4-23T were isolated from No. 1 glacier in Xinjiang Uygur Autonomous Region and Toumingmengke glacier in Gansu Province, PR China, respectively. They were Gram-stain-positive and rod-shaped micro-organisms. The optimum growth temperature of the two strains was 10-14 °C. Phylogenetic analysis showed that the two strains were related to members of the genus Cryobacterium. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain Sr36T and its close relatives Cryobacterium luteum Hh15T, Cryobacterium aureum Hh31T, Cryobacterium levicorallinum Hh34T and Cryobacterium flavum Hh8T were 81.16-87.24 and 28.0-32.5 %, respectively. The ANI and dDDH values between strain TMT4-23T and its close relative Cryobacterium psychrotolerans 0549T were 81.16 and 22.3 %. The polar lipids of strain Sr36T were diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid and three unidentified lipids. The polar lipids of strain TMT4-23T were diphosphatidylglycerol, phosphatidylglycerol, one unidentified glycolipid, one unidentified phospholipid and six unidentified lipids. The major fatty acids of strain Sr36T were anteiso-C15 : 0, iso-C16 : 0, anteiso-C17 : 0 and anteiso-C15 : 1. The major fatty acids of strain TMT4-23T were anteiso-C15 : 0, anteiso-C17 : 0, iso-C16 : 0, anteiso-C15 : 1 and iso-C15 : 1. Both strains contained 2,4-diaminobutyric acid and their predominant menaquinone was MK-10. On the basis of the phenotypic, phylogenetic and genotypic data, two novel species Cryobacterium ruanii sp. nov. (type strain = Sr36T=CGMCC 1.9275T=NBRC 113797T) and Cryobacterium breve sp. nov. (type strain =TMT4-23T=CGMCC 1.9556T=NBRC 113800T) are proposed.

Naganishia floricola sp. nov., a novel basidiomycetous yeast species isolated from flowers of Sorbaria sorbifolia.

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 6294T) and Naganishia antarctica (CBS 7687T). However, the new isolates differed from N. bhutanensis CBS 6294T 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 7687T. In the ITS region, the new isolates showed 1.15 % divergence (7 nt substitutions and one indel) to N. bhutanensis CBS 6294T and 0.92 % divergence (5 nt substitutions and no indels) to N. antarctica CBS 7687T. 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).