Aquariibacter albus gen. nov., sp. nov., a new member of the order Burkholderiales, isolated from a freshwater aquarium.

A novel bacterium, strain SJAQ100T, was isolated from a freshwater aquarium and was characterized taxonomically and phylogenetically. Strain SJAQ100T was a Gram-stain-negative, aerobic, rod-shaped and non-motile bacterium. The strain grew optimally with 0 % NaCl and at 25-37 °C on Reasoner's 2A agar. Phylogenetic analysis based on the 16S rRNA gene sequences revealed that the strain SJAQ100T clustered with members of Burkholderiales incertae sedis in the order Burkholderiales, but sequence similarities to known species were less than 96.5 %. The genomic DNA G+C content of strain SJAQ100T was 71.2 mol%. Genomic comparisons of strain SJAQ100T with species in the order Burkholderiales were made using the Genome-to-Genome Distance Calculator, average nucleotide identity and average amino acid identity analyses (values indicated ≤22.1, ≤78.1, and ≤68.1 % respectively). Strain SJAQ100T contained C16 : 0 and C16 : 1 ω7c/C16 : 1 ω6c as major fatty acids and Q-8 as the major quinone. The major polyamines were putrescine and cadaverine. Strain SJAQ100T contained phosphatidylethanolamine and diphosphatidylglycerol as major polar lipids. Based on the genotypic, chemotaxonomic and phenotypic results, strain SJAQ100T represents a novel genus and species, Aquariibacter albus gen. nov., sp. nov., which belongs to order Burkholderiales and the class Betaproteobacteria. The type strain is SJAQ100T (=KCTC 72203T=CGMCC 1.18869T=MCC 4385T).

Three cases of Sutterella wadsworthensis bacteremia secondary to abdominal infections.

The anaerobic bacterium Sutterella wadsworthensis has previously been isolated from the human intestine, both in healthy individuals and patients with gastrointestinal disorders, and the clinical significance of this bacterium is unknown. In this case report, we describe three cases of bacteremia with Sutterella wadsworthensis, from patients with recent intraabdominal surgery.

Potential hazardous effects of printing room PM2.5 exposure include promotion of lung inflammation and subsequent injury.

There have been few studies investigating the potential effects of indoor sources of particulate matter on human health. In this study, the effect of different concentrations of fine particulate matter (PM2.5) collected from a printing room on lung health was examined using cultured cells and a mouse model. Further, the mechanism of lung injury was examined. The results indicated that PM2.5 significantly enhanced malondialdehyde activity (P<0.05), decreased superoxide dismutase activity (P<0.05), upregulated the expression of pro­inflammatory factors including interleukin (IL)­1ß, tumor necrosis factor­, IL­6 and downregulated the expression of the inflammatory factor IL­2 (P<0.05). Western blot analysis indicated that PM2.5 significantly enhanced expression of phosphorylated (p)­ERK relative to total ERK, cyclooxygenase­2, p­anti­nuclear­factor­κB (p­NF­κB) relative to NF­κB, transforming growth factor­ß1 and Bax relative to Bcl­2 in inflammation (P<0.05), fibrosis and apoptosis signaling pathways. Furthermore, the results revealed that exposure was associated with an increased abundance of pathogens including Burkholderiales, Coriobacteriia, and Betaproteobacteria in in the lungs. In conclusion, exposure to PM2.5 from a printing room significantly increased inflammation, fibrosis, apoptosis and the abundance of pathogenic bacteria, indicating that exposure is potential threat to individuals who spend a significant amount of time in printing rooms.

Ideonella livida sp. nov., isolated from a freshwater lake.

A novel bacterial strain, designated TBM-1T, isolated from a freshwater lake in Taiwan, was characterized using a polyphasic taxonomic approach. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain TBM-1T formed a phylogenetic lineage in the genus Ideonella. Analysis of 16S rRNA gene sequences showed that strain TBM-1T was most closely related to Ideonella dechloratans CCUG 30898T with 98.4 % sequence similarity. The average nucleotide identity, average amino acid identity and digital DNA-DNA hybridization values between strain TBM-1T and closely related strains of the genus Ideonella were 74.4-77.5 %, 69.7-75.4 % and 19.8-21.8 %, respectively, supporting that strain TBM-1T represents a novel species of the genus Ideonella. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed blue colonies. Optimal growth occurred at 30 °C, pH 6 and 0 % NaCl. The predominant fatty acids of strain TBM-1T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two uncharacterized aminophospholipids and two uncharacterized phospholipids. The main polyamine was putrescine. The major isoprenoid quinone was Q-8. The estimated genome size was 5.26 Mb, with an average G+C content of 70.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain TBM-1T should be classified in a novel species of the genus Ideonella, for which the name Ideonella livida sp. nov. is proposed. The type strain is TBM-1T (=BCRC 81199T =LMG 31339T).

Network-directed efficient isolation of previously uncultivated Chloroflexi and related bacteria in hot spring microbial mats.

The perplexity of the complex multispecies community interactions is one of the many reasons why majority of the microorganisms are still uncultivated. We analyzed the entire co-occurrence networks between the OTUs of Tibet and Yunnan hot spring samples, and found that less abundant OTUs such as genus Tepidimonas (relative abundant <1%) had high-degree centricity (key nodes), while dominant OTUs particularly genus Chloroflexus (relative abundant, 13.9%) formed the peripheral vertexes. A preliminary growth-promotion assay determined that Tepidimonas sp. strain SYSU G00190W enhanced the growth of Chloroflexus sp. SYSU G00190R. Exploiting this result, an ameliorated isolation medium containing 10% spent-culture supernatant of Tepidimonas sp. strain SYSU G00190W was prepared for targeted isolation of Chloroflexi in the Tibet and Yunnan hot spring samples. 16S rRNA gene fingerprinting characterized majority of the colonies isolated from these media as previously uncultivated Chloroflexi, of which 36 are potential novel species (16S rRNA sequence identity <98.5%). Metabolomes studies indicated that the spent-culture supernatant comprises several low-molecular-weight organic substrates that can be utilized as potential nutrients for the growth of these bacteria. These findings suggested that limited knowledge on the interaction of microbes provide threshold to traditional isolation method.

Comparative genome sequence analysis of several species in the genus Tepidimonas and the description of a novel species Tepidimonas charontis sp. nov.

We performed high-quality genome sequencing of eight strains of the species of the genus Tepidimonas and examined the genomes of closely related strains from the databases to understand why Tepidimonas taiwanensis is the only strain of this genus that utilizes glucose and fructose for growth. We found that the assimilation of these hexoses by T. taiwanensis was due to the presence of two transporters that are absent in all other genomes of strains of members of the genus Tepidimonas examined. Some strains lack genes coding for glucokinase, but the Embden-Meyerhof-Parnas pathway appears to be otherwise complete. The pentose phosphate pathway has a complete set of genes, but genes of the Entner-Doudoroff pathway were not identified in the genomes of any of the strains examined. Genome analysis using average nucleotide identity (ANIb), digital DNA-DNA hybridization (dDDH), average amino acid identity (AAI) and phylogenetic analysis of 400 conserved genes was performed to assess the taxonomic classification of the organisms. Two isolates of the genus Tepidimonas from the hot spring at São Pedro do Sul, Portugal, designated SPSP-6T and SPSPC-18 were also examined in this study. These organisms are mixotrophic, have an optimum growth temperature of about 50 ºC, utilize several organic acids and amino acids for growth but do not grow on sugars. Distinctive phenotypic, 16S rRNA gene sequence and genomic characteristics of strains SPSP-6T and SPSPC-18 lead us to propose a novel species based on strain SPSP-6T for which we recommend the name Tepidimonas charontis sp. nov. (=CECT 9683T=LMG 30884T).

Aquabacterium lacunae sp. nov., isolated from a freshwater pond.

A novel bacterial strain, designated KMB7T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, motile by means of a single polar flagellum, rod-shaped and formed cream colonies. Optimal growth occurred at 25 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that strain KMB7T is affiliated with species in the genus Aquabacterium. The 16S rRNA gene sequence similarity indicated that strain KMB7T is closely related to species within the genus Aquabacterium (95.2-97.6 % sequence similarity) and is most similar to A. fontiphilum CS-6T (97.6 %), followed by A. parvum B6T (97.5 %). The average nucleotide identity and digital DNA-DNA hybridization identity between strain KMB7T and the closely related strains were 74.6-78.0 % and 19.0-21.2 %, respectively. The major fatty acids of strain KMB7T were summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c), C18 : 1 ω7c and C16 : 0. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, phosphatidylserine, diphosphatidylglycerol and four unidentified phospholipids. The sole isoprenoid quinone was ubiquinone-8 (Q-8). Genomic DNA G+C content of strain KMB7T was 65.4 %. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KMB7T should be classified in a novel species of the genus Aquabacterium, for which the name Aquabacterium lacunae sp. nov. is proposed. The type strain is KMB7T (=BCRC 81156T=LMG 30924T=KCTC 62867T).

Aquabacterium pictum sp. nov., the first aerobic bacteriochlorophyll a-containing fresh water bacterium in the genus Aquabacterium of the class Betaproteobacteria.

A strictly aerobic, bacteriochlorophyll a-containing betaproteobacterium, designated strain W35T, was isolated from a biofilm sampled at Tama River in Japan. The non-motile and rod-shaped cells formed pink-beige pigmented colonies on agar plates containing organic compounds, and showed an in vivo absorption maximum at 871 nm in the near-infrared region, typical for the presence of bacteriochlorophyll a. The new bacterial strain is Gram-negative, and oxidase- and catalase-positive. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain W35T was closely related to species in the genus Aquabacterium. The closest phylogenetic relatives of strain W35T were Aquabacterium commune B8T (97.9 % sequence similarity), Aquabacterium citratiphilum B4T (97.2 %) and Aquabacterium limnoticum ABP-4T (97.0 %). The major cellular fatty acids were C16  :  1ω7c (50.4 %), C16  :  0 (22.7 %), summed feature 8 (C18  :  1ω7c/C18  :  1ω6c; 9.7 %), C18  :  3ω6c (5.5 %), C12  :  0 (5.3 %) and C10  :  0 3OH (2.7 %). The respiratory quinone was ubiquinone-8. Predominant polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The G+C content of the genomic DNA was 70.4 mol% (genome data) and 71.4 mol% (HPLC). The genome size of strain W35T is 6.1 Mbp and average nucleotide identity analysis indicated genome similarities of strain W35T and related Aquabacterium type strains to be 78-79 %. The results of polyphasic comparisons showed that strain W35T was clearly distinguishable from other members of the genus Aquabacterium. Therefore, we propose a new species in the genus Aquabacterium, namely, Aquabacterium pictum sp. nov. The type strain is W35T (=DSM 106757T=NBRC 111963T). The description of the genus Aquabacterium is also emended.

Rubrivivax albus sp. nov., isolated from a freshwater pond.

Strain ICH-3T, isolated from a freshwater pond in Taiwan 9ROC), was characterized using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences and an up-to-date bacterial core gene set (92 protein clusters) indicated that ICH-3T is affiliated with the species in the genus Rubrivivax. ICH-3T was most closely related to Rubrivivax benzoatilyticus JA2T and Rubrivivax gelatinosus NCIB 8290T with 97.5 and 97.4 % 16S rRNA gene sequence similarity. The average nucleotide identity and digital DNA-DNA hybridization identity between ICH-3T and the two closely related strains were 77.3 and 20.9-21.0 %, respectively, indicating that ICH-3T represents a novel species of the genus Rubrivivax. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed white colonies. Optimal growth occurred at 30 °C, pH 7.5-8.0 and with 0.5 % NaCl. The major fatty acids (>20 %) of ICH-3T were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an uncharacterized aminophospholipid and two uncharacterized phospholipids. The major isoprenoid quinone was Q-8. The genomic DNA G+C content of ICH-3T was 70.3 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain ICH-3T should be classified as representing a novel species of the genus Rubrivivax, for which the name Rubrivivax albus sp. nov. is proposed. The type strain is ICH-3T (=BCRC 81155T=LMG 30930T=KCTC 62866T).

Pseudorivibacter rhizosphaerae gen. nov., sp. nov., isolated from rhizosphere soil of Camellia sinensis (L.) O. Ktze and emended description of the genus Rivibacter.

A Gram-stain-negative, facultative anaerobic, motile and straight rod-shaped bacterium, designated strain C1-9T, was isolated from rhizosphere soil of Camellia sinensis (L.) O. Ktze collected from a tea garden in Huize, south-western PR China. Cells were oxidase-positive and catalase-negative. Growth occurred at 20-40 °C and pH 6.0-10.0, with an optimal growth at 30 °C and pH 7.0. The respiratory quinone was detected as ubiquinone-8 (Q-8). The major fatty acids were identified as summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and summed feature 8 (C18 : 1ω7c or C18 : 1ω6c). The cellular polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, three unidentified phospholipids, two unidentified lipids, one unidentified aminophospholipid and one unidentified aminolipid. The polyamine types were detected as 1,8-diaminooctane and 2-hydroxyputrescine. The genomic DNA G+C content was 68.6 mol%. Based on the results of 16S rRNA gene sequence analysis, strain C1-9T (MF687442) showed highest sequence similarity to Rivibacter subsaxonicus DSM 19570T (97.1 %). The phylogenetic tree based on 16S rRNA gene sequences showed that strain C1-9T clustered close to R. subsaxonicus DSM 19570T, Methylibium petroleiphilum CCTCC AB 2014193T and species belonging to the genera Rhizobacter and Piscinibacter. The phylogenomic tree indicated that strain C1-9T formed a clade with R. subsaxonicus. The average nucleotide identity value was 76.0 % between strain C1-9T and R. subsaxonicus DSM 19570T, which is lower than the prokaryotic species delineation threshold of 95.0-96.0 %. The polyphasic taxonomic characteristics indicated that strain C1-9T represents a novel species of a new genus within the order Burkholderiales, for which the name Pseudorivibacter rhizosphaerae gen. nov., sp. nov. (type strain C1-9T = KCTC 62325T=CGMCC 1.13864T) is proposed.

Halotolerant Rhizobacterial Strains Mitigate the Adverse Effects of NaCl Stress in Soybean Seedlings.

BACKGROUND: Salinity is one of the major abiotic constraints that hinder health and quality of crops. Conversely, halotolerant plant growth-promoting rhizospheric (PGPR) bacteria are considered biologically safe for alleviating salinity stress. RESULTS: We isolated halotolerant PGPR strains from the rhizospheric soil of Artemisia princeps, Chenopodium ficifolium, Echinochloa crus-galli, and Oenothera biennis plants; overall, 126 strains were isolated. The plant growth-promoting traits of these isolates were studied by inoculating them with the soil used to grow soybean plants under normal and salt stress (NaCl; 200 mM) conditions. The isolates identified as positive for growth-promoting activities were subjected to molecular identification. Out of 126 isolates, five strains-Arthrobacter woluwensis (AK1), Microbacterium oxydans (AK2), Arthrobacter aurescens (AK3), Bacillus megaterium (AK4), and Bacillus aryabhattai (AK5)-were identified to be highly tolerant to salt stress and demonstrated several plant growth-promoting traits like increased production of indole-3-acetic acid (IAA), gibberellin (GA), and siderophores and increased phosphate solubilization. These strains were inoculated in the soil of soybean plants grown under salt stress (NaCl; 200 mM) and various physiological and morphological parameters of plants were studied. The results showed that the microbial inoculation elevated the antioxidant (SOD and GSH) level and K+ uptake and reduced the Na+ ion concentration. Moreover, inoculation of these microbes significantly lowered the ABA level and increased plant growth attributes and chlorophyll content in soybean plants under 200 mM NaCl stress. The salt-tolerant gene GmST1 was highly expressed with the highest expression of 42.85% in AK1-treated plants, whereas the lowest expression observed was 13.46% in AK5-treated plants. Similarly, expression of the IAA regulating gene GmLAX3 was highly depleted in salt-stressed plants by 38.92%, which was upregulated from 11.26% to 43.13% upon inoculation with the microorganism. CONCLUSION: Our results showed that the salt stress-resistant microorganism used in these experiments could be a potential biofertilizer to mitigate the detrimental effects of salt stress in plants via regulation of phytohormones and gene expression.

Comparison of infectious agents detected from hatchery and wild juvenile Coho salmon in British Columbia, 2008-2018.

Infectious diseases are potential contributors to decline in Coho salmon (Oncorhynchus kisutch) populations. Although pathogens are theoretically considered to pose higher risk in high-density rearing environments like hatcheries, there is no direct evidence that hatchery-origin Coho salmon increase the transmission of infectious agents to sympatric wild populations. This study was undertaken to compare prevalence, burden, and diversity of infectious agents between hatchery-reared and wild juvenile Coho salmon in British Columbia (BC), Canada. In total, 2,655 juvenile Coho salmon were collected between 2008 and 2018 from four regions of freshwater and saltwater in BC. High-throughput microfluidics qPCR was employed for simultaneous detection of 36 infectious agents from mixed-tissue samples (gill, brain, heart, liver, and kidney). Thirty-one agents were detected at least once, including ten with prevalence >5%. Candidatus Brachiomonas cysticola, Paraneuclospora theridion, and Parvicapsula pseudobranchiocola were the most prevalent agents. Diversity and burden of infectious agents were substantially higher in marine environment than in freshwater. In Mainland BC, infectious burden and diversity were significantly lower in hatchery smolts than in wild counterparts, whereas in other regions, there were no significant differences. Observed differences in freshwater were predominantly driven by three parasites, Loma salmonae, Myxobolus arcticus, and Parvicapsula kabatai. In saltwater, there were no consistent differences in agent prevalence between hatchery and wild fish shared among the west and east coasts of Vancouver Island. Although some agents showed differential infectious patterns between regions, annual variations likely contributed to this signal. Our findings do not support the hypothesis that hatchery smolts carry higher burdens of infectious agents than conspecific wild fish, reducing the potential risk of transfer to wild smolts at this life stage. Moreover, we provide a baseline of infectious agents in juvenile Coho salmon that will be used in future research and modeling potential correlations between infectious profiles and marine survival.

Inhella crocodyli sp. nov., isolated from a crocodile pond.

Strain CCP-18T, isolated from a freshwater pond in Taiwan, was characterized by using a polyphasic taxonomy approach. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain CCP-18T belongs to the genus Inhella and has the highest levels of sequence similarity with respect to Inhella inkyongensis IMCC1713T (98.9 %) and Inhella fonticola TNR-25T (98.0 %). Cells were Gram-stain-negative, aerobic, motile, rod-shaped and formed white-coloured colonies. Optimal growth occurred at 25 °C, pH 6 and in the absence of NaCl. The major fatty acids of strain CCP-18T were summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c) and C16 : 0. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, two unidentified aminophospholipids, an unidentified phospholipid, an unidentified aminolipid and an unidentified lipid. The predominant polyamine was putrescine. The major isoprenoid quinone was Q-8. The draft genome was approximately 3.76 Mb in size with a G+C content of 68.9 mol%. The DNA-DNA hybridization values for strain CCP-18Twith I.inkyongensis IMCC1713T and I.nhella fonticola TNR-25T were less than 40 %. Based on the phylogenetic and phenotypic data, strain CCP-18T should be classified within the genus Inhella as a representative of a novel species, named Inhella crocodyli sp. nov. The type strain is CCP-18T (=BCRC 81120T=LMG 30595T=KCTC 62511T).

Aquincola rivuli sp. nov., isolated from a freshwater stream.

Strain KYPY4T, isolated from a water sample taken from the Funglin stream in Taiwan, was characterized using a polyphasic taxonomic approach. The 16S rRNA gene sequence of strain KYPY4T was closely related to Ideonella dechloratans CCUG 30898T (97.1 %) followed by Aquincola tertiaricarbonis L10T (96.9 %) and Kinneretia asaccharophila KIN192T (96.8 %). Phylogenetic analyses based on 16S rRNA gene sequences showed that strain KYPY4T belonged to the genus Aquincola and formed a distinct phyletic line with A. tertiaricarbonis L10T and Aquincola amnicola TTM-94T. The draft genome of strain KYPY4T was approximately 4.93 Mb in size with a G+C content of 70.1 mol%. Strain KYPY4T showed 73.4-76.9 % average nucleotide identity and 21.3-22.5 % digital DNA-DNA hybridization identity with the strains of other related species in the Rubrivivax-Roseateles-Leptothrix-Ideonella-Aquabacterium group. Cells of strain KYPY4T were Gram-stain-negative, aerobic, motile, surrounded by a thick capsule and formed light orange colonies. Optimal growth occurred at 30 °C, pH 7 and 0 % NaCl. Strain KYPY4T contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), C16 : 0 and C18 : 1ω7c as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and several uncharacterized polar lipids. The major respiratory quinone was Q-8. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain KYPY4T should be classified as a novel species of the genus Aquincola, for which the name Aquincola rivuli sp. nov. is proposed. The type strain is KYPY4T (=BCRC 81010T=KCTC 52441T).

Defining the role of Parasutterella, a previously uncharacterized member of the core gut microbiota.

The genus of Parasutterella has been defined as a core component of the human and mouse gut microbiota, and has been correlated with various health outcomes. However, like most core microbes in the gastrointestinal tract (GIT), very little is known about the biology of Parasutterella and its role in intestinal ecology. In this study, Parasutterella was isolated from the mouse GIT and characterized in vitro and in vivo. Mouse, rat, and human Parasutterella isolates were all asaccharolytic and producers of succinate. The murine isolate stably colonized the mouse GIT without shifting bacterial composition. Notable changes in microbial-derived metabolites were aromatic amino acid, bilirubin, purine, and bile acid derivatives. The impacted bile acid profile was consistent with altered expression of ileal bile acid transporter genes and hepatic bile acid synthesis genes, supporting the potential role of Parasutterella in bile acid maintenance and cholesterol metabolism. The successful colonization of Parasutterella with a single environmental exposure to conventional adult mice demonstrates that it fills the ecological niche in the GIT and contributes to metabolic functionalities. This experiment provides the first indication of the role of Parasutterella in the GIT, beyond correlation, and provides insight into how it may contribute to host health.

Aquabacterium tepidiphilum sp. nov., a moderately thermophilic bacterium isolated from a hot spring.

A Gram-stain-negative, aerobic, non-spore-forming and rod-shaped bacterium, designated YIM 730274T, was isolated from a sediment sample collected from a hot spring located in Tibet, PR China, and was characterized by using a polyphasic taxonomy approach. Cells were motile by means of a polar flagellum. The strain was oxidase- and catalase-positive, and contained polyalkanoates and polyphosphate as storage polymers. Growth occurred at 25-50 °C, at pH 6.0-8.5 and with 0.5-1.0 % NaCl. The major fatty acids (>10 %) were summed feature 3 (C16 : 1ω6c and/or C16 : 1ω7c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C16 : 0. The known polar lipids comprised of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and phosphatidylserine. The isoprenoid quinone was Q-8. The G+C content of genomic DNA was 70.7 mol%. The results of phylogenetic analyses based on 16S rRNA gene sequences indicated that the strain forms a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Aquabacterium in the class Betaproteobacteria. The most closely related phylogenetic neighbours were Aquabacterium limnoticumABP-4T (97.8 % 16S rRNA gene sequence identity) and Aquabacterium communeB8T (97.2 % 16SrRNA gene sequence identity). DNA-DNA relatedness values between YIM 730274T and A. limnoticum KCTC 23306T (46.4±0.4 %) and A. commune DSM 11901T (42.2±1.2 %) were well below the 70 % limit for species identification. YIM 730274T was distinguishable from other members of the genus Aquabacterium by the differences in phenotypic, chemotaxonomic and genotypic characteristics. YIM 730274T merits recognition as a representative of a novel species of the genus Aquabacterium. It is proposed that the isolate should be classified in the genus Aquabacterium as representing a novel species, Aquabacteriumtepidiphilum sp. nov. The type strain is YIM 730274T (=KCTC 52716T=CCTCC AB 2016295T).

Mesosutterella multiformis gen. nov., sp. nov., a member of the family Sutterellaceae and Sutterella megalosphaeroides sp. nov., isolated from human faeces.

Two novel, obligately anaerobic, Gram-stain-negative, rod or coccoid-shaped bacteria, designated strains 4NBBH2T and 6FBBBH3T, were isolated from faecal samples of a healthy Japanese woman and man. The 16S rRNA gene sequence analysis showed that these strains represent a distinct lineage within the family Sutterellaceae. Strain 4NBBH2T formed a monophyletic branch between the genera Parasutterella and Sutterella, with sequence similarity to Sutterella stercoricanis CCUG 47620T (92.6 %), followed by Sutterella wadsworthensis WAL 7877 (92.4 %), Sutterella parvirubra YIT 11816T (92.1 %) and Parasutterella secunda YIT 12071T (91.8 %). Strain 6FBBBH3T was affiliated to the genus Sutterella, with highest similarity to S. stercoricanis CCUG 47620T (97.1 %), followed by S. parvirubra YIT 11816T (96.6 %) and S. wadsworthensis WAL 7877 (95.2 %). Strains 4NBBH2T and 6FBBBH3T were asaccharolytic. Analysis of fatty acids revealed that strain 4NBBH2T could be differentiated from Sutterella species (including strain 6FBBBH3T) by the presence of a low concentration of C16 : 1ω7c. The major respiratory quinones of strain 4NBBH2T were menaquinone (MK)-6 and methylmenaquinone (MMK)-6, whereas those of strain 6FBBBH3T were MK-5 and MMK-5. The G+C content of the genomic DNA of strains 4NBBH2T and 6FBBBH3T were 56.9 and 62.8 mol%, respectively. On the basis of the collected data, strain 4NBBH2T represents a novel species in a novel genus of the family Sutterellaceae, for which the name Mesosutterella multiformis gen. nov., sp. nov. is proposed. The type strain is 4NBBH2T (=JCM 32464T=DSM 106860T). We also propose a novel Sutterella species, Sutterellamegalosphaeroides sp. nov., for strain 6FBBBH3T (=JCM 32470T=DSM 106861T).

Draft genome sequence of Xenophilus sp. E41 isolated from an activated sludge reactor treating wastewater with high cephalexin concentration.

OBJECTIVES: This study reports the draft genome sequence of Xenophilus sp. E41, a strain resistant to multiple antimicrobials isolated from an activated sludge reactor treating wastewater with a high cephalexin concentration. METHODS: Genomic DNA of Xenophilus sp. E41 was extracted and sequenced using an Illumina NovaSeq 6000 system. The generated sequence reads were assembled using MEGAHIT in combination with SOAPdenovo. Mauve and CompareM were used to align the Xenophilus sp. E41 genome to other draft genomes of the genus Xenophilus in order to determine their evolutionary relationships. The draft genome was annotated using the Rapid Annotation using Subsystem Technology (RAST) server and the nr database, whilst antimicrobial resistance genes (ARGs) were identified using the SARG 2.0 database, RAST server and nr database. RESULTS: Xenophilus sp. E41, with a genome length of 5919552bp, harbours seven types of ARGs involving resistance to ß-lactams, tetracycline, aminoglycosides, sulfonamides, chloramphenicol, teicoplanin and bleomycin. No virulence factors or plasmids were identified. CONCLUSION: The genome sequence reported here will provide useful information for a better understanding of antimicrobial resistance profiles in this strain and the genus Xenophilus.

Soils associated to different tree communities do not elicit predictable responses in lake bacterial community structure and function.

Freshwater bacterioplankton communities are influenced by the inputs of material and bacteria from the surrounding landscape, yet few studies have investigated how different terrestrial inputs affect bacterioplankton. We examined whether the addition of soils collected under various tree species combinations differentially influences lake bacterial communities. Lake water was incubated for 6 days following addition of five different soils. We assessed the taxonomic composition (16S rRNA gene sequencing) and metabolic activity (Biolog Ecoplates) of lake bacteria with and without soil addition, and compared these to initial soil communities. Soil bacterial assemblages showed a strong influence of tree composition, but such community differences were not reflected in the structure of lake communities that developed during the experiment. Bacterial taxa showing the largest abundance increases during incubation were initially present in both lake water and across most soils, and were related to Cytophagales, Burkholderiales and Rhizobiales. No clear metabolic profiles based on inoculum source were found, yet soil-amended communities used 60% more substrate than non-inoculated communities. Overall, we show that terrestrial inputs influence aquatic communities by stimulating the growth and activity of certain ubiquitous taxa distributed across the terrestrial-aquatic continuum, yet different forest soils did not cause predictable changes in lake bacterioplankton assemblages.

Piscinibacter caeni sp. nov., isolated from activated sludge.

A yellowish-pigmented bacterial strain, designated as MQ-18T, was isolated from a sample of activated sludge collected from a pharmaceutical factory in Zhejiang, China. The strain was characterized through a polyphasic taxonomy approach. 16S rRNA gene sequence analysis demonstrated that strain MQ-18T showed high similarities to Piscinibacter defluvii SH-1T (99.7 %) and Piscinibacter aquaticus IMCC1728T (98.4 %), thereby suggesting that it belongs to the genus Piscinibacter. The DNA-DNA relatedness values of this strain to strains SH-1T and IMCC1728T were only 35.4 and 33.3 %, respectively. Cells of MQ-18T were Gram-negative, aerobic, motile, rod-shaped and non-spore forming. This strain exhibited growth at 25-37 °C (optimum: 30 °C) in the presence of 0-3.0 % (w/v) NaCl (optimum, 0 % NaCl) and at pH 5.0-8.0 (pH 7.0). The predominant fatty acids were C12 : 0 (5.5 %), C16 : 0 (33.7 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 38.5 %), and summed feature 4 (anteiso-C17 : 1 B and/or iso C17 : 1 I; 11.6 %). The main quinone type was ubiquinone-8, and the major polyamines were cadaverine and putrescine. The major polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The DNA G+C content was 70.1 mol%. On the basis of its phylogenetic, phenotypic and physiological characteristics, strain MQ-18T is considered to represent a novel species of the genus Piscinibacter, for which the name Piscinibacter caeni sp. nov. is proposed. The type strain is MQ-18T (CCTCC AB 2017223T=JCM 32138T).