New insights into the typical nitrogen-containing heterocyclic compound-quinoline degradation and detoxification by microbial consortium: Integrated pathways, meta-transcriptomic analysis and toxicological evaluation

As the primary source of COD in industrial wastewater, quinoline has aroused increasing attention because of its potential teratogenic, carcinogenic, and mutagenic effects in the environment. The activated sludge isolate quinoline-degrading microbial consortium (QDMC) efficiently metabolizes quinoline. However, the molecular underpinnings of the degradation mechanism of quinoline by QDMC have not been elucidated. High-throughput sequencing revealed that the dominant genera included Diaphorobacter, Bacteroidia, Moheibacter and Comamonas. Furthermore, a positive strong correlation was observed between the key bacterial communities (Diaphorobact and Bacteroidia) and quinoline degradation. According to metatranscriptomics, genes associated with quorum sensing, ABC transporters, component systems, carbohydrate, aromatic compound degradation, energy metabolism and amino metabolism showed high expression, thus improving adaptability of microbial community to quinoline stress. In addition, the mechanism of QDMC in adapting and resisting to extreme environmental conditions in line with the corresponding internal functional properties and promoting biogegradation efficiency was illustrated. Based on the identified products, QDMC effectively mineralized quinoline into low-toxicity metabolites through three major metabolic pathways, including hydroxyquinoline, 1,2,3,4-H-quinoline, 5,6,7,8-tetrahydroquinoline and 1-oxoquinoline pathways. Finally, toxicological, genotoxicity and phytotoxicity studies supported the detoxification of quinoline by the QDMC. This study provided a promising approach for the stable, environmental-friendly and efficient bioremediation applications for quinoline-containing wastewater.

Description and genome-wide analysis of Profundicola chukchiensis gen. nov., sp. nov., marine bacteria isolated from bottom sediments of the Chukchi Sea

Two Gram-negative, aerobic halophilic non-motile strains designated KMM 9713 and KMM 9724T were isolated from the bottom sediments sampled from the Chukchi Sea in the Arctic Ocean, Russia. The novel strains grew in 0.5-5% NaCl, at 7-42°C, and pH 5.5-10.5. Phylogenetic analyses based on 16S rRNA gene and whole genome sequences revealed that strains KMM 9713 and KMM 9724T were close to each other and shared the highest 16S rRNA gene sequence similarity of 91.28% with the type strain Ornithobacterium rhinotracheale DSM 15997T and 90.15-90.92% with the members of the genus Empedobacter in the family Weeksellaceae. Phylogenetic trees indicated that strains KMM 9713 and KMM 9724T formed a distinct line adjacent to their relative O. rhinotracheale DSM 15997T. The average nucleotide identity values between strain KMM 9724T and O. rhinotracheale DSM 15997T, Empedobacter brevis NBRC 14943T, and Moheibacter sediminis CGMCC 1.12708T were 76.73%, 75.78%, and 74.65%, respectively. The novel strains contained the predominant menaquinone MK-6 and the major fatty acids of iso-C17:0 3-OH, iso-C15:0 followed by iso-C17:1ω6. Polar lipids consisted of phosphatidylethanolamine, one an unidentified aminophospholipid, two unidentified aminolipids, and two or three unidentified lipids. The DNA G+C contents of 34.5% and 34.7% were calculated from genome sequence of the strains KMM 9713 and KMM 9724T, respectively. Based on the phylogenetic evidence and distinctive phenotypic characteristics, strains KMM 9713 and KMM 9724T are proposed to be classified as a novel genus and species Profundicola chukchiensis gen. nov., sp. nov. The type strain of Profundicola chukchiensis gen. nov., sp. nov. is strain KMM 9724T (= KACC 22806T).

Enhancement and mechanisms of micron-pyrite driven autotrophic denitrification with different pretreatments for treating organic-limited waters

Pyrite-driven autotrophic denitrification (PAD) represents a cheap and promising way for nitrogen removal from organic-limited wastewater, which has obtained increasing attention in recent years. However, the limited denitrification rate and unclear mechanism underlying the process have hindered the engineered application of PAD. This study aims to shed light on the impacts of different pretreatments (i.e., ultrasonication, acid-washing and calcination) on micron-pyrite surface characteristics, denitrification performance and biofilm formation during PAD in batch reactors. A series of solid-phase analyses revealed that all pretreatments could significantly promote biofilm attachment on pyrite granules, but impacted the proportion, distribution and chemical oxidation state of sulfur (S) and iron (Fe) at varying degrees. Batch tests showed that ultrasonication and acid-washing could enhance the total nitrogen reduction rate by 14% and 99%, and decrease the sulfate production rate by 51% and 42%, respectively, when compared with untreated pyrite. Microbial community analysis indicated that Thiobacillus and Rhodanobacter dominated in PAD systems. Two types of indirect mechanisms (i.e., contact and non-contact) for pyrite leaching may co-occur in PAD system, resulting in ferrous iron (Fe²⁺), thiosulfate (S₂O₃^2-) and sulfide (S^2-) as the main electron donors for denitrification. A PAD mechanism model was proposed to describe the PAD electron transfer pathway with the aim to optimize the engineered application of PAD for nitrogen removal.

Microflora for improving the Auricularia auricula spent mushroom substrate for Protaetia brevitarsis production

Mushroom cultivation is a sustainable agricultural waste utilization method, but the lack of high-value utilization of the produced spent mushroom substrate (SMS) has hindered the development of mushroom cultivation-based circular agricultural systems. Conversion and utilization of SMS via Protaetia brevitarsis larvae (PBL) have proven to be a high-value AASMS utilization strategy. However, Auricularia auricula SMS (AASMS), which contains woodchips, is less palatable and digestible for PBL. To solve this problem, in this investigation, we screened out microflora (MF) for AASMS fermentation by comparing the fermentation performance as well as the effect on PBL feed intake, weight gain, and AASMS phytotoxic compound removal efficiency. In addition, by bacterial community analysis, the genera Luteimonas, Moheibacter, and Pseudoxanthomonas were predicted to be functional bacteria for AASMS fermentation and contribute to palatability and digestibility improvement.

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Larvae frass microflora can ferment Auricularia auricula spent mushroom substrate

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The fermentation can improve feed intake, weight gain, and phytotoxic removal efficiency

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The genera Luteimonas, Moheibacter, and Pseudoxanthomonas were functional bacteria

Faecalibacter bovis sp. nov., isolated from cow faeces

A Gram-stain-negative, non-spore-forming, yellow-pigmented, aerobic, pleomorphic rod-shaped bacterium, designated ZY171143^T, was isolated from faeces of a cow with diarrhoea in Wenshan, Yunnan Province, south-west China and its taxonomic position was studied. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain ZY171143^T belonged to the family Weeksellaceae and was most closely related to the only species of the genus Faecalibacter, Faecalibacter macacae CCTCC AB 2016016^T with a sequence similarity of 97.8 %. The genomic OrthoANI and digital DNA-DNA hybridization values between the strain and F. macacae CCTCC AB 2016016^T were 86.2 and 30.5 %, respectively. The genomic G+C content was 31.1 mol%. The predominant fatty acids (>5 %) were C_15 : 0 iso, C_17 : 0 iso 3OH, C_16 : 0, C_16 : 1ω5c and summed feature 3 (C_16 : 1ω7c and/or 16 : 1 ω6c). The major polar lipids were phosphatidylethanolamine, triacylglycerol and sulfonolipid. The sole respiratory quinone was MK-6. These chemotaxonomic characterizations also revealed that strain ZY171143^T was a member of the genus Faecalibacter. Based on the phenotypic, chemotaxonomic and genotypic data, strain ZY171143^T represents a novel species within the genus Faecalibacter, for which the name Faecalibacter bovis sp. nov. is proposed. The type strain is ZY171143^T (=CGMCC 1.13663^T=KCTC 62642^T).

Simultaneous mineralization of 2-anilinophenylacetate and denitrification by Ru/Fe modified biocathode double-chamber microbial fuel cell

A double-chamber microbial fuel cell (MFC) with Ru/Fe-modified-biocathode was constructed for simultaneous mineralization of 2-anilinophenylacetate (APA) and denitrification. The factors on performance of simultaneous APA degradation and denitrification were explored. The contributions of ROS to APA degradation were evaluated by EPR and quenching experiments. The microbial community of Ru/Fe-modified-biocathode was determined by high-throughput sequencing. Results showed that low resistance accelerated APA degradation by Ru/Fe-modified-biocathode, while higher initial APA concentration inhibited microbial activity of the biocathode. The optimum ammonia concentration was 50 mg L^-1, while too high or too low ammonia concentration did not favor APA degradation. The APA degradation efficiency of Ru/Fe-modified-biocathode-MFC was higher than that of other modified-cathode-MFCs. The APA degradation process confirmed to the pseudo-first-order kinetic model, and APA degradation kinetic constant, the maximum removal efficiency of TOC, ammonia and TN were 2.15d^-1, 59.70%, 99.20% and 44.56% respectively, signifying a simultaneous APA mineralization and denitrification performance of Ru/Fe-modified-biocathode-MFC. The coulombic efficiency decreased with APA concentration increase. OH was the primary radical in APA degradation progress. Eight kinds of intermediates were measured, and two APA degradation pathways were proposed, among which APA hydroxylation was the main pathway. The microbial community of Ru/Fe-modified-biocathode was dominated with Nitrosomonas at genus level, and enriched with various APA-degraders, nitrifiers, and denitrifiers such as Pseudomonas, Nitrospira, Nitrobacter, Paracoccus, Thermomonas, Dechloromonas, and Clostridium_Sutra_stricto_1. COG analysis showed the redox reaction of Ru/Fe might affect signal transduction and environment adaptation, while FAPROTAX analysis suggested that Ru/Fe-modified-biocathode exhibited higher nitrification activity than that of carbon-felt-biocathode. The synergistic mechanism of simultaneous APA mineralization and denitrification was mainly redox reaction of Ru/Fe and supplemented by aerobic biodegradation.

Drivers and ecological consequences of arsenite detoxification in aged semi-aerobic landfill

Microbial populations responsible for arsenite [As(III)] detoxification were examined in aged refuse treated with 75 μM As(III) under semi-aerobic conditions. As(III) was rapidly oxidized to As(V) via microbial activity, and substantial As was fixed in the solid phase. The abundance of arsenite oxidase genes (aioA) was about four times higher in the moderate As(III) stressed treatment than in the untreated control. Network analysis of microbial community 16S rRNA genes based on MRT (random matrix theory) further illuminated details about microbe-microbe interactions, and showed six ecological clusters. A total of 166 "core" taxa were identified by within-module connectivity and among-module connectivity values. When compared with the control treatment without As(III), 12 putative keystone operational taxonomic units were positively correlated with As(III) oxidation, of which 10 of these were annotated to genera level. Eight genera were associated with As(III) detoxification: Pseudomonas, Paenalcaligenes, Proteiniphilum, Moheibacter, Mobilitalea, Anaerosporobacter, Syntrophomonas and Pusillimonas. Most of those putative keystone taxa were rare species in landfill, which suggests that low-abundance taxa might significantly contribute to As(III) oxidation.

Moheibacter lacus sp. nov., Isolated from Freshwater Lake Sediment

A Gram-stain-negative, yellow-pigmented, rod-shaped, strictly aerobic, non-motile bacterium, designated BDHS18^T, was isolated from the sediment of the Hasuhai Lake, China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that this strain belongs to the genus Moheibacter in the family Flavobacteriaceae and its closest relative was Moheibacter sediminis JCM 19634^T (96.0%), followed by Moheibacter stercoris DSM 29388^T (95.3%). Cells of strain BDHS18^T were catalase-positive and oxidase-negative. Strain BDHS18^T was found to grow optimally at 28-33 ℃, pH 7.5-8.0, and in the presence of approximately 1.0% (w/v) NaCl. Major cellular fatty acids were iso-C_15:0, iso-C_17:0 3-OH, Summed feature 4 and Summed feature 9. The predominant respiratory quinone was MK-6. The predominant polar lipids in strain BDHS18^T were phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminolipid and one unidentified lipid. The DNA G + C content was 36.9 mol%. According to the phylogenetic analysis, physiological and phenotypic characteristics, strain BDHS18^T represents a novel species of the genus Moheibacter, for which the name Moheibacter lacus sp. nov. is proposed. The type strain is BDHS18^T (= KCTC 72160^T = MCCC 1H00369^T).

Reservoir water stratification and mixing affects microbial community structure and functional community composition in a stratified drinking reservoir

To investigate how the aquatic bacterial community of a stratified reservoir drives the evolution of water parameters, the microbial community structure and network characteristics of bacteria in a stratified reservoir were investigated using Illumina MiSeq sequencing technology. A total of 42 phyla and 689 distinct genera were identified, which showed significant seasonal variation. Additionally, stratified variations in the bacterial community strongly reflected the vertical gradient and seasonal changes in water temperature, dissolved oxygen, and nutrition concentration. Furthermore, principal coordinate analysis indicated that most microorganisms were likely influenced by changes in water stratification conditions, exhibiting significant differences during the stratification period and mixing period based on Adonis, MRPP, and Anosim. Compared to the stratification period, 123 enhanced operational taxonomic units (OTUs; 29%) and 226 depleted OTUs (52%) were identified during the mixing period. Linear discriminant analysis effect size results showed that 15 major genera were enriched in the mixing period and 10 major genera were enriched in the stratification period. Importantly, network analysis revealed that the keystone species belonged to hgcI_clade, CL500-29, Acidibacter, Paucimonas, Flavobacterium, Prochlorothrix, Xanthomonadales, Chloroflexia, Burkholderiales, OPB56, KI89A_clade, Synechococcus, Caulobacter or were unclassified. Redundancy analysis showed that temperature, dissolved oxygen, pH, chlorophyll-α, total phosphorus, nitrate, and ammonia were important factors influencing the water bacterial community and function composition, which were consistent with the results of the Mantel test analysis. Furthermore, random forest analysis showed that temperature, dissolved oxygen, ammonia, and total dissolved phosphorous were the most important variables predicting water bacterial community and function community α- and β-diversity (P < 0.05). Overall, these results provide insight into the interactions between the microbial community and water quality evolution mechanism in Zhoucun reservoir.

Metabolic function, trophic mode, organics degradation ability and influence factor of bacterial and fungal communities in chicken manure composting

The metabolic function and organic degradation behavior of bacterial and fungal communities were detected in 60 days composting of chicken manure and pumice by using Biolog tools, PICRUSt and FUNGuild. Fungal diversity increased from 57 OTUs in fresh chicken manure to 109 OTUs in high temperature stage, while bacterial diversity decreased from 86 OTUs to 44 OTUs after composting treatment. The carbohydrates degradation ability of bacterial community was enhanced in the high temperature stage. Fungal community had relatively higher degradation rates of carboxylic acids and amino acids in the maturation stage. Saprotroph was the main trophic mode of fungal community during the incubation process. The fungal animal pathogen decreased from 12.5% to 1.2% after composting treatment. Bacterial community composition and substrates degradation rate were mainly influenced by redox potential, pH and moisture, while temperature was the main environmental factor influencing on organic degradation of fungal community.

Unraveling interactive characteristics of microbial community associated with bioelectric energy production in sludge fermentation fluid-fed microbial fuel cells

This first-attempt study deciphered the interactive characteristics of anodophilic microbial community-associated bioelectricity production in waste activated sludge (WAS) fermentation fluid-fed microbial fuel cells (MFCs). A novel schematic elucidation for illustrating synergistic interactions in anodic microbial consortia towards electrogenesis was proposed. Moreover, the specific genera of Pseudomonas, Desulfovibrio, Phyllobacterium, Desulfuromonas, Chelatococcus and Aminivibrio were dominant in anodic biofilms, leading to an electrogenesis efficiency of 1.254 kWh/kg COD and peak power density of 0.182 W/m² (at feeding level of 1.20 g COD/L). It was apparently higher than those MFCs fed with glucose/acetate. The fermentative species contributed positively in reorganizing microbial community structure in anodic biofilms, positively relating to electrogenesis via interactions with exoeletrogens in MFCs. Finally, a more electrogenesis was positively associated to larger anodic microbial diversity, relatively medium anodic community evenness, together with higher abundance of functional genes related to electrogenesis in functional species in MFCs fed with WAS fermentation fluid.

Analysis of 1,000 Type-Strain Genomes Improves Taxonomic Classification of Bacteroidetes

Although considerable progress has been made in recent years regarding the classification of bacteria assigned to the phylum Bacteroidetes, there remains a need to further clarify taxonomic relationships within a diverse assemblage that includes organisms of clinical, piscicultural, and ecological importance. Bacteroidetes classification has proved to be difficult, not least when taxonomic decisions rested heavily on interpretation of poorly resolved 16S rRNA gene trees and a limited number of phenotypic features. Here, draft genome sequences of a greatly enlarged collection of genomes of more than 1,000 Bacteroidetes and outgroup type strains were used to infer phylogenetic trees from genome-scale data using the principles drawn from phylogenetic systematics. The majority of taxa were found to be monophyletic but several orders, families and genera, including taxa proposed long ago such as Bacteroides, Cytophaga, and Flavobacterium but also quite recent taxa, as well as a few species were shown to be in need of revision. According proposals are made for the recognition of new orders, families and genera, as well as the transfer of a variety of species to other genera. In addition, emended descriptions are given for many species mainly involving information on DNA G+C content and (approximate) genome size, both of which can be considered valuable taxonomic markers. We detected many incongruities when comparing the results of the present study with existing classifications, which appear to be caused by insufficiently resolved 16S rRNA gene trees or incomplete taxon sampling. The few significant incongruities found between 16S rRNA gene and whole genome trees underline the pitfalls inherent in phylogenies based upon single gene sequences and the impediment in using ordinary bootstrapping in phylogenomic studies, particularly when combined with too narrow gene selections. While a significant degree of phylogenetic conservation was detected in all phenotypic characters investigated, the overall fit to the tree varied considerably, which is one of the probable causes of misclassifications in the past, much like the use of plesiomorphic character states as diagnostic features.

Empedobacter tilapiae sp. nov., isolated from an intestine of Nile tilapia (Oreochromis niloticus)

A Gram-stain-negative, aerobic, non-motile and ovoid or rod-shaped bacterial strain, MRS2^T, was isolated from an intestine of Nile tilapia (Oreochromisniloticus) collected from the Republic of Korea. Strain MRS2^T grew optimally at 30 °C and in the presence of 0-2.0 % (w/v) NaCl. A neighbour-joining phylogenetic tree of 16S rRNA gene sequences showed that strain MRS2^T clustered with the type strains of Empedobacter species. It exhibited the highest 16S rRNA gene sequence similarity (98.5 %) to the type strain of Empedobacter falsenii and sequence similarities of 97.4-97.6 % to the type strains of two other Empedobacter species. Strain MRS2^T contained MK-6 as the predominant ubiquinone and summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c), iso-C_17 : 0 3-OH and iso-C_15 : 0 as the major fatty acids. The major polar lipids of strain MRS2^T were phosphatidylethanolamine, one unidentified lipid and one unidentified aminolipid. The DNA G+C contents of strain MRS2^T were 32.2 mol% or 30.65 mol%. Strain MRS2^T exhibited DNA-DNA relatedness values of 12-20 % to the type strains of Empedobacter falsenii, Empedobacter brevis and Empedobacter stercoris. The average nucleotide identity values between strain MRS2^T and five strains of E. falsenii and E. brevis were 84.8-91.0 %. The phylogenetic, genetic and differential phenotypic properties indicated that strain MRS2^T is separated from Empedobacter species. On the basis of the data presented here, strain MRS2^T is considered to represent a novel species of the genus Empedobacter, for which the name Empedobactertilapiae sp. nov. is proposed. The type strain is MRS2^T (=KCTC 62904^T=NBRC 113550^T).

Insights into microbial community profiles associated with electric energy production in microbial fuel cells fed with food waste hydrolysate

Insights of microbial community profiles associated with electric energy production in microbial fuel cells (MFCs) fed with food waste hydrolysate (FWH) were investigated in this study. High power density of 0.173 W/m² was obtained from FWH which was produced from food waste after the pretreatment with fungal mash at an influent COD concentration of 1.2 g/L. The main genera in the MFCs fed with FWH were found to be Rummeliibacillus, Burkholderia, Enterococcus and Clostridium in anodic biofilms, leading to an electrogenesis efficiency of 0.977 kWh/kg COD higher than those obtained in MFCs with single carbon source feed. The key members in the anodic community responsible for electrogenesis were conceptually identified with their metabolic interactions in MFCs fed with FWH. It appeared that the syntrophic cooperation of fermentative species with exoelectrogens played an essential role in the generation of electric energy via specific microbes in anodic biofilm. The power produced from FWH was positively associated with microbial diversity, intermediate community evenness and abundance of functional genes for bioelectrogenesis.

Bacterial community shift and antibiotics resistant genes analysis in response to biodegradation of oxytetracycline in dual graphene modified bioelectrode microbial fuel cell

This study explored the biodegradation mechanisms of oxytetracycline (OTC/O) and electrochemical characteristics from the perspective of bacterial community shift and OTC resistance genes in dual graphene modified bioelectrode microbial fuel cell (O-D-GM-BE MFC). In phylum level, Proteobacteria was accounted to 95.04% in O-GM-BA, Proteobacteria and Bacteroidetes were accounted to 59.13% and 20.52% in O-GM-BC, which were beneficial for extracellular electron transport (EET) process and OTC biodegradation. In genus level, the most dominant bacteria in O-GM-BA were Salmonella and Trabulsiella, accounting up to 83.04%, moreover, representative exoelectrogens (Geobacter) were enriched, which contributed to OTC biodegradation and electrochemical performances; abundant degrading bacteria (Moheibacter, Comamonas, Pseudomonas, Dechloromonas, Nitrospira, Methylomicrobium, Pseudorhodoferax, Thiobacillus, Mycobacterium) were enriched in O-GM-BC, which contributed to the maximum removal efficiency of OTC; coding resistance genes of efflux pump, ribosome protective protein and modifying or passivating were all found in O-GM-BE, and this explained the OTC removal mechanisms from gene level.

Biodegradation of oxytetracycline and electricity generation in microbial fuel cell with in situ dual graphene modified bioelectrode

A three-step method to prepare dual graphene modified bioelectrode (D-GM-BE) in microbial fuel cell (MFC) in previous studies. This study explored the biodegradation of oxytetracycline (OTC) and electricity generation in O-D-GM-BE MFC. The OTC removal efficiency of graphene modified biocathode and bioanode (O-GM-BC, O-GM-BA) was 95.0% and 91.8% in eight days. The maximum power density generated by O-D-GM-BE MFC was 86.6 ± 5.1 mW m^-2, which was 2.1 times of that in OTC control bioelectrode (O-C-BE) MFC. The Rct of O-GM-BA and O-GM-BC were decreased significantly by 78.3% and 76.3%. OTC was biodegraded to monocyclic benzene compounds by bacteria. O-GM-BA was affected strongly by OTC, and Salmonella and Trabulsiella were accounted for 83.0%, while typical exoelectrogens (Geobacter) were still enriched after the maturity of biofilm. In O-GM-BC, bacteria related with OTC biodegradation (Comamonas, Ensifer, Sphingopyxis, Pseudomonas, Dechloromonas, etc.) were enriched, which contributed to the high removal efficiency of OTC.

Sphingomonas floccifaciens sp. nov., isolated from subterranean sediment

A Gram-stain-negative, non-motile, non-sporulating, rod-shaped, orange-pigmented bacterium, designated strain FQM01^T, was isolated from a subterranean sediment sample in the Mohe permafrost area, China. Strain FQM01^T grew optimally at 25 °C, pH 7.0 and NaCl concentration of 0 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FQM01^T belonged to the genus Sphingomonas. The closest phylogenetic relative was Sphingomonas spermidinifaciens GDMCC 1.657^T (97.6 %), followed by Sphingomonas mucosissima DSM 17494^T (97.2 %). The DNA G+C content of the isolate was 66.9 mol%. Strain FQM01^T contained Q-10 as the predominant ubiquinone, and C18 : 1ω6c and/or C18 : 1ω7c, C16 : 1ω6c and/or C16 : 1ω7c, C16 : 0, C14 : 0 2-OH and C18 : 1ω7c 11 methyl as the major fatty acids. Major polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid and an unidentified glycolipid. Only sym-homospermidine was detected as the polyamine. On the basis of phylogenetic and phenotypic data, strain FQM01^T is considered to represent a novel species of Sphingomonas for which the name Sphingomonasfloccifaciens sp. nov. is proposed. The type strain is FQM01^T (=CGMCC 1.15797^T=KCTC 52630^T).

Flavobacterium limi sp. nov., isolated from forest mud

A Gram-stain-negative, aerobic, non-motile, yellow and rod-shaped bacterial strain was isolated from forest mud located at Kyung Hee University, South Korea. Strain THG-AG6.4^T grew at 10-35 °C, pH 6.0-9.5 and in the presence of 0-1.5 % (w/v) NaCl. Phylogenetic analysis, based on 16S rRNA gene sequencing, showed that strain THG-AG6.4^T was most closely related to Flavobacterium gyeonganense HME 7524^T (97.66 %), Flavobacterium defluvii EMB 117^T (96.93 %) and Flavobacterium arsenitoxidans S2-3H^T (96.80 %). The DNA G+C content of strain THG-AG6.4^T was 30.2 mol%. The DNA-DNA relatedness values between strain THG-AG6.4^T and its closest phylogenetic neighbour, F. gyeonganense HME 7524^T, were below 61.0 %. The predominant quinone of strain THG-AG6.4^T was MK-6. The major polar lipids were phosphatidylethanolamine, an unidentified phospholipid, five unidentified glycolipids, phosphatidylserine, an unidentified lipid, an unidentified aminophospholipid, two unidentified aminolipids and two unidentified aminoglycolipids. The major fatty acids were C16 : 0, C18 : 0 10-methyl, summed feature 3 and C18 : 1ω9c. The major polyamine was homospermidine. On the basis of the phenotypic, genotypic and phylogenetic characterization of strain THG-AG6.4^T, it is concluded that the isolate represents a novel species of the genus Flavobacterium, for which the name Flavobacterium limi sp. nov. is proposed, with THG-AG6.4^T as the type strain (=KACC 18851^T=CGMCC 1.16060^T).

Daejeonia ginsenosidivorans gen. nov., sp. nov., a ginsenoside-transforming bacterium isolated from lake water

A Gram-stain-negative, oxidase- and catalase-positive, strictly aerobic, non-gliding bacterial strain, designated as NPT, was isolated from lake water and subjected to a taxonomic study using a polyphasic approach. Colonies of strain NP5T were light-yellow-coloured, circular with regular margins, and opaque. Cells were rods, 0.2-0.5 µm wide and 1.2-3.0 µm long. Strain NP5T possessed β-glycosidase activity, which was responsible for its ability to convert ginsenosides Rb1, Rc and Rd (three main active components of ginseng) to ginsenoside F2. Phylogenetic study based on the 16S rRNA gene sequence put strain NP5T in a distinct lineage in the family Flavobacteriaceae, sharing less than 96.0 % sequence similarity with members of the closely related genera Chryseobacterium, Bergeyella, Epilithonimonas and 'Candidatus Amoebinatus'. The novel isolate showed the highest sequence similarity with the genus Chryseobacterium. Strain NP5T contained MK-6 as predominant quinone, and iso-C15 : 0, iso-C17 : 0 3-OH, iso-C16 : 0 3-OH, C18 : 0 3-OH, anteiso-C15 : 0 and C16 : 1ω7c and/or C16 : 1ω6c (summed feature 3) as major fatty acids. The DNA G+C content was 44.8 mol%. The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The physiological, biochemical and taxonomical characteristics allowed the phenotypic differentiation of strain NP5T from its closest phylogenetic neighbours. On the basis of the evidence of this polyphasic study, isolate NP5T represents a novel genus and species in the family Flavobacteriaceae for which the name Daejeonia ginsenosidivorans gen. nov., sp. nov. is proposed. The type strain is NP5T (=KACC 18626T=LMG 29198T).

Taxonogenomics and description of Vaginella massiliensis gen. nov., sp. nov., strain Marseille P2517T, a new bacterial genus isolated from the human vagina

An obligate aerobic, Gram-negative, nonmotile and nonsporulating rod designated Marseille P2517 was isolated from the vaginal flora. We describe its features, annotate the genome and compare it to the closest species. The 16S rRNA analysis shows 93.03% sequence similarity with Weeksella virosa, the phylogenetically closest species. Its genome is 2 434 475 bp long and presents 38.16% G+C. On the basis of these data, it can be considered as a new genus in the Flavobacteriaceae family, for which we proposed the name Vaginella massiliensis gen. nov., sp. nov. The type strain is Marseille P2517T.

Genome-Based Taxonomic Classification of Bacteroidetes

The bacterial phylum Bacteroidetes, characterized by a distinct gliding motility, occurs in a broad variety of ecosystems, habitats, life styles, and physiologies. Accordingly, taxonomic classification of the phylum, based on a limited number of features, proved difficult and controversial in the past, for example, when decisions were based on unresolved phylogenetic trees of the 16S rRNA gene sequence. Here we use a large collection of type-strain genomes from Bacteroidetes and closely related phyla for assessing their taxonomy based on the principles of phylogenetic classification and trees inferred from genome-scale data. No significant conflict between 16S rRNA gene and whole-genome phylogenetic analysis is found, whereas many but not all of the involved taxa are supported as monophyletic groups, particularly in the genome-scale trees. Phenotypic and phylogenomic features support the separation of Balneolaceae as new phylum Balneolaeota from Rhodothermaeota and of Saprospiraceae as new class Saprospiria from Chitinophagia. Epilithonimonas is nested within the older genus Chryseobacterium and without significant phenotypic differences; thus merging the two genera is proposed. Similarly, Vitellibacter is proposed to be included in Aequorivita. Flexibacter is confirmed as being heterogeneous and dissected, yielding six distinct genera. Hallella seregens is a later heterotypic synonym of Prevotella dentalis. Compared to values directly calculated from genome sequences, the G+C content mentioned in many species descriptions is too imprecise; moreover, corrected G+C content values have a significantly better fit to the phylogeny. Corresponding emendations of species descriptions are provided where necessary. Whereas most observed conflict with the current classification of Bacteroidetes is already visible in 16S rRNA gene trees, as expected whole-genome phylogenies are much better resolved.

Description of Sphingomonas mohensis sp. nov., Isolated from Sediment

An aerobic, gram-reaction-negative, rod-shaped bacterium, designated strain Z6(T), was isolated from sediment collected at Mohe Basin, China. And its taxonomic position was investigated by applying a polyphasic approach. Growth occurs at 10-45 °C (optimum, 30 °C), at pH 6.0-11.0 (optimum, pH 7.0) and in the presence of 0-3.0 % (w/v) NaCl (optimum, 0 %). The polar lipid profile of strain Z6(T) revealed the presence of diphosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and two unidentified phospholipids, and the major quinone was Q-10. The major fatty acids were C18:1 ω7c and/or C18:1 ω6c (summed feature 8) and C16:1 ω6c and/or C16:1 ω7c (summed feature 3). The predominant polyamine was homospermidine. The DNA G + C content of strain Z6(T) is 65.2 mol%. On the basis of the polyphasic evidence presented, strain Z6(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas mohensis sp. nov. is proposed. The type strain is Z6(T) (=CGMCC 1.12891(T) = JCM 19983(T)).

Qipengyuania sediminis gen. nov., sp. nov., a member of the family Erythrobacteraceae isolated from subterrestrial sediment

A Gram-reaction-negative, non-motile, facultatively aerobic bacterium, designated strain M1T, was isolated from a subterrestrial sediment sample of Qiangtang Basin in Qinghai-Tibetan plateau, China. The strain formed rough yellow colonies on R2A plates. Cells were oval or short rod-shaped, catalase-positive and oxidase-negative. Phylogenetic analyses based on 16S rRNA gene sequences indicated that the isolate belonged to the family Erythrobacteraceae and showed 96.2–96.4 % 16S rRNA gene sequence similarities to its closest relatives. Chemotaxonomic analysis revealed ubiquinone-10 (Q10) as the dominant respiratory quinone of strain M1T and C17 : 1ω6c (44.2 %) and C18 : 1ω7c (13.7 %) as the major fatty acids. The major polar lipids were phosphatidylethanolamine, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, sphingoglycolipid, three unidentified glycolipids, one unidentified phosphoglycolipid and one unidentified lipid. The DNA G+C content of strain M1T was 73.7 mol%. On the basis of phenotypic, phylogenetic and genotypic data presented in this study, strain M1T represents a novel species of a new genus in the family Erythrobacteraceae, for which the name Qipengyuania sediminis gen. nov., sp. nov. is proposed. The type strain of the type species is M1T ( = CGMCC 1.12928T = JCM 30182T).

Empedobacter stercoris sp. nov., isolated from an input sample of a biogas plant

Two Gram-stain-negative, rod-shaped bacteria, strains 990B6_12ER2AT and 994B6_12ER2A, were isolated during microbiological analysis of a mixed manure sample which was used as input material for a German biogas plant. Phylogenetic identification based on nearly full-length 16S rRNA gene sequences placed the isolates into the family Flavobacteriaceae within the phylum Bacteroidetes. Strains 990B6_12ER2AT and 994B6_12ER2A shared identical 16S rRNA gene sequences and showed highest 16S rRNA gene sequence similarity to the type strains of Empedobacter falsenii (97.3 %) and Empedobacter brevis (96.8 %).The major cellular fatty acids of strains 990B6_12ER2AT and 994B6_12ER2A were iso-C15 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and iso-C17 : 0 3-OH.The polyamine pattern contained predominantly sym-homospermidine and the quinone system was menaquinone MK-6. Major polar lipids were phosphatidylethanolamine, one unidentified aminolipid and one unidentified polar lipid not containing an amino residue, a phosphate residue or a sugar moiety. In addition, moderate to minor amounts of several unidentified lipids were detected. The DNA G+C content was 31.7 and 29.0 mol%, for strains 990B6_12ER2AT and 994B6_12ER2A, respectively. On the basis of phylogenetic, chemotaxonomic and physiological analysis we propose a novel species of the genus Empedobacter, Empedobacter stercoris sp. nov. (type strain 990B6_12ER2AT = CIP 110833T = LMG 28501T).

Altererythrobacter buctense sp. nov., isolated from mudstone core

A yellow-pigmented, Gram-negative, non-flagellated, rod-shaped bacterial strain, designated M0322(T), was isolated from a mudstone core sample of the Mohe Basin, China. Growth of strain M0322(T) was observed at 15-40 °C (optimum, 30 °C), at pH 5.0-10.0, (optimum, pH 6.0-7.0) and in the presence 0-4 % NaCl (optimum, 0 %). Phylogenetic analyses of 16S rRNA gene sequences revealed that strain M0322(T) formed a distinct phyletic lineage with the members of the genus Altererythrobacter and is closely related to Altererythrobacter aestuarii JCM 16339(T) (96.1 %) and Altererythrobacter namhicola JCM 16345(T) (95.7 %). The only isoprenoid quinone was identified as ubiquinone 10 (Q-10), major polar lipids were determined to be phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine, one unidentified glycolipid and three unidentified phospholipids, while major cellular fatty acids were summed feature 8 (C18:1 ω6c and/or C18:1 ω7c), summed feature 3 (C16:1 ω6c and/or C16:1 ω7c) and 11-Methyl C18:1 ω7c. The DNA G+C content of strain M0322(T) was determined to be 64.6 mol%. Based on the results of the polyphasic taxonomic study, strain M0322(T) is considered to represent a novel species of the genus Altererythrobacter, for which the name Altererythrobacter buctense sp. nov. is proposed. The type strain is M0322(T) (=CGMCC 1.12871(T) = JCM 30112(T)).

Apibacter adventoris gen. nov., sp. nov., a member of the phylum Bacteroidetes isolated from honey bees

Honey bees and bumble bees harbour a small, defined set of gut bacterial associates. Strains matching sequences from 16S rRNA gene surveys of bee gut microbiotas were isolated from two honey bee species from East Asia. These isolates were mesophlic, non-pigmented, catalase-positive and oxidase-negative. The major fatty acids were iso-C15 : 0, iso-C17 : 0 3-OH, C16 : 0 and C16 : 0 3-OH. The DNA G+C content was 29-31 mol%. They had ∼87 % 16S rRNA gene sequence identity to the closest relatives described. Phylogenetic reconstruction using 20 protein-coding genes showed that these bee-derived strains formed a highly supported monophyletic clade, sister to the clade containing species of the genera Chryseobacterium and Elizabethkingia within the family Flavobacteriaceae of the phylum Bacteroidetes. On the basis of phenotypic and genotypic characteristics, we propose placing these strains in a novel genus and species: Apibacter adventoris gen. nov., sp. nov. The type strain of Apibacter adventoris is wkB301T ( = NRRL B-65307T = NCIMB 14986T).

Noncontiguous finished genome sequence and description of Weeksella massiliensis sp. nov

Strain FF8(T) (= CSUR P860 = DSM 28259) was isolated in Dakar, Senegal, from the urine of a 65-year-old man with acute cystitis. This strain shows a similarity of sequence of 16S rRNA of 98.38% with Weeksella virosa, and its GenBank accession numbers are HG931340 and CCMH00000000. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry analysis had a poor score, ranging from 1.32 to 1.56, that did not allow identification of the bacterium. Using a polyphasic study made of phenotypic and genomic analyses, strain FF8(T) was a Gram-negative, aerobic rod and a member of the family Flavobacteriaceae. The sequenced genome is 2 562 781 bp with one chromosome but no plasmid. It exhibits a G + C content of 35.9% and contains 2390 protein-coding and 56 RNA genes, including a complete rRNA operon. On the basis of these data, we propose the creation of Weeksella massiliensis sp. nov.

Sphingomonas arantia sp. nov., isolated from Hoh Xil basin, China

A Gram-negative, rod-shaped, non-motile, non-spore forming, aerobic, orange-pigmented bacterium, designated strain 6P(T), was isolated from a soil sample collected from the Hoh Xil basin, China. Strain 6P(T) grew optimally at 25 °C, pH 7.0-7.5 and NaCl concentration of 0-1 % (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 6P(T) belongs to the genus Sphingomonas, with high sequence similarity (97.1 %) to Sphingomonas fennica. The DNA-DNA hybridization homology with S. fennica DSM 13665(T) was 45.3 %. The DNA G+C content of the novel strain is 65.3 mol%. The isolate contained Q-10 as the only respiratory quinone. The major polar lipids are diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC) and sphingoglycolipid (SGL). C18:1 ω7c and C16:1 ω7c are the major fatty acids. On the basis of the polyphasic evidence presented, strain 6P(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas arantia sp. nov. is proposed. The type strain is 6P(T) (=CGMCC 1.12702(T) = JCM 19855(T)).

Polymorphobacter fuscus sp. nov., isolated from permafrost soil, and emended description of the genus Polymorphobacter

Strain D40P^T, representing a novel Gram-stain-negative, obligately aerobic, bacteriochlorophyll a-containing bacterium of the α-4 subgroup of the phylum Proteobacteria, was isolated from permafrost soil of Kunlun mountains gap, Qinghai-Tibet plateau. Cells were non-motile rod-cocci and formed brown-pigmented colonies. According to the absorption spectrum, carotenoids and two different photosynthetic light-harvesting complexes, an LHI complex and a B800-835-type peripheral LHII complex, were present in the cells. The strain was oxidase-negative and catalase-positive. The predominant fatty acids of strain D40P^T were summed feature 3 (C_16 : 1ω7c and/or C_16 : 1ω6c), C_17 : 1ω6c and summed feature 8 (C_18 : 1ω7c and/or C_18 : 1ω6c). The main polar lipids were phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipid, two glycolipids and sphingoglycolipid. The major respiratory quinone was ubiquinone-10, whereas ubiquinone-9 was present in smaller amounts. The 16S rRNA gene sequence similarity to the closest phylogenetic relative, Polymorphobacter multimanifer JCM 18140^T, was 97.5 %. DNA-DNA relatedness (ΔT_m) between strain D40P^T and P. multimanifer was 12.4 °C. The G+C content of the genomic DNA of strain D40P^T was 67.4 mol%. Accordingly, the strain represents a novel species, for which the name Polymorphobacter fuscus sp. nov. is proposed. The type strain is D40P^T ( = CGMCC 1.12714^T = JCM 19740^T). An emended description of the genus Polymorphobacter is also proposed.

Youhaiella tibetensis gen. nov., sp. nov., isolated from subsurface sediment

A Gram-reaction-negative bacterial strain, designated fig4T, was isolated from a subsurface sediment core of Qiangtang Basin permafrost in China. Cells were catalase- and oxidase-positive and rods. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain fig4T was a member of the family Hyphomicrobiaceae and was most closely related to members of the genera Pelagibacterium, Vasilyevaea and Devosia with 93.8–96.2 % sequence similarities. The major cellular fatty acids were C16 : 0, C18 : 0, 11-methyl C18 : 1ω7c, C19 : 0 cyclo ω8c and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The major respiratory quinone was Q-10 and the major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. The DNA G+C content was 60.7 mol%. Based on the phenotypic, phylogenetic and genotypic data, strain fig4T is considered to represent a novel species of a new genus in the family Hyphomicrobiaceae, for which the name Youhaiella tibetensis gen. nov., sp. nov. is proposed. The type strain is fig4T ( = CGMCC 1.12719T = JCM 19854T).

The microbial diversity, distribution, and ecology of permafrost in China: a review

Permafrost in China mainly located in high-altitude areas. It represents a unique and suitable ecological niche that can be colonized by abundant microbes. Permafrost microbial community varies across geographically separated locations in China, and some lineages are novel and possible endemic. Besides, Chinese permafrost is a reservoir of functional microbial groups involved in key biogeochemical cycling processes. In future, more work is necessary to determine if these phylogenetic groups detected by DNA-based methods are part of the viable microbial community, and their functional roles and how they potentially respond to climate change. This review summaries recent studies describing microbial biodiversity found in permafrost and associated environments in China, and provides a framework for better understanding the microbial ecology of permafrost.

Dyadobacter sediminis sp. nov., isolated from a subterranean sediment sample

A Gram-reaction-negative, flexirubin-type-pigmented, rod-shaped, aerobic, non-motile bacterium, designated strain Z12T, was isolated from a subsurface sediment sample. In a phylogenetic tree based on 16S rRNA gene sequences, strain Z12T formed a distinct clade with the members of the genus Dyadobacter (<96.7 % sequence similarity). The G+C content of genomic DNA was 45.4 %. The major fatty acids of strain Z12T were iso-C15 : 0, C16 : 1ω6c and/or C16 : 1ω7c (summed feature 3) and anteiso-C17 : 1 B and/or iso-C17 : 1 I (summed feature 4). The major respiratory quinone was MK-7 and the major polar lipid was phosphatidylethanolamine. On the basis of phenotypic, phylogenetic and genotypic features, strain Z12T is considered to represent a novel species, for which the name Dyadobacter sediminis sp. nov., is proposed. The type strain is Z12T ( = JCM 30073T = CGMCC 1.12895T).

Flavobacterium maotaiense sp. nov., isolated from freshwater

Two novel strains, T9T and T10, were isolated from water samples collected from Chishui River flowing through Maotai town, Guizhou, south-west China. The isolates were yellow-pigmented, Gram-reaction-negative, rod-shaped, non-motile and aerobic. Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates belonged to the genus Flavobacterium , and showed highest similarities to Flavobacterium hibernum DSM 12611T (97.0 %), followed by Flavobacterium granuli Kw05T (96.7 %) and Flavobacterium pectinovorum DSM 6368T (96.7 %). The novel strains were able to grow at 20–37 °C (optimum 25 °C), pH 7.0–10.0 (optimum pH 7.0–8.0) and with 0–0.5 % (w/v) NaCl (optimum 0.5 %). The predominant fatty acids were iso-C15 : 0, C16 : 1ω7c, anteiso-C15 : 0, C15 : 0, iso-C15 : 0 3-OH and iso-C15 : 1ω10c, and menaquinone-6 (MK-6) was the main respiratory quinone. The major polar lipids were phosphatidylethanolamine, one unknown glycolipid, two unknown aminolipids and two unidentified lipids. The DNA G+C contents of strains T9T and T10 were 37.7 and 36.4 mol%, respectively. According to the phenotypic and genetic data, strains T9T and T10 represent a novel species in the genus Flavobacterium , for which the name Flavobacterium maotaiense sp. nov. is proposed. The type strain is T9T ( = CGMCC 1.12712T = JCM 19927T).

Arenimonas maotaiensis sp. nov., isolated from fresh water

A translucent, white, Gram-reaction-negative, facultatively anaerobic, non-flagellated, slightly curved or curved bacterial strain, designated YT8(T), was isolated from the fresh water of the Maotai section of Chishui River, China. Cells were catalase-positive and oxidase-positive. Phylogenetic analyses of 16S rRNA gene sequences revealed that strain YT8(T) is a member of the genus Arenimonas with similarity to other members of this genus ranging from 93.7 to 95.0 %. The major isoprenoid quinone was ubiquinone 8 (Q-8), major polar lipids were phosphatidylethanolamine, one unidentified aminolipid, two unidentified phospholipids and two unidentified polar lipids, while major fatty acids were iso-C15 : 0, iso-C14 : 0 and anteiso-C15 : 0. The DNA G+C content of strain YT8(T) was 66.6 mol%. On the basis of phenotypic, phylogenetic and genotypic features studied, strain YT8(T) is suggested to represent a novel species of the genus Arenimonas, for which the name Arenimonas maotaiensis sp. nov. is proposed. The type strain is YT8(T) ( = CGMCC 1.12726(T) = JCM 19710(T)).

Description of Chishuiella changwenlii gen. nov., sp. nov., isolated from freshwater, and transfer of Wautersiella falsenii to the genus Empedobacter as Empedobacter falsenii comb. nov

A Gram-reaction-negative, strictly aerobic, non-pigmented, non-gliding, rod-shaped bacterium, designated strain BY4(T), was isolated from freshwater. Cells were catalase- and oxidase-positive and indole was produced. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain BY4(T) belonged to the family Flavobacteriaceae and showed 91.6-95.9% sequence similarities to the most closely related strains. The major respiratory quinone was MK-6 and the major polar lipid was phosphatidylethanolamine. The major polyamine was homospermidine and the major fatty acids were iso-C(15 : 0), iso-C(17 : 0) 3-OH and summed feature 3 (C(16 : 1)ω7c and/or C(16 : 1)ω6c). The DNA G+C content was 30.0 mol%. On the basis of phenotypic, phylogenetic and genotypic features, strain BY4(T) is suggested to represent a novel species in a new genus within the family Flavobacteriaceae, for which the name Chishuiella changwenlii gen. nov., sp. nov. is proposed. The type strain of this type species is BY4(T) ( = CGMCC 1.12707(T) = JCM 19633(T)). On the basis of data collected from previous and present studies, it is proposed to reclassify Wautersiella falsenii to the genus Empedobacter as the new combination Empedobacter falsenii comb. nov. (type strain NF 993(T) = CCUG 51536(T) = CIP 108861(T)).