An aerobic, Gram-stain-negative bacterium, designated strain NIPR152T, was isolated from a glacier moss ball (glacier mice; Schistidium agassizii) collected from Ellesmere Island in the Canadian High Arctic. Cells were non-motile, rod-shaped, and formed orange-pigmented colonies. The strain grew at 4-30°C (optimum, 18°C), at pH 5.5-8.0 (optimum, pH 7.0-7.5), and tolerated up to 1.0% (w/v) NaCl. Strain NIPR152T exhibited psychrotolerant growth and hydrolyzed starch and cellulose, distinguishing it from its closest known relative. Phylogenetic analysis based on 16S rRNA gene sequences placed the strain within the genus Parasediminibacterium (family Chitinophagaceae), with the highest similarity (95.29%) to Parasediminibacterium paludis HME6815ᵀ. Genome-based analyses supported its novelty, with OrthoANIu and in silico DNA-DNA hybridization values of 71.84% and 20.80%, respectively, while genus-level metrics including average amino acid identity (70.9%) and percentage of conserved proteins (52.1%) supported its placement within the genus Parasediminibacterium. Compared with P. paludis HME6815T, strain NIPR152T possessed a larger genome and showed differences in functional gene composition, including relatively higher representation of selected nitrogen-related and hemicellulose-associated functions, whereas P. paludis showed higher densities of several stress- and photoprotection-related genes. The major respiratory quinone was menaquinone-7 (MK-7), and the dominant fatty acids were summed feature 3 (C16:1ω7c and/or C16:1ω6c), iso-C15:0, and C15:1ω6c. The genomic G + C content was 40.38%. Phenotypic, chemotaxonomic, and genotypic characteristics support the classification of strain NIPR152T as representing a novel species of the genus Parasediminibacterium, for which the name Parasediminibacterium schistidii sp. nov. is proposed. The type strain is NIPR152T (= JCM 36343T = KCTC 102165T).

Four endophytic bacterial strains sgz302541T, sgz302542, sgz302552T and sgz302555 were isolated from the rice phyllosphere in Fujian Province, China. Cells were Gram-stain-negative, aerobic, rod-shaped and motile. The optimal growth conditions for all strains were at 30 °C and pH 7.0 without NaCl. Strain sgz302541T showed the highest 16S rRNA gene sequence similarity to Methylobacterium jeotgali S2R03-9T (97.7%), while strain sgz302552T shared the highest similarity with Paraflavitalea soli 5GH32-13T (96.1%). Genome sequencing revealed that the DNA G+C content of sgz302541T was 70.3%, and that of sgz302552T was 40.7%. The ANI values between strain sgz302541T, sgz302552T and their closest strains were 85.9% and 71.0%, respectively. The AAI values between sgz302552T and all genera within the family Chitinophagaceae ranged from 50.5 to 63.9%. The major fatty acids (>10%) of sgz302541T and sgz302552T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c; 70.1%), iso-C15 : 0 (38.0%) and iso-C15 : 1 G (17.2%), respectively. The predominant respiratory quinones for sgz302541T and sgz302552T were Q-10 and MK-7, respectively. Physiological, biochemical, phylogenetic and chemotaxonomic analyses indicated that strains sgz302541T and sgz302552T represent two novel taxa, for which the names Methylobacterium endophyticum sp. nov. (type strain sgz302541T=MCCC 1K09625T=KCTC 8981T) and Endoryza foliicola gen. nov., sp. nov. (type strain sgz302552T (=MCCC 1K09627T=KCTC 102381T) are proposed, respectively.

A Gram-stain-negative, aerobic, non-motile, rod-shaped, and orange-pigmented bacterium, designated CJ426T, was isolated from ginseng soil in Anseong, Korea. Strain CJ426T grew optimally on Reasoner's 2A agar at 30°C and pH 7.0 in the absence of NaCl. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that strain CJ426T belonged to the family Chitinophagaceae and had the highest sequence similarity with Niabella hibiscisoli KACC 18857T (98.7%). The 16S rRNA gene sequence similarities with other members of the genus Niabella ranged from 92.3% to 98.1%. Phylogenomic analyses and overall genomic relatedness indices, including average nucleotide identity, average amino acid identity, and the percentage of conserved proteins values, supported the classification of strain CJ426T as a representative of a novel genus within the family Chitinophagaceae. Furthermore, genome-based analyses suggested that five members of the genus Niabella, including N. aquatica, N. defluvii, N. ginsengisoli, N. hibiscisoli, and, N. yanshanensis, should be separated from other Niabella species and be assigned as a novel genus. The major isoprenoid quinone of strain CJ426T was menaquinone-7 (MK-7). The predominant polar lipids were phosphatidylethanolamine and six unidentified aminolipids. The major fatty acids were iso-C15:0, iso-C15:1 G, and iso-C17:0 3-OH. The genome of strain CJ426T was 6.3 Mbp in size, consisting of three contigs, with a G + C content of 41.9%. Based on a polyphasic taxonomic approach, strain CJ426T represents a novel genus and species within the family Chitinophagaceae, for which the name Paraniabella aurantiaca gen. nov., sp. nov. is proposed. The type strain is CJ426T (= KACC 23908T = JCM 37728T).

A Gram-stain-negative, non-motile, rod-shaped and imazamox-resistant bacterium, designated as H34T, was isolated from soil obtained from a farmland. Strain H34T grew at pH 6.0–9.0 (optimum, 7.0), temperature 15–40 °C (optimum, 30 °C) and salinity of 0–3.0% NaCl (optimum 0.5% NaCl, w/v). Phylogenetic analysis of the 16S rRNA gene and genome sequences showed that strain H34T was affiliated to the family Chitinophagaceae but formed a distinct phyletic branch. The values of 16S rRNA gene sequence similarity, average nt identity (ANI), digital DNA–DNA hybridization (dDDH) and average aa identity (AAI) between strain H34T and closely related type strains of the genera Flavisolibacter, Paraflavisolibacter, Paracnuella, Flaviaesturariibacter and Cnuella were 90.9–92.6%, 68.4–72.1%, 18.7–20.5% and 60.5–65.9%, respectively. The genome size was 7.01 Mb with a G+C content of 56.5 mol%. The major fatty acids (≥10%) were iso-C15 : 0, iso-C15 : 1 G and C16 : 1 ω5c. The only isoprenoid quinone was menaquinone-7. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminophosphoglycolipid, two unidentified phospholipids, three unidentified aminolipids and four unidentified lipids. The distinct phylogenetic relationships; low values of 16S rRNA gene sequence similarity, AAI, ANI and dDDH; and the differences in phenotypic and genotypic characteristics support that strain H34T represents a novel species in a novel genus in the family Chitinophagaceae, for which the name Huijunlia imazamoxiresistens gen. nov., sp. nov. is proposed (type strain H34T=MCCC 1K09117T=KCTC 102287T).

A Gram-negative, orange-colored bacteria, designated BT-541, was isolated from a soil sample in South Korea. Comparative analysis of 16S rRNA gene sequences revealed that the strain BT-541 exhibited the highest sequence similarity with Parasediminibacterium paludis HME6815T (98.50%) and 94.2-93.12% sequence similarity with other members of the family Chitinophagaceae. This strain could grow at temperatures ranging from 15 °C to 37 °C and pH ranging from 6-10. The only respiratory quinone in the bacterial isolate was menaquinone 7 (MK-7), and the major fatty acids were iso-C15:0, iso-C15:1G, and iso-C17:0 3-OH. Polar lipids included a phosphatidylethanolamine, three unidentified aminolipids, three unidentified aminophospholipids, an unidentified phospholipid, and five unidentified lipids. Molecular analysis and phenotypic characteristics indicated that strain BT-541 (KCTC 82123 = JCM 37057 = PQ 898028) could be a potential novel species in the genus Parasediminibacterium.

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.

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).

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).

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

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).

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).

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.

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).

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.

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

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.

A yellow, Gram-stain-positive, strictly aerobic, thermotolerant, non-motile and rod-shaped bacterial strain, designated RY-1T, was isolated from a silt sample of Fuyang River, Wuqiang County, Hengshui City, Hebei Province, PR China. Cells showed oxidase- and catalase-positive activities. Growth occurred at 20-45 °C (optimum, 37 °C) and pH 6.0-8.0 (optimum, pH 7.0), and in the presence of 0-1.5 % (w/v) NaCl (optimum, 0%). A phylogenetic tree based on 16S rRNA gene sequences revealed that strain RY-1T formed a phylogenetic lineage with Flavihumibacter members within the family Chitinophagaceae. A comparison of 16S rRNA gene sequences showed that strain RY-1T was most closely related to Flavihumibacter cheonanensis WS16T (98.6 %), Flavihumibacter sediminis CJ663T (97.7 %) and Flavihumibacter solisilvae 3-3T (97.6 %). The genome size of strain RY-1T was 4.71 Mb, and the DNA G+C content was 44.3 %. The average nucleotide identity, digital DNA-DNA hybridization and average amino acid identity values between strain RY-1T and reference strains were all lower than the threshold values for species delineation. Strain RY-1T contained menaquinone-7 and iso-C15 : 0, iso-C17 : 0 3-OH and iso-C15 : 1G as the sole respiratory isoprenoid quinone and major cellular fatty acids (≥5 %), respectively. The major polar lipids consisted of phosphatidylethanolamine, three unidentified aminolipids and four unidentified lipids. According to the results of phenotypic, phylogenetic and chemotaxonomic characteristics, strain RY-1T represents a novel species of the genus Flavihumibacter, for which the name Flavihumibacter fluminis sp. nov. is proposed. The type strain is RY-1T (=GDMCC 1.2775T=JCM 34870T).

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 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.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00248-023-02215-9.