Crenobacter oryzisoli sp. nov., a novel phosphate-solubilizing bacterium isolated from the paddy soil.

Two Gram-staining-negative, facultative anaerobic, rod-shaped and phosphate-solubilizing strains designated SG2303T and SG2305, were isolated from paddy soil in China. Phylogenetic analysis based on 16 S rRNA gene sequences indicated that SG2303T and SG2305 represented a member of the genus Crenobacter within the family Neisseriaceae of the phylum Pseudomonadota. Strain SG2303T displayed higher 16 S rRNA gene sequence similarities with members of the genus Crenobacter ranging from 93.5 to 94.0%. Strains C. luteus YIM 78141T and C. cavernae K1W11S-77T were closest related to the isolated strains and were considered as type strains. Growth of strain SG2303T occurred at 10-55 °C (optimum 37 °C), pH 5.0-9.0 (optimum pH 6.0-7.0) and 0-1% (w/v) NaCl (optimum 0%). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SG2303T and its closely related taxa were 76.1-78.2% and 20.5-22.1%, respectively. The genomic DNA G + C content was 62.2%. The quinone of strain SG2303T was Q-8. The major fatty acids (> 10%) of strain SG2303T were C16:0 (30.6%), summed feature 3 (C16:1ω7c and/or C16:1ω6c) (26.0%) and C12:0 3OH (12.1%). The polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phospholipids (PL), glycolipid (GL) and unidentified lipids (UL). Based on the results of the phylogenetic, physiological, biochemical, and morphological analysis, strain SG2303T is recognized as a novel species of the genus Crenobacter, for which the name Crenobacter oryzisoli sp. nov. is proposed. The type strain is SG2303T (= GDMCC 1.3970T = JCM 36468T). In addition, SG2303T was also able of phosphorus solubilization and promoting the growth of rice seeds. Strain SG2303T exhibited a relatively high dissolvable phosphorus content of 2.52 µg·mL- 1.

Three Fe(III)-reducing and nitrogen-fixing bacteria, Anaeromyxobacter terrae sp. nov., Anaeromyxobacter oryzisoli sp. nov. and Anaeromyxobacter soli sp. nov., isolated from paddy soil.

Three microaerophilic bacterial strains, designated SG22T, SG63T and SG29T were isolated from paddy soils in PR China. Cells of these strains were Gram-staining-negative and long rod-shaped. SG22T, SG63T and SG29T showed the highest 16S rRNA gene sequence similarities with the members of the genus Anaeromyxobacter. The results of phylogenetic and phylogenomic analysis also indicated that these strains clustered with members of the genus Anaeromyxobacter. The main respiratory menaquinone of SG22T, SG63T and SG29T was MK-8 and the major fatty acids were iso-C15 : 0, iso-C17 : 0 and C16 : 0. SG22T, SG29T and SG63T not only possessed iron reduction ability but also harboured genes (nifHDK) encoding nitrogenase. The genomic DNA G+C contents of SG22T, SG63T and SG29T ranged from 73.3 to 73.5 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) values between SG22T, SG63T and SG29T and the closely related species of the genus Anaeromyxobacter were lower than the cut-off values (dDDH 70 % and ANI 95-96 %) for prokaryotic species delineation. On the basis of these results, strains SG22T, SG63T and SG29T represent three novel species within the genus Anaeromyxobacter, for which the names Anaeromyxobacter terrae sp. nov., Anaeromyxobacter oryzisoli sp. nov. and Anaeromyxobacter soli sp. nov., are proposed. The type strains are SG22T (= GDMCC 1.3185T = JCM 35581T), SG63T (= GDMCC 1.2914T = JCM 35124T) and SG29T (= GDMCC 1.2911T = JCM 35123T).

Two novel Fe(III)-reducing bacteria, Geothrix campi sp. nov. and Geothrix mesophila sp. nov., isolated from paddy soils.

In this research, two novel Fe(III)-reducing bacteria, SG10T and SG198T of genus Geothrix, were isolated from the rice field of Fujian Agriculture and Forestry University in Fuzhou, Fujian Province, China. Strains SG10T and SG198T were strictly anaerobic, rod-shaped and Gram-stain-negative. The two novel strains exhibited iron reduction ability, utilizing various single organic acid as the elector donor and Fe(III) as a terminal electron acceptor. Strains SG10T and SG198T showed the highest 16S rRNA sequences similarities to the type strains of Geothrix oryzisoli SG189T (99.0-99.5%) and Geothrix paludis SG195T (99.0-99.7%), respectively. The phylogenetic trees based on the 16S rRNA gene and genome 120 conserved core genes showed that strains SG10T and SG198T belong to the genus Geothrix. Average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the phylogenetic neighbors and the two isolated strains were 86.1-94.3% and 30.7-59.5%, respectively. The major fatty acids were iso-C15:0, anteiso-C15:0, C16:0 and iso-C13:0 3OH, and MK-8 was the main respiratory quinone. According to above results, the two strains were assigned to the genus Geothrix with the names Geothrix campi sp. nov. and Geothrix mesophila sp. nov. Type strains are SG10T (= GDMCC 1.3406 T = JCM 39331 T) and SG198T (= GDMCC 62910 T = KCTC 25635 T), respectively.

Azotosporobacter soli gen. nov., sp. nov., a novel nitrogen-fixing bacterium isolated from paddy soil.

A nitrogen-fixing strain designated SG130T was isolated from paddy soil in Fujian Province, China. Strain SG130T was Gram-staining-negative, rod-shaped, and strictly anaerobic. Strain SG130T showed the highest 16S rRNA gene sequence similarities with the type strains Dendrosporobacter quercicolus DSM 1736T (91.7%), Anaeroarcus burkinensis DSM 6283T (91.0%) and Anaerospora hongkongensis HKU 15T (90.9%). Furthermore, the phylogenetic and phylogenomic analysis also suggested strain SG130T clustered with members of the family Sporomusaceae and was distinguished from other genera within this family. Growth of strain SG130T was observed at 25-45 °C (optimum 30 °C), pH 6.0-9.5 (optimum 7.0) and 0-1% (w/v) NaCl (optimum 0.1%). The quinones were Q-8 and Q-9. The polar lipids were phosphatidylserine (PS), phosphatidylethanolamine (PE), glycolipid (GL), phospholipid (PL) and an unidentified lipid (UL). The major fatty acids (> 10%) were iso-C13:0 3OH (26.6%), iso-C17:1 (15.6%) and iso-C15:1 F (11.4%). The genomic DNA G + C content was 50.7%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SG130T and the most closely related type strain D. quercicolus DSM 1736T (ANI 68.0% and dDDH 20.3%) were both below the cut-off level for species delineation. The average amino acid identity (AAI) between strain SG130T and the most closely related type strain D. quercicolus DSM 1736T was 63.2%, which was below the cut-off value for bacterial genus delineation (65%). Strain SG130T possessed core genes (nifHDK) involved in nitrogen fixation, and nitrogenase activity (106.38 µmol C2H4 g-1 protein h-1) was examined using the acetylene reduction assay. Based on the above results, strain SG130T is confirmed to represent a novel genus of the family Sporomusaceae, for which the name Azotosporobacter soli gen. nov., sp. nov. is proposed. The type strain is SG130T (= GDMCC 1.3312T = JCM 35641T).

Shouchella tritolerans sp. nov., a facultative anaerobic bacterium isolated from marine sediments.

An alkali, salt, and thermo-tolerant strain designated FJAT-45399T was isolated from marine sediment in Fujian Province, China. Strain FJAT-45399T was Gram-stain-positive, rod-shaped, and facultatively aerobic. It shared high 16S rRNA gene sequence similarities with the members of the genus Shouchella. Further, the phylogenetic and phylogenomic analysis also suggested strain FJAT-45399T clustered with the members of the genus Shouchella. Growth of strain FJAT-45399T was observed at 15-55 °C (optimum 45-50 °C), pH 7.0-13.0 (optimum 9.0) and 0-15% (w/v) NaCl (optimum 2%). It contained MK-7 as the menaquinone. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylglycerol (PG) and an unidentified glycolipid (UGL) and lipid (UL). The major fatty acids (> 10%) were C16:0 (22.8%), iso-C15:0 (21.3%), and anteiso-C15:0 (14.0%). The genomic DNA G + C content was 44.5%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain FJAT-45399T and the most closely related type strain Shouchella clausii DSM 8716T (ANI 94.1% and dDDH 55.4%) were both below the cut-off level for species delineation. Based on the above results, strain FJAT-45399T represents a novel species of the genus Shouchella, for which the name Shouchella tritolerans sp. nov., is proposed. The type strain is FJAT-45399T (= GDMCC 1.3098T = JCM 35613T).

A novel sulfate-reducing and nitrogen-fixing bacterium Fundidesulfovibrio soli sp. nov., isolated from paddy soils.

A strictly anaerobic sulfate-reducing strain, designated SG60T, was isolated from paddy soil collected in Fujian Province, China. Growth of strain SG60T was observed at 20-37 °C, pH 5.5-10.0 and 0-0.7% (w/v) NaCl. Strain SG60T showed the highest 16S rRNA sequence similarities to the type strains of Fundidesulfovibrio magnetotacticus FSS-1T (97.2%) and Fundidesulfovibrio putealis DSM 16056T (96.4%). Phylogenetic trees based on the16S rRNA sequence and genome-based phylogenomic tree constructed using 120 core genes showed that strain SG60T clustered with members of the genus Fundidesulfovibrio. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SG60T and the most closely related type strain F. magnetotacticus were 78.2% and 21.6%, respectively. Strain SG60T contained MK-7 as the main respiratory quinone and anteiso-C15:0, anteiso-C17:1 ω9c, iso-C16:0 and iso-C16:1 H as the major fatty acids. Strain SG60T produced desulfoviridin and possessed genes (nifHDK) encoding functions involved in nitrogen fixation. The genomic DNA G + C content was 65.5%. Based on the observed physiological properties, chemotaxonomic characteristics and ANI and dDDH values, strain SG60T represents a novel species of the genus Fundidesulfovibrio, for which the name Fundidesulfovibrio soli sp. nov. is proposed. The type strain is SG60T (= GDMCC 1.3310T = JCM 35676T).

A novel nitrogen-fixing bacterium, Propionivibrio soli sp. nov. isolated from paddy soil.

A facultative anaerobic nitrogen-fixing bacterium, designated SG131T, was isolated from paddy soil. Strain SG131T showed high 16S rRNA gene sequence similarities with type strains Propionivibrio limicola DSM 6832T (96.9%), Propionivibrio pelophilus asp 66T (96.0%) and Propionivibrio dicarboxylicus DSM 5885T (95.7%). The phylogenetic trees (based on 16S rRNA gene sequences and 120 conserved genes from genomes, respectively) indicated that strain SG131T clustered with members of the genus Propionivibrio. Growth of strain SG131T was observed at 25-40 °C, pH 5.5-10.5 and 0-0.5% (w/v) NaCl. The quinone was Q-7, and the main fatty acids were C16:1 ω6c and/or C16:1 ω7c (25.9%), C16:0 (23.3%), C17:0-cyclo (11.7%), C12:0 (6.0%) and C17:0 (5.9%). The genomic DNA G + C content of strain SG131T was 60.3%. The average nucleotide identity (ANI) values between strain SG131T and its most closely related species P. limicola DSM 6832T, P. pelophilus DSM 12018T and P. dicarboxylicus DSM 5885T were 74.4%, 74.9% and 75.6%, respectively. The digital DNA-DNA hybridization (dDDH) values between strain SG131T and its most closely related species P. limicola DSM 6832T, P. pelophilus DSM 12018T and P. dicarboxylicus DSM 5885T were 19.9%, 20.6% and 20.5%, respectively. All these values were lower than the recommended species delineation thresholds of ANI (95-96%) and dDDH (70%). Strain SG131T possessed core genes (nifHDK) of nitrogen fixation and was confirmed its nitrogen-fixing ability by the ARA method. According to the above-described analysis, strain SG131T represents a novel species of the genus Propionivibrio, for which the name Propionivibrio soli sp. nov. is proposed. The type strain is SG131T (= GDMCC 1.3313T = JCM 35595T).

Genome-based reclassification of Bacillus acidicola, Bacillus pervagus and the genera Heyndrickxia, Margalitia and Weizmannia.

In the present study, the taxonomic positions of Bacillus acidicola, Bacillus pervagus and members of the genera Heyndrickxia, Margalitia and Weizmannia were evaluated. The 16S rRNA gene sequence similarity between Bacillus acidicola DSM 14745T, Bacillus pervagus DSM 23947T and members of the genera Heyndrickxia and Margalitia were above the cut-off level (>95 %) for genus delineation. Amino acid identity (AAI) values and the results of phylogenomic analysis suggested that B. acidicola and the members of the genera Heyndrickxia, Margalitia and Weizmannia belong to the same genus. Furthermore, the AAI and phylogenomic results also differentiate B. pervagus from B. acidicola and the members of the genera Heyndrickxia, Margalitia and Weizmannia. Based on the results, we propose to transfer Bacillus acidicola, Margalitia and Weizmannia to the genus Heyndrickxia. We also propose the reclassification of B. pervagus into a new genus Oikeobacillus gen. nov., with the type species Oikeobacillus pervagus comb. nov.

Lederbergia citrea sp. nov., isolated from citrus rhizosphere.

Three Gram-positive-staining strains FJAT-49754T, FJAT-49682 and FJAT-49731 were isolated from the citrus rhizosphere soil sample. These strains showed the highest 16S rRNA gene sequence similarity with the type strain of Lederbergia panacisoli (97.8-97.9 %). The 16S rRNA gene sequence similarities between strains FJAT-49754T, FJAT-49682, and FJAT-49731 were 99.9 %. The average nucleotide identity (ANI) values between strains FJAT-49754T, FJAT-49682 and FJAT-49731 were above 96 %, while the ANI values with the members of the genus Lederbergia were below 95 %, which were below the cut-off level for prokaryotic species delineation. The above results suggest that strains FJAT-49754T, FJAT-49682 and FJAT-49731 belong to a novel species of the genus Lederbergia. Growth of strain FJAT-49754T was observed at 10-40 °C (optimum at 30 °C, pH 6.0-10.0 (optimum at pH 8.0), and NaCl tolerance up to 7 % (w/v) (optimum at 1 %). MK-7 was the only menaquinone detected in strain FJAT-49754T, and the main polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids of strain FJAT-49754T were anteiso-C15 : 0, iso-C15 : 0, and C16 : 0. The genomic DNA G+C content of strain FJAT-49754T was 38.7 %. Based on the above results, strain FJAT-49754T represents a novel species of the genus Lederbergia, for which the name Lederbergia citrea sp. nov., is proposed. The type strain is FJAT-49754T (=CCTCC AB 2019211T=LMG 31589T).

Geothrix fuzhouensis sp. nov. and Geothrix paludis sp. nov., two novel Fe(III)-reducing bacteria isolated from paddy soil.

Two anaerobic, Fe(III)-reducing and Gram-stain-negative strains, designated SG12T and SG195T, were isolated from paddy soils in Fujian Province, PR China. Phylogenetic trees based on 16S rRNA genes and conserved core genes from genomes indicated that strains SG12T and SG195T clustered with members of the genus Geothrix. The two strains showed the highest 16S rRNA sequences similarities to the type strains of 'Geothrix terrae' SG184T (98.4-99.6 %), 'Geothrix alkalitolerans' SG263T (98.4-99.6 %) and Geothrix fermentans DSM 14018T (98.2-98.8 %). The average nucleotide identity and digital DNA-DNA hybridization values between the two strains and the closely related Geothrix species were 85.1-93.5 % and 29.8-52.9 %, respectively, lower than the cut-off level for prokaryotic species delineation. The menaquinone was MK-8 in both strains. The major fatty acids were iso-C15 : 0, anteiso-C15 : 0 and C16 : 0. Additionally, the two strains possessed iron reduction ability and could utilize organics such as benzene and benzoic acid as electron donors to reduce ferric citrate to ferrous iron. Based on the morphological, biochemical, chemotaxonomic and genome data, the two isolated strains represent two novel species of the genus Geothrix, for which the names Geothrix fuzhouensis sp. nov. and Geothrix paludis sp. nov. are proposed. The type strains are SG12T (=GDMCC 1.3407T=JCM 39330T) and SG195T (= GDMCC 1.3308T=JCM 39327T), respectively.

A novel strictly anaerobic sulfate-reducing diazotrophic bacterium Fundidesulfovibrio terrae sp. nov., isolated from paddy soil.

A strictly anaerobic sulfate-reducing strain, designated SG127T, was isolated from paddy soil. SG127T showed the highest 16S rRNA gene sequence similarity to the type strain of Fundidesulfovibrio magnetotacticus (98.2 %). A phylogenetic tree based on 16S rRNA gene sequences indicated that SG127T clustered with members of the genus Fundidesulfovibrio. Growth of SG127T was observed at 20-37 °C (optimum, 30 °C), pH 5.5-9.0 (optimum, 7.0-8.0) and with 0-0.2 % (w/v) NaCl (optimally without NaCl). SG127T contained MK-7 as the only menaquinone and anteiso-C15 : 0, anteiso-C17 : 1ω9c, C18 : 0, iso-C14 : 0, iso-C15 : 0, iso-C16:0, iso-C16 : 1H, iso-C18 : 1H and summed feature nine as the major fatty acids. The genomic DNA G+C content of SG127T was 64.6 %. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between SG127T and the closely related Fundidesulfovibrio magnetotacticus were 78.5% and 23.2 %, respectively, which were lower than the cut-off values (ANI 95-96% and dDDH 70 %) for prokaryotic species delineation. SG127T had desulfoviridin, possessed nitrogen fixation genes (nifHDK) and actively fixed nitrogen according to the acetylene reduction assay. On the basis of these results, strain SG127T represents a novel species of the genus Fundidesulfovibrio, for which the name Fundidesulfovibrio terrae sp. nov. is proposed. The type strain is SG127T (= GDMCC 1.3137T = JCM 35589T).

Isolation and genomics of ten novel Shewanella species from mangrove wetland.

Mangrove bacteria largely compose the microbial community of the coastal ecosystem and are directly associated with nutrient cycling. In the present study, 12 Gram-negative and motile strains were isolated from a mangrove wetland in Zhangzhou, China. Pairwise comparisons (based on 16S rRNA gene sequences) and phylogenetic analysis indicated that these 12 strains belong to the genus Shewanella. The 16S rRNA gene sequence similarities among the 12 Shewanella strains and their related type strains ranged from 98.8 to 99.8 %, but they still could not be considered as known species. The digital DNA-DNA hybridization (dDDH) and average nucleotide identity (ANI) values between the 12 strains and their related type strains were below the cut-off values (ANI 95-96% and dDDH 70 %) for prokaryotic species delineation. The DNA G+C contents of the present study strains ranged from 44.4 to 53.8 %. The predominant menaquinone present in all strains was MK-7. The present study strains (except FJAT-53532T) also contained ubiquinones (Q-8 and Q-7). The polar lipid phosphatidylglycerol and fatty acid iso-C15 : 0 was noticed in all strains. Based on phenotypic, chemotaxonomic, phylogenetic and genomic comparisons, we propose that these 12 strains represent 10 novel species within the genus Shewanella, with the names Shewanella psychrotolerans sp. nov. (FJAT-53749T=GDMCC 1.2398T=KCTC 82649T), Shewanella zhangzhouensis sp. nov. (FJAT-52072T=MCCC 1K05363T=KCTC 82447T), Shewanella rhizosphaerae sp. nov. (FJAT-53764T=GDMCC 1.2349T=KCTC 82648T), Shewanella mesophila sp. nov. (FJAT-53870T=GDMCC 1.2346T= KCTC 82640T), Shewanella halotolerans sp. nov. (FJAT-53555T=GDMCC 1.2344T=KCTC 82645T), Shewanella aegiceratis sp. nov. (FJAT-53532T=GDMCC 1.2343T=KCTC 82644T), Shewanella alkalitolerans sp. nov. (FJAT-54031T=GDMCC 1.2347T=KCTC 82642T), Shewanella spartinae sp. nov. (FJAT-53681T=GDMCC 1.2345T=KCTC 82641T), Shewanella acanthi sp. nov. (FJAT-51860T=GDMCC 1.2342T=KCTC 82650T) and Shewanella mangrovisoli sp. nov. (FJAT-51754T=GDMCC 1.2341T= KCTC 82647T).

Two novel alkalitolerant species Pseudalkalibacillus spartinae sp. nov. and Pseudalkalibacillus sedimenti sp. nov.

In this study, two novel alkalitolerant strains (FJAT-53046T and FJAT-53715T) were isolated from sediment samples collected in Zhangzhou, PR China. Phylogeny based on 16S rRNA gene sequences suggested that strains FJAT-53046T and FJAT-53715T were new members of the genus Pseudalkalibacillus. The two novel strains showed the highest 16S rRNA gene sequence similarity to Pseudalkalibacillus hwajinpoensis DSM 16206T, with values of 97.4 and 97.6 %, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between the two strains and the reference strain were 77.2 and 79.6 %, 20.9 and 30.2 %, respectively, which were below the prokaryotic species delineation thresholds. The ANI and dDDH values between strains FJAT-53046T and FJAT-53715T were 86.0 and 30.2 %, respectively, suggesting that they belonged to different species in the genus Pseudalkalibacillus. The major respiratory quinone in both strains was MK-7 and the major cellular fatty acids were anteiso-C15 : 0 and anteiso-C17 : 0. Diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine were the major polar lipids in both novel strains. Combined with results stemming from the determination of physical and biochemical characteristics, chemical properties, and genome analysis, strains FJAT-53046T and FJAT-53715T are proposed to represent two novel species of the genus Pseudalkalibacillus, for which the names Pseudalkalibacillus spartinae sp. nov. and Pseudalkalibacillus sedimenti sp. nov. are proposed. The type strains are FJAT-53046T (=GDMCC 1.3077T=JCM 35611T) and FJAT-53715T (=GDMCC 1.3076T=JCM 35610T), respectively.

Cytobacillus citreus sp. nov., isolated from citrus rhizosphere soil.

A Gram-stain-positive, rod-shaped and motile strain, designated FJAT-49705T, was isolated from the citrus rhizosphere soil sample. Strain FJAT-49705T grew at 20-40 °C (optimum, 30 °C) and pH 6.0-11.0 (optimum, pH 7.0) with 0-5 % (w/v) NaCl (optimum, 2 %). Strain FJAT-49705T showed high 16S rRNA gene sequence similarity to 'Bacillus dafuensis' FJAT-25496T (99.7 %) and Cytobacillus solani FJAT-18043T (98.0 %). In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic trees (based on 71 bacterial single-copy genes), strain FJAT-49705T clustered with the members of the genus Cytobacillus. MK-7 was the only isoprenoid quinone present. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and an unidentified phospholipid. The major fatty acids were anteiso-C15 : 0 and iso-C15 : 0. The genomic DNA G+C content was 36.9 %. The average nucleotide identity (ANI) values between FJAT-49705T and 'B. dafuensis' FJAT-25496T and C. solani FJAT-18043T were below the cut-off level (95-96 %) recommended as the ANI criterion for interspecies identity. Based on the above results, strain FJAT-49705T represents a novel species of the genus Cytobacillus, for which the name Cytobacillus citreus sp. nov. is proposed. The type strain is FJAT-49705T (=CCTCC AB 2019243T= LMG 31580T).

Geothrix oryzisoli sp. nov., a ferric iron-reducing bacterium isolated from paddy soil.

An anaerobic, Gram-staining-negative, rod-shaped, Fe(III)-reducing strain, designated SG189T, was isolated from paddy soil in Fujian Province, China. Growth occurred at 20-35 ℃ (optimum 30 ℃), pH 6.5-8.0 (optimum 7.0) and 0-0.2% (w/v) NaCl (optimum 0%). The strain SG189T showed the highest 16S rRNA sequences similarities to the type strains of Geothrix fermentans DSM 14018T (98.9%), "Geothrix terrae" SG184T (99.0%) and "Geothrix alkalitolerans" SG263T (99.3%). ANI and dDDH values between strain SG189T and the most closely related Geothrix species were 86.5-87.1% and 31.5-32.9%, which lower than the cut-off values (ANI 95-96% and dDDH 70%) for prokaryotic species delineation. Further, genome-based phylogenomic trees constructed using 81 core genes (UBCG2) and 120 conserved genes (GTDB) showed that strain SG189T formed a clade with members of the genus Geothrix. The menaquinone was shown to be MK-8, and the major fatty acids were iso-C15:0 and iso-C13:0 3OH. The genomic DNA G + C content was 68.2%. Additionally, we found that strain SG189T possessed ability to reduce ferric iron, and strain SG189T could reduce 10 mM of ferric citrate in 10 days with lactate as the sole electron donor. Based on the observed physiological and biochemical properties, chemotaxonomic characteristics, ANI and dDDH values, SG189T represents a novel species of the genus Geothrix, for which the name Geothrix oryzisoli sp. nov. is proposed. The type strain is SG189T (= GDMCC 1.3408T = JCM 39324T).

Sulfurospirillum oryzae sp. nov., A Novel Nitrogen-Fixing Bacterium Isolated from Paddy Soil.

An anaerobic, Gram-staining-negative, rod shaped, nitrogen-fixing strain designed SG202T, was isolated from paddy soil collected from Fujian Province in China. Strain SG202T showed the highest 16S rRNA gene sequence similarity with the type strain Sulfurospirillum multivorans DSM 12446T (98.5%). Phylogenetic trees based on 16S rRNA gene sequences and conserved core genes from genomes indicated that strain SG202T branched with members of the genus Sulfurospirillum. Growth was observed at 25-37 °C (optimum 30 °C), pH 6.0-10.5 (optimum 7.5), and 0-0.6% (w/v) NaCl (optimum 0.2%). Strain SG202T contained MK-6 as the menaquinone and C16:1ω7c (40.6%), C16:0 (33.3%), C18:1ω7c (13.6%) and C14:0 (9.0%) as the major fatty acids. The genomic DNA G+C content was 39.0%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SG202T and its closely related species S. multivorans DSM 12446T, Sulfurospirillum halorespirans DSM 13726T, Sulfurospirillum arsenophilum DSM 10659T and Sulfurospirillum diekertiae ACSDCET were 81.3, 81.5, 84.4, 82.2% and 24.5, 24.5, 27.9, 25.2%, respectively. All these values were lower than the recommended species delineation thresholds of ANI (95-96%) and dDDH (70%). Strain SG202T possessed core genes (nifHDK) of nitrogen fixation, and nitrogenase activities (3470.45 µmol C2H4 g-1 protein h-1) was examined using the acetylene reduction assay. Based on the observed physiological properties, chemotaxonomic characteristics and genome analysis, strain SG202T is recognized as a novel species of the genus Sulfurospirillum, for which the name Sulfurospirillum oryzae sp. nov. is proposed. The type strain is SG202T (= GDMCC 1.3379T= JCM 35596T).

Bacillus litorisediminis sp. nov., a Thermophilic Bacterium Isolated from Mangrove Sediment.

Two aerobic, Gram-staining-positive, rod-shaped, endospore-forming, thermophilic bacterial strains, designated FJAT-47801T and FJAT-47835, were isolated from the sediment collected from Zhangjiang Estuary Mangrove National Nature Reserve in Fujian Province, China. Growth was observed at 25-55 °C (optimum, 50 °C) and pH 7.0-9.0 (optimum, pH 7.0), with up to 4.0% (w/v) NaCl (optimum, without NaCl). Strains FJAT-47801T and FJAT-47835 showed the highest 16S rRNA gene sequence similarity to Bacillus oleivorans (98.5%). The 16S rRNA gene sequence similarity between FJAT-47801T and FJAT-47835 was 99.9% indicating they were the same species. Phylogenetic (based on 16S rRNA gene sequences) and phylogenomic (based on 120 conserved bacterial single-copy genes) trees showed that strains FJAT-47801T and FJAT-47835 should be affiliated to the genus Bacillus. The of menaquinone of strain FJAT-47801T was MK-7. The major fatty acids of strain FJAT-47801T were iso-C15:0, anteiso-C15:0, iso-C17:0, and C16:0. The major polar lipids strain FJAT-47801T were phosphatidylethanolamine (PE), diphosphatidylglycerol (DPG), and phosphatidylglycerol (PG). The genomic DNA G+C content of strain FJAT-47801T was 39.3%. The average nucleotide identity (84.3%) and the digital DNA-DNA hybridization value (28.1%) between strain FJAT-47801T and B. oleivorans CCTCC AB 2013353T were below the cut-off level for species delineation. Based on the above results, strain FJAT-47801T represents a novel species of the genus Bacillus, for which the name Bacillus litorisediminis sp. nov., is proposed. The type strain is FJAT-47801T (=GDMCC 1.2712T = JCM 34875T).

Fundidesulfovibrio agrisoli sp. nov., A Nitrogen-Fixing Bacterium Isolated from Rice Field.

A strictly anaerobic nitrogen-fixing strain, designated SG106T, was isolated from rice field. The 16S rRNA gene sequence analysis showed that strain SG106T was closely related to the type strain of Fundidesulfovibrio magnetotacticus (97.3%). In phylogenetic (based on 16S rRNA gene sequences) and phylogenomic (constructed using a concatenated alignment of 117 conserved bacterial single-copy genes with GTDB-Tk) trees, strain SG106T clustered with members of the genus Fundidesulfovibrio. Strain SG106T grew at 20-40 °C and 0-0.4% (w/v) NaCl. Desulfoviridin was found in the strain SG106T. The genomic DNA G + C content of strain SG106T was 66.0%. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between strain SG106T and the closely related F. magnetotacticus were 78.4% and 21.7%, respectively. Genome analysis showed that strain SG106T encodes genes for nitrogen fixation (nifHDK). Acetylene reduction experiments showed that the nitrogenase activity of strain SG106T could reach 224.7 µmol C2H4 g-1 protein h-1. Based on the above results, strain SG106T represents a novel species of the genus Fundidesulfovibrio, for which the name Fundidesulfovibrio agrisoli sp. nov. is proposed. The type strain is SG106T (= GDMCC 1.3136T = JCM 35588T).

Neobacillus rhizophilus sp. nov. and Neobacillus citreus sp. nov., isolated from the citrus rhizosphere soil.

Two Gram-staining positive strains, FJAT-49825T and FJAT-50051T were isolated from a citrus rhizosphere soil sample. Strains FJAT-49825T and FJAT-50051T showed the highest 16S rRNA gene sequence similarity with the type strain of Neobacillus cucumis (98.4-98.5%). The 16S rRNA gene sequence similarity between strains FJAT-49825T and FJAT-50051T was 99.8%. Strain FJAT-49825T optimally grew at 35 °C, pH 6.0 in the absence of NaCl while strain FJAT-50051T grew at 40 °C, pH 7.0 and in presence of 2% NaCl (w/v). Both strains contained meso-2,6-diaminopimelic acid as the cell-wall diamino acid. The respiratory quinone of strains FJAT-49825T and FJAT-50051T was MK-7. The polar lipids of strain FJAT-49825T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified aminolipid and unidentified lipid whereas strain FJAT-50051T polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified phospholipid and unidentified lipid. The major fatty acids (> 10%) in both strains were iso-C15:0 and anteiso-C15:0. The genomic DNA G + C content of strains FJAT-49825T and FJAT-50051T were 40.8 and 41.1%, respectively. The average nucleotide identity and digital DNA-DNA hybridization value between strains FJAT-49825T and FJAT-50051T and with other members of the genus Neobacillus were lower than the cut-off value (95-96/70%) for interspecies identity. Based on the results, strains FJAT-49825T and FJAT-50051T represent two novel species of the genus Neobacillus, for which the names Neobacillus rhizophilus sp. nov. and Neobacillus citreus sp. nov. are proposed. The type strains are FJAT-49825T (= GDMCC 1.2592T = JCM 34834T) and FJAT-50051T (= GDMCC 1.2593T = JCM 34835T).

Two ferric-reducing bacteria Geothrix terrae sp. nov. and Geothrix alkalitolerans sp. nov., isolated from paddy soil.

Two Gram-staining-negative strains, designated SG184T and SG263T were isolated from paddy soils in Fujian Province, China. The 16S rRNA gene sequence similarities between strains SG184T, SG263T, and the related type strain Geothrix fermentans DSM 14018T were 98.6% and 99.1%, respectively. The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) between the two strains and G. fermentans DSM 14018T were below the cut-off level (95% for ANI and 70% for dDDH) recommended as the criterion for interspecies taxon affiliation. Further, phylogenetic and phylogenomic trees indicated that strains SG184T and SG263T clustered with the member of the genus Geothrix. The menaquinone was MK-8, and the main fatty acids were iso-C15:0 and iso-C13:0 3OH. The genomic DNA G + C content of SG184T and SG263T was 68.07% and 68.05%, respectively. Additionally, two strains had iron reduction ability and could reduce ferrihydrite to ferrous iron. Based on the morphological, biochemical, chemotaxonomic and genome analysis, the two isolated strains represent two novel species of the genus Geothrix, for which the names Geothrix terrae sp. nov. and Geothrix alkalitolerans sp. nov. are proposed. The type strains are SG184T (= GDMCC1.3134 T = JCM39321T) and SG263T (= GDMCC 1.3316 T = JCM 39325T), respectively.