Family Chitinophagaceae Research Articles

Polluticaenibacter yanchengensis gen. nov., sp. nov., A Novel Taxon Within the Family Chitinophagaceae Isolated from Activated Sludge.

A Gram-stain-negative bacterium, designated strain LY-5T, was isolated from an activated sludge sample collected from a river in Yancheng city, Jiangsu province, China. Cells of strain LY-5T, were strictly aerobic, non-motile and rod-shaped. Growth occurred at 15-37°C (optimum, 30°C), at pH 5.0-9.0 (optimum 7.0) and at 0-3% (w/v) NaCl (optimum, 0%). Phylogenetic analysis based on 16S rRNA gene and genome sequences indicated that strain LY-5T formed a distinct phyletic branch within the family Chitinophagaceae, with closest relatives being members of the genera Phnomibacter, Aurantisolimonas, and Chitinophaga, sharing 88.5-90.3% sequence similarity. Moreover, the average amino acid identity (AAI) between strain LY-5T and its closed phylogenetic neighbors was below 70%, indicating it belongs to a novel genus. The predominant cellular fatty acids of LY-5T were iso-C15:0, iso-C15:1 G and summed feature 3 (C16:1 ω7c and/or C16:1 ω6c), and the only isoprenoid quinone was menaquinone-7 (MK-7). The major polar lipids identified in strain LY-5T comprised phosphatidylethanolamine, two unidentified aminolipids and five unidentified lipids. The genome size of strain LY-5T was 4.8 Mbp with a G + C content of 38.9%. Based on the evidence presented in this study, strain LY-5T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Polluticaenibacter yanchengensis gen. nov., sp. nov. (Type strain LY-5T = CCTCC AB 2023260T = KCTC 102218T) is proposed.

Niabella digestorum sp. nov., a High Cell-Surface Hydrophobic Bacterium Isolated from Waste Digestion System.

A high cell-surface hydrophobic bacterium, strain A18T, was isolated from a waste digestion system in Chaozhou, China. Cells of strain A18T were Gram-stain-positive, aerobic, non-spore-forming, non-motile, and rod-shaped. Phylogenetic analyses based on the 16S rRNA gene showed that strain A18T shared less than 94.2% sequence similarity to all validated species in the family Chitinophagaceae, and formed a distinct lineage close to genera Niabella and Terrimonas in the neighbor-joining tree, indicating that strain A18T is a novel species. Genome-based phylogenetic analyses revealed that strain A18T is affiliated to the genus Niabella. The cellular components, including iso-C15:0 and iso-C15:1 G as the major fatty acids, menaquinone-7 as the respiratory quinone and a DNA G + C content of 40.54% supported strain A18T as a member of the genus Niabella. However, the physiological and biochemical properties, such as enzyme activities, carbon source utilization and C18:0 3-OH as another major fatty acids, distinguished strain A18T from its close related species. Therefore, the name Niabella digestorum sp. nov. is proposed for this novel species. The type strain is A18T (= GDMCC 1.3242T = KCTC 92386T).

Mycovorax composti gen. nov., sp. nov., a member of the family Chitinophagaceae isolated from button mushroom compost.

Two Gram-stain-negative, aerobic, rod-shaped, orange-coloured bacterial strains, designated strain C216T and strain M2295, were isolated from mature mushroom compost from composting facilities in Victoria and South Australia, Australia, respectively. External structures such as flagella or pili were not observed on the cells under scanning electron microscopy. Optimal growth was found to occur at 45 °C, at pH 7.25 and in the absence of NaCl on Emerson's 350 YpSs medium. The genome sequence of strain C216T was 3 342 126 bp long with a G+C content of 40.5 mol%. Functional analysis of the genome of strain C216T revealed genes encoding chitinolytic and hemi-cellulolytic functions, with 166 predicted genes associated with carbohydrate metabolism (8.9% of the predicted genes). These functions are important for survival in the mushroom compost environment, which is rich in hemicelluloses. No antibiotic resistance genes were found in the genome sequence. The major fatty acids of strain C216T were iso-C15 : 0 (56.7%), iso-C17 : 0 3-OH (15.6%), C16 : 1 ω7c/iso-C15 : 0 2-OH (7.3%) and iso-C15 : 1 G (6.1%). The only respiratory quinone was MK-7. The major polar lipid of strain C216T was phosphatidylethanolamine, but three unidentified phospholipids, four unidentified aminophospholipids/aminolipids and one unidentified glycolipid were also detected. Phylogenetic analysis based on proteins encoded by the core genome (bac120, 120 conserved bacterial genes) showed that strain C216T forms a distinct lineage in the family Chitinophagaceae and that the closest identified relative is Niabella soli (69.69% ANI). These data demonstrate that strain C216T represents a novel genus and novel species within the family Chitinophagaceae, for which we propose the name Mycovorax composti. The type strain is C216T (=DSM 114558T=LMG 32998T).

Environmental factors and host sex influence the skin microbiota structure of Hong Kong newt (Paramesotriton hongkongensis) in a coldspot of chytridiomycosis in subtropical East Asia.

Chytridiomycosis, an infectious skin disease caused by the chytrid fungi, Batrachochytrium dendrobatidis and B. salamandrivorans, poses a significant threat to amphibian biodiversity worldwide. Antifungal bacteria found on the skin of chytrid-resistant amphibians could potentially provide defense against chytridiomycosis and lower mortality rates among resistant individuals. The Hong Kong newt (Paramesotriton hongkongensis) is native to East Asia, a region suspected to be the origin of chytrids, and has exhibited asymptomatic infection, suggesting a long-term coexistence with the chytrids. Therefore, the skin microbiota of this resistant species warrant investigation, along with other factors that can affect the microbiota. Among the 149 newts sampled in their natural habitats in Hong Kong, China, putative antifungal bacteria were found in all individuals. There were 314 amplicon sequence variants distributed over 25 genera of putative antifungal bacteria; abundant ones included Acinetobacter, Flavobacterium, and Novosphingobium spp. The skin microbiota compositions were strongly influenced by the inter-site geographical distances. Despite inter-site differences, we identified some core skin microbes across sites that could be vital to P. hongkongensis. The dominant cores included the family Comamonadaceae, family Chitinophagaceae, and class Betaproteobacteria. Moreover, habitat elevation and host sex also exhibited significant effects on skin microbiota compositions. The antifungal bacteria found on these newts offer an important resource for conservation against chytridiomycosis, such as developing probiotic treatments for susceptible species.

Paraflavitalea pollutisoli sp. nov., Pollutibacter soli gen. nov. sp. nov., Polluticoccus soli gen. nov. sp. nov., and Terrimonas pollutisoli sp. nov., four new members of the family Chitinophagaceae from polluted soil

A taxonomic investigation was conducted on four bacterial strains isolated from soil contaminated with polycyclic aromatic hydrocarbons and heavy metals. Phylogenetic analysis revealed that these strains belonged to the family Chitinophagaceae. Examination of the 16S rRNA genes indicated that their sequence identities were below 97.6 % compared to any known and validly nominated bacterial species. The genomes of the four strains ranged from 4.12 to 8.76 Mb, with overall G + C molar contents varying from 41.28 % to 50.39 %. Predominant cellular fatty acids included iso-C15:0, iso-C15:1 G, and iso-C17:0 3-OH. The average nucleotide identity ranged from 66.90 % to 74.63 %, and digital DNA-DNA hybridization was 12.5–12.8 %. Based on the genomic and phenotypic features of the new strains, four novel species and two new genera were proposed within the family Chitinophagaceae. The ecological distributions were investigated by data-mining of NCBI databases, and results showed that additional strains or species of the newly proposed taxa were widely distributed in various environments, including polluted soil and waters. Functional analysis demonstrated that strains H1-2-19XT, JS81T, and JY13-12T exhibited resistance to arsenite (III) and chromate (VI). The proposed names for the four novel species are Paraflavitalea pollutisoli (type strain H1-2-19XT = JCM 36460T = CGMCC 1.61321T), Terrimonas pollutisoli (type strain H1YJ31T = JCM 36215T = CGMCC 1.61343T), Pollutibacter soli (type strain JS81T = JCM 36462T = CGMCC 1.61338T), and Polluticoccus soli (type strain JY13-12T = JCM 36463T = CGMCC 1.61341T).

A novel plant growth-promoting rhizobacterium, Rhizosphaericola mali gen. nov., sp. nov., isolated from healthy apple tree soil

The rhizosphere microbial community is closely associated with plant disease by regulating plant growth, agricultural production, nutrient availability, plant hormone and adaptation to environmental changes. Therefore, it is very important to identify the rhizosphere microbes around plant roots and understand their functions. While studying the differences between the rhizosphere microbiota of healthy and diseased apple trees to find the cause of apple tree disease, we isolated a novel strain, designated as B3-10T, from the rhizosphere soil of a healthy apple tree. The genome relatedness indices between strain B3-10T and other type species of family Chitinophagaceae were in the ranges of 62.4–67.0% for ANI, 18.6–32.1% for dDDH, and 39.0–56.6% for AAI, which were significantly below the cut‑off values for the species delineation, indicating that strain B3-10T could be considered to represent a novel genus in family Chitinophagaceae. Interestingly, the complete genome of strain B3-10T contained a number of genes encoding ACC-deaminase, siderophore production, and acetoin production contributing to plant-beneficial functions. Furthermore, strain B3-10T was found to significantly promote the growth of shoots and roots of the Nicotiana benthamiana, which is widely used as a good model for plant biology, demonstrating that strain B3-10T, a rhizosphere microbe of healthy apple trees, has the potential to promote growth and reduce disease. The phenotypic, chemotaxonomic, phylogenetic, genomic, and physiological properties of this plant growth-promoting (rhizo)bacterium, strain B3-10T supported the proposal of a novel genus in the family Chitinophagaceae, for which the name Rhizosphaericola mali gen. nov., sp. nov. (= KCTC 72123T = NBRC 114178T).

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

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

Differences in Microbial Community Composition between Uterine Horns Ipsilateral and Contralateral to the Corpus Luteum in Beef Cows on Day 15 of the Estrous Cycle.

This study evaluated differences in uterine microbiota composition between uterine horns ipsilateral and contralateral to the corpus luteum of beef cows on day 15 of the estrous cycle. Cows (n = 23) were exposed to an estrus synchronization protocol to exogenously induce synchronized ovulation. Cows were then euthanized on day 15 of the estrous cycle, and individual swabs were collected from uterine horns ipsilateral and contralateral to the corpus luteum using aseptic techniques. DNA was extracted, and the entire (V1-V9 hypervariable regions) 16s rRNA gene was sequenced. Sequences were analyzed, and amplicon sequence variants (ASVs) were determined. Across all samples, 2 bacterial domains, 24 phyla, and 265 genera were identified. Butyribirio, Cutibacterium, BD7-11, Bacteroidales BS11 gut group, Ruminococcus, Bacteroidales RF16 group, and Clostridia UCG-014 differed in relative abundances between uterine horns. Rikenellaceae RC9 gut group, Bacteroidales UCG-001, Lachnospiraceae AC2044 group, Burkholderia-Caballeronia-Paraburkholderia, Psudobutyribibrio, and an unidentified genus of the family Chitinophagaceae and dgA-11 gut group differed between cows that expressed estrus and those that did not. The composition of the microbial community differed between the ipsilateral and contralateral horns and between cows that expressed estrus and cows that failed to express estrus, indicating that the uterine microbiota might play a role in cow fertility.

Isolation and characterization of a novel glycoside hydrolase positive bacterial strain named Terrimonas ginsenosidimutans sp. nov. with ginsenoside-converting activity.

A novel yellow-pigmented catalase- and oxidase-positive bacterial strain (designated NA20T) was isolated from wetland soil and characterized. Results of 16S rRNA and draft genome sequence analysis placed strain NA20T within the genus Terrimonas of the family Chitinophagaceae. Strain NA20T showed ≤97.1 % sequence similarity to members of the genus Terrimonas and the highest sequence similarity was found to Terrimonas lutea DYT (97.1%). The draft genome of strain NA20T had a total length of 7 144 125 base pairs. A total of 5659 genes were identified, of which 5613 were CDS and 46 RNA genes were assigned a putative function. Mining the genomes revealed the presence of 225 carbohydrate genes out of 1334 genes. Strain NA20T contained iso-C15 : 0, iso-C15 : 0 G, iso-C17 : 0 3-OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) as major fatty acids. The predominant quinone was MK-7. The major polar lipids were phosphatidylethanolamine, one unknown polar lipid and one unknown aminophospholipid. Additionally, the functional analysis of NA20T showed the conversion of protopanaxatriol-mix type major ginsenosides (Rb1, Rc and Rd) to minor ginsenosides F2 and weak conversion of Rh2 and C-K within 24 h. As a result, the genotypic, phenotypic and taxonomic analyses support the affiliation of NA20T within the genus Terrimonas, for which the name Terrimonas ginsenosidimutans sp. nov. is proposed. The type strain is NA20T (=KACC 22218T=LMG 32198T).

Does wood mulch trigger microbially mediated positive plant-soil feedback in degraded boreal forest sites? A post hoc study.

Reforestation of degraded lands in the boreal forest is challenging and depends on the direction and strength of the plant-soil feedback (PSF). Using a gradient in tree productivity (null, low and high) from a long-term, spatially replicated reforestation experiment of borrow pits in the boreal forest, we investigated the interplay between microbial communities and soil and tree nutrient stocks and concentrations in relation to a positive PSF induced by wood mulch amendment. Three levels of mulch amendment underlie the observed gradient in tree productivity, and plots that had been amended with a continuous layer of mulch 17 years earlier showed a positive PSF with trees up to 6 m tall, a closed canopy, and a developing humus layer. The average taxonomic and functional composition of the bacterial and fungal communities differed markedly betweenlow- and high-productivity plots. Trees in high-productivity plots recruited a specialized soil microbiome that was more efficient at nutrient mobilization and acquisition. These plots showed increases in carbon (C), calcium (Ca), nitrogen (N), potassium (K), and phosphorus (P) stocks and as well as bacterial and fungal biomass. The soil microbiome was dominated by taxa from the fungal genus Cortinarius and the bacterial family Chitinophagaceae, and a complex microbial network with higher connectivity and more keystone species supported tree productivity in reforested plots compared to unproductive plots. Therefore, mulching of plots resulted in a microbially mediated PSF that enhances mineral weathering and non-symbiotic N fixation, and in turn helps transform unproductive plots into productive plots to ensure rapid restoration of the forest ecosystem in a harsh boreal environment.

Paraflavisolibacter caeni gen. nov., sp. nov., a novel taxon within the family Chitinophagaceae isolated from sludge.

A Gram-stain-negative bacterium, designated strain LB-8T, was isolated from an activated sludge sample collected from a factory in Binzhou city, Shandong province, PR China. Cells of strain LB-8T were strictly aerobic, non-motile and rod-shaped. Growth occurred at 15-40 °C (optimum, 30 °C), at pH 6.0-9.0 (optimum, pH 7.0) and at 0-7.5 % (w/v) NaCl (optimum, 0.5 % NaCl). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain LB-8T formed a distinct phyletic branch within the family Chitinophagaceae and was most closely related to members of the genera Flavisolibacter, Cnuella and Paracnuella with 92.7-93.3 % 16S rRNA gene sequence similarities. The average amino acid identity values between strain LB-8T and its closed phylogenetic neighbours Flavisolibacter, Cnuella and Paracnuella were below 70 % supporting that strain LB-8T was a member of a novel genus. The predominant cellular fatty acids of LB-8T were iso-C15 : 0, anteiso-C15 : 0, summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and iso-C17 : 0 3-OH, and the only isoprenoid quinone was menaquinone-7 (MK-7). The major polar lipids of strain LB-8T were phosphatidylethanolamine, four unidentified aminolipids and two unidentified lipids. The genome size of strain LB-8T was 7.01 Mbp with 41.2 mol% G+C content. On the basis of the evidence presented in this study, strain LB-8T represents a novel species of a new genus in the family Chitinophagaceae, for which the name Paraflavisolibacter caeni gen. nov., sp. nov. (type strain LB-8T=GDMCC 1.3631T=KCTC 92688T) is proposed.

Soil Suppressiveness Against Pythium ultimum and Rhizoctonia solani in Two Land Management Systems and Eleven Soil Health Treatments.

The soil microbiome is known to be crucial for the control of soil-borne plant diseases. However, there is still little knowledge on how to modify the soil microbiome to induce or increase disease suppressiveness. In the present study, we applied eleven soil health treatments combined with conventional and organic agricultural management in a long-term field experiment. Suppressiveness against Pythium ultimum and Rhizoctonia solani was assessed in bioassays for 2 years. In addition, the microbiome community composition and microbial abundance were determined. We found that while several treatments changed the microbial community composition compared to the control, only a combination treatment of anaerobic soil disinfestation, hair meal, and compost addition resulted in suppressiveness against P. ultimum. Pythium suppressiveness is likely to have been caused by an increased microbial abundance and activity. Moreover, the increased abundance of several bacterial taxa, such as Pseudomonas sp., Chryseobacterium sp., members of the family Chitinophagaceae, and the fungal genus Mortierella sp. and family Trichosporonaceae, was measured. There was no overall difference in suppressiveness between conventional and organic land management. Also, no suppressiveness against R. solani could be detected. Our results indicate that a treatment combining the reduction of microorganisms followed by a recovery phase with high amounts of organic amendments may be more effective in inducing suppressiveness than treatments consisting of only one of these measures.

Evaluating the Optimal Oil Concentrations in the Startup Performance of a Membrane Bioreactor Treating Oily Noodle-soup Wastewater

The discharge of high-strength oily wastewater adversely affects the environment; therefore, the treatment of wastewater containing fats, oils, and grease from the food industry is of importance. In this study, we used a membrane bioreactor (MBR) to treat Ramen noodle-soup wastewater, and we evaluated the optimal oil concentration in the wastewater for the startup of the MBR treatment in winter and summer. The MBR system had a sufficient startup in both seasons when fed with a 20-fold dilution of the original oily wastewater, containing approximately 950 to 1,200 mg/L oil and approximately 3,000 to 4,400 mg/L biological oxygen demand (BOD; BOD-SS load of 0.1 to 0.2 kg/kg/d). The reactor performance in winter were relatively stable during the operation. While, activated sludge microbes in summer were not highly active with a 40-fold dilution of wastewater, because of the decreased mixed liquor suspended solid concentration during the operation period. Population shifts in the sludge microbiome with increasing oil concentrations were analyzed using high-throughput sequencing, and the relative abundance of operational taxonomic units belonging to the phylum Bacteroidetes were highest in both winter and summer when fed with 20-fold dilution of the wastewater. In particular, the family Chitinophagaceae was dominant, with relative abundances of 13.5% in winter and 5.1% in summer, suggesting that this family may play important roles in the startup of a MBR treating the wastewater.

The core microbiome of Carya illinoinensis (pecan) seedlings of different maternal pecan cultivars from the same orchard

Carya illinoinensis (pecan) produce a high valued and desired nut crop; with production expanding worldwide. Important attributes of pecans and their ability to adapt to different environments aside from their native regions are currently being investigated. Microbial communities are known to play an important role in crop productivity and overall plant health. Studies in other plant species have shown that the plant microbiome may be influenced by both the environmental conditions and genetics of the plant. Microbiota research in pecan is in its early stages and here we report insights into the core microbiome of seedlings derived from five pecan cultivars located in an orchard from Las Cruces, New Mexico. Seeds from open-pollinated pecan cultivars (‘Burkett’, ‘Mandan’, ‘Pawnee’, ‘Western’, and ‘Wichita’) were collected and grown in a quarantine greenhouse under highly regulated conditions. DNA from the resulting seedlings were used for next generation sequencing (MiSeq) for 16S and ITS and microbiome analyses revealed significant differences in microbial composition and relative abundance (bacterial and fungal) between seedling organs, with roots having the highest alpha diversity followed by stems and leaves. Bacterial family Chitinophagaceae was identified to be most relatively abundant in the roots of seedlings compared to the bacterial families Rhizobiaceae and Moraxellaceae, which were found to be most relatively abundant in the stems and leaves, respectively. Analyses also indicated that there were several families (bacterial families: Rhizobiaceae, Enterobacteriaceae, Chitinophagaceae, Burkholderiaceae, Sphingomonadaceae, Pseudomonadaceae, Moraxellaceae, Microscillaceae, Rubritaleaceae, Caulobacteraceae; fungal families: Serendipitaceae, Nectriaceae, Ophiostomataceae, Hypocreaceae, Aspergillaceae, and Cephalothecaceae) that were found in all seedlings and these constitute a core microbiome for pecan. There were also differences in microbial composition (bacterial and fungal) between seedlings from different maternal pecan cultivars and these differences are proposed to constitute a signature microbiome for the maternal cultivar. As pecan trees continues to extend to other growing regions it is important to understand the role that these microbes play in pecan. By establishing the core microbiome of pecans, the selection of microbes for breeding and improving pecan production will become a possibility.

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

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

Hanamia caeni gen. nov., sp. nov., a Member of the Family Chitinophagaceae Isolated from Activated Sludge in Korea.

A novel Gram-stain-negative, aerobic, yellowish-pigmented, non-motile, rod-shaped bacterial strain, designated strain BO-59T, was isolated from the activated sludge of a wastewater treatment plant in Hanam City, South Korea. Phylogenetic study based on the 16S rRNA gene sequence positioned BO-59T in a distinct lineage in the family Chitinophagaceae, sharing less than 92.8% sequence similarity with members of the closely related genera Ferruginibacter, Flavitalea, Pseudoflavitalea, Flavisolibacter, Niastella, and Terrimonas. Phylogenomic- and genomic relatedness analyses revealed that strain BO-59T is clearly distinguished from other genera in the family Chitinophagaceae by average nucleotide identity < 66.9%) and the genome-to-genome distance (< 29.5%) values. The strain BO-59T contained MK-7 as the predominant quinone, and iso-C15:0, iso-C17:0 3OH, and iso-C15:1 G as major fatty acids (> 10%). The DNA G + C content was 39.1mol% based on genome sequence analysis. The polar lipids of strain BO-59T were phosphatidylethanolamine, an unidentified aminophospholipid and three unidentified polar lipids. 16S rRNA gene sequence similarity, physiological, and biochemical characteristics indicated that strain BO-59T represents a novel species of a new genus, for which the name Hanamia caeni gen. nov., sp. nov. is proposed. The type strain is BO-59T (= KACC 19646T = LMG 30865T).

Physiological and Genomic Characterization of Two Novel Bacteroidota Strains Asinibacterium spp. OR43 and OR53

Asinibacterium spp. (Family Chitinophagaceae, Phylum Bacteroidota) are abundant in environments contaminated with heavy metals. We characterized the physiology and genome of two Asinibacterium species to elucidate their ability to survive and grow at ambient conditions in the uranium-contaminated environments. Both strains were able to grow at pH 4.5 or 50 mM nitrate under aerobic conditions and did not grow with alternative electron acceptors under anaerobic conditions. Asinibacterium sp. OR53 grew in medium with uranium concentrations up to 300 µM uranium while Asinibacterium sp. OR43 could not grow at uranium concentrations &gt; 200 µM. Elemental mapping using energy dispersive X-ray spectroscopy indicate that uranium co-localized with phosphorus-containing compounds on the cell surface. Genes potentially encoding resistance mechanisms to a variety of heavy metals were detected in the genomes of both strains. The localization of uranium and missing acidic and alkaline phosphatase genes in the genome suggest that biosorption of uranium to the lipopolysaccharide layer might be the mechanism of uranium resistance. In summary, Asinibacterium spp. OR43 and OR53 are physiologically similar to closely related strains within the Chitinophagaceae family but are uniquely acclimated to the presence of uranium and other heavy metals prevalent in the subsurface at Oak Ridge, Tennessee.

Limnovirga soli gen. nov., sp. nov., isolated from river sediment.

A cream-coloured, Gram-stain-negative, rod-shaped bacterium, designated strain KSC-6T, was isolated from soil sampled at the Gapcheon River watershed in Daejeon, Republic of Korea. The organism does not require NaCl for growth and grows at pH 6.0-8.0 (optimum, pH 7.0) and 10-37 °C (optimum, 25 °C). Phylogenetic trees based on the 16S rRNA gene sequences reveal that strain KSC-6T belongs to the family Chitinophagaceae within the order Chitinophagales and is most closely related to Panacibacter ginsenosidivorans Gsoil 1550T (95.9% similarity). The genomic DNA G+C content was 38.9 mol%. The major cellular fatty acids (>8 %) of strain KCS-6T were iso-C15:0, iso-C15 : 1 G and iso-C17 : 0 3-OH. The predominant respiratory quinone was menaquinone 7 and the predominant polar lipids were phosphatidylethanolamine, five unidentified aminolipids and two unidentified lipids. Based on genome analyses, low digital DNA-DNA hybridization, average nucleotide identity and average amino acid identity values with closely related genera, and differential chemotaxonomic and physiological properties, we suggest that strain KCS-6T represents a novel species in a new genus in the family Chitinophagaceae, for which the name Limnovirga soli gen. nov., sp. nov. (type strain KCS-6T=KCCM 43337T=NBRC 114336T) is proposed.

Taibaiella lutea sp. nov., Isolated from Ubiquitous Weedy Grass.

An aerobic, Gram-stain-negative, non-motile and rod-shaped bacterial strain, designated as KVB11T was isolated from the root of plant Setaria viridis near Dongguk University. Phylogenetic analysis indicated that strain KVB11T belonged to the genus Taibaiella of the family Chitinophagaceae. Comparative 16S rRNA gene analysis indicated that the strain KVB11T has closest similarities to Taibaiella smilacinae PTJT-5T (96.6%) and Taibaiella yonginensis THG-SC4T (96.4%). Strain KVB11T grew optimally at 25-28°C, at pH 7.0 and tolerates NaCl upto 1% (w/v) NaCl. Flexirubin-type pigments were present. Phylogenetic and phylogenomic trees based on 16S rRNA gene sequences and genomic sequences demonstrated that strain KVB11T formed a distinct branch with all seven type strains of genus Taibaiella. MK-7 was identified as the predominant isoprenoid quinone. The polar lipid were phosphatidylethanolamine, one unidentified aminophosphoglycolipid, one unidentified aminoglycolipid and two unidentified phosphoglycolipids. C15:0 (28.3%), iso-C15:1 G (28.5%) and iso-C17:0 3-OH (10.5%) were the major fatty acids of the strain KVB11T. The DNA G + C content of the genomic DNA of novel isolate was determined to be 38.9%. The above results clearly confirmed that strain KVB11T represents a novel species of the genus Taibaiella, for which the name Taibaiella lutea sp. nov. is proposed. The type strain is KVB11T (= KACC 19904T = NBRC 113690T).

Flavisolibacter longurius sp. nov., isolated from soil

A novel Gram-negative bacterial strain BT320T was isolated from soil collected in Uijeongbu city, Korea. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain BT320T belong to a distinct lineage within the genus Flavisolibacter (family Chitinophagaceae, order Chitinophagales, class Chitinophagia). The strain BT320T was closely related to Flavisolibacter galbus 17J28-26T (97.6% 16S rRNA gene similarity), Flavisolibacter nicotianae X7XT (96.7%), Flavisolibacter ginsengiterrae Gsoil 492T (96.2%), and Flavisolibacter ginsengisoli Gsoil 643T (96.1%). The genome size of strain BT320T was 5,664,094bp. Bacterial growth was observed at 10-37°C (optimum 25°C) and pH 6.0-8.0 (optimum pH 7.0) on R2A agar. The major cellular fatty acids of strain BT320T were iso-C15:0, summed feature 3 (C16:1 ω6c/C16:1 ω7c), and summed feature 1 (iso-C15:1 H/C13:0 3OH). Its predominant respiratory quinone was MK-7. The major polar lipid of strain BT320T was identified to be phosphatidylethanolamine (PE). Based on the biochemical, chemotaxonomic, and phylogenetic analysis, strain BT320T can be suggested as a novel bacterial species within the genus Flavisolibacter and the proposed name is Flavisolibacter longurius. The type strain of Flavisolibacter longurius is BT320T (= KCTC 72422T = NBRC 114375T).