Terrihabitans rhizophilus sp. nov., isolated from the rhizosphere soil of plant in temperate semi-arid steppe

A bacterial strain PJ23T was isolated from the rhizosphere soil of Elymus dahuricus Turcz. sampled from a temperate semi-arid steppe in the northern of Inner Mongolia Autonomous Region, China. The strain is Gram-stain-negative, aerobic, light-pink, short rod-shaped, and non-spore-forming. Cell growth could be observed at 4-29℃ (optimal at 24℃), pH 6.0-8.6 (optimal at 8.0) and in the presence of 0-5.0% (w/v) NaCl (optimal at 2.5%). The major cellular fatty acids of strain PJ23T were Summed feature 8 (C18:1 ω6c and/or C18:1 ω7c) (39.42%) and C16:0 (9.60%). The polar lipids were phosphatidylcholine, two unidentified glycolipids, one unidentified aminophospholipid, and two other unidentified polar lipids. The major respiratory quinone was ubiquinone-10. Phylogeny analysis based on 16S rRNA gene sequences retrieved from the genomes showed that, the strain was closely related to the species Terrihabitans soli IZ6T and Flaviflagellibacter deserti SYSU D60017T, with the sequence similarities of 96.79% and 96.15%, respectively. The G + C content was 65.23 mol% calculated on draft genome sequencing. Between the strains PJ23T and Terrihabitans soli IZ6T, the average nucleotide identity (ANI), amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) was 73.39%,71.12% and 15.7%, these values were lower than the proposed and generally accepted species boundaries of ANI, AAI and dDDH, respectively. Based on phenotypic, chemotaxonomic, and phylogenetic characteristics, strain PJ23T represents a novel species of Terrihabitans, for which the name Terrihabitans rhizophilus sp. nov. is proposed. The type strain is PJ23T (= KCTC 92977 T = CGMCC 1.61577 T).

Marinobacter albus sp. nov., Isolated from Sand Sediment in a Coastal Intertidal Zone

A Gram-stain-negative bacterium with a rod-to-ovoid shape, named strain M216T, was isolated from sand sediment from the coastal intertidal zone of Huludao, Liaoning Province, China. Growth was observed at 8-40 °C (optimal, 30 °C), pH 5.5-9.5 (optimal, pH 6.5) and 0.5-14.0% (w/v) NaCl (optimal, 6%). Strain M216T possessed ubiquinone-9 as its sole respiratory quinone and phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, one unidentified aminophosphoglycolipid, one unidentified aminophospholipid, two unidentified phosphoglycolipids, three unidentified phospholipids and three unidentified glycolipids as the main polar lipids. C12:0, C16:0, C12:0 3-OH, C16:1 ω9c, C18:1 ω9c and summed features 3 (C16:1 ω7c and/or C16:1 ω6c) were the major fatty acids (> 5%). The 16S rRNA gene sequence of strain M216T exhibited high similarity to those of 'Marinobacter arenosus' CAU 1620T and Marinobacter adhaerens HP15T (99.3% and 98.5%, respectively) and less than 98.5% similarity to those of the other type strains. The ANI and dDDH values between the strain M216T and 'Marinobacter arenosus' CAU 1620T were 87.4% and 33.3%, respectively; these values were the highest among the other type strains but lower than the species threshold. The G+C content of strain M216T was 58.3%. Genomic analysis revealed that strain M216T harbors the major CAZymes of GH13, GH23, GH73, and PL5, which are responsible for polysaccharide degradation and the potential ability to reduce nitrate to ammonia. Through phenotypic, genotypic, and chemotaxonomic analyses, we proposed the name Marinobacter albus sp. nov., a novel species in the genus Marinobacter, with its type strain M216T (= MCCC 1K08600T = KCTC 82894T).

Marinobacter azerbaijanicus sp. nov., a moderately halophilic bacterium from Urmia Lake, Iran

A novel moderately halophilic, Gram-stain-negative and facultatively anaerobic bacterium, designated as strain TBZ242T, was isolated from water of Urmia Lake in the Azerbaijan region of Iran. The cells were found to be rod-shaped and motile by a single polar flagellum, producing circular and yellowish colonies. The strain could grow in the presence of 0.5-10 % (w/v) NaCl (optimum, 2.5-5 %). The temperature and pH ranges for growth were 15-45 °C (optimum 30 °C) and pH 7.0-11.0 (optimum pH 8.0) on marine agar. The 16S rRNA gene sequence analysis revealed that strain TBZ242T belonged to the genus Marinobacter, showing the highest similarities to Marinobacter algicola DG893T (98.8 %), Marinobacter vulgaris F01T (98.8 %), Marinobacter salarius R9SW1T (98.5 %), Marinobacter panjinensis PJ-16T (98.4 %), Marinobacter orientalis W62T (98.0 %) and Marinobacter denitrificans JB2H27T (98.0 %). The 16S rRNA and core-genome phylogenetic trees showed that strain TBZ242T formed a distinct branch, closely related to a subclade accommodating M. vulgaris, M. orientalis, M. panjinensis, M. denitrificans, M. algicola, M. salarius and M. iranensis, within the genus Marinobacter. Average nucleotide identity and digital DNA-DNA hybridization values between strain TBZ242T and the type strains of the related species of Marinobacter were ≤85.0 and 28.6 %, respectively, confirming that strain TBZ242T represents a distinct species. The major cellular fatty acids of strain TBZ242T were C16 : 0 and C16 : 1  ω7c/C16 : 1 ω6c and the quinone was ubiquinone Q-9. The genomic DNA G+C content of strain TBZ242T is 57.2 mol%. Based on phenotypic, chemotaxonomic and genomic data, strain TBZ242T represents a novel species within the genus Marinobacter, for which the name Marinobacter azerbaijanicus sp. nov. is proposed. The type strain is TBZ242T (= CECT 30649T = IBRC-M 11466T). Genomic fragment recruitment analysis showed that this species prefers aquatic saline environments with intermediate salinities, being detected on metagenomic databases of Lake Meyghan (Iran) with 5 and 18 % salinity, respectively.

Marinobacter panjinensis sp. nov., a moderately halophilic bacterium isolated from sea tidal flat environment

Two moderately halotolerant bacterium strains, designated PJ-16^T and PJ-38, were isolated from a tidal flat of the red beach in Panjin City, Liaoning Province, PR China. Cells were found to be Gram-stain-negative, aerobic, motile, rod-shaped with a single polar flagellum. Optimum growth of strain PJ-16^T occurred at 30 °C, pH 7.0 and 0.2-8.0  % (w/v) NaCl, and strain PJ-38 at 30 °C, pH 6.0-7.0 and 0.2-8.0  % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain PJ-16^T was most closely related to Marinobacter denitrificans KCTC 62941^T (99.2 % 16S rRNA gene sequence similarity), Marinobacter algicola DSM 16394^T (98.6 %), Marinobacter salarius JCM 19399^T (98.4 %) and Marinobacter confluentis KCTC 42705^T (98.2 %), and strain PJ-38 was most closely related to M. denitrificans KCTC 62941^T (99.1 %), M. algicola DSM 16394^T (98.6 %), M. salarius JCM 19399^T (98.4 %) and M. confluentis KCTC 42705^T (98.1 %). The G+C content of the genomic DNA of strain PJ-16^T based on its draft genomic sequence was 57.4 mol%. The major cellular fatty acids of strain PJ-16^T were C_16 : 0, C_16 : 1  ω7c/C_16 : 1  ω6c and C_18 : 1  ω9c. The major respiratory quinone of PJ-16^T was ubiquinone-9 and the major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The results of the phenotypic, phylogenetic and genomic analyses revealed that strains PJ-16^T and PJ-38 represent a novel species of the genus Marinobacter, and the name Marinobacter panjinensis sp. nov. is proposed. The type strain is PJ-16^T (= CGMCC 1.13694^T= KCTC 72023^T).

Sandaracinobacteroides sayramensis sp. nov., a yellow-pigmented bacterium isolated from lake water

A Gram-negative, non-motile, facultatively anaerobic, rod-shaped bacterium, designated strain RS1-74^T, was isolated from the surface water of Sayram Lake, Xinjiang Uygur Autonomous Region, China. The strain was able to grow optimally at 30 °C and pH 7.0-7.5, and in the presence of 0-0.5 % (v/w) NaCl. Catalase and oxidase activities were present. H₂S was produced. Chemotaxonomic analysis showed Q-10 was the sole respiratory quinone. The polar lipids were composed of phosphatidylethanolamine, diphosphatidylglycerol, two glycolipids, phosphatidylglycerol, sphingoglycolipid and two unidentified lipids. Summed feature 3 (C_16 : 1  ω7c and/or C_16 : 1  ω6c) and summed feature 8 (C_18 : 1  ω7c and/or C_18 : 1  ω6c) were the predominant fatty acids. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain RS1-74^T was closely related to 'Sandaracinobacter neustonicus' JCM 30 734 (98.65 %), 'Sandaracinobacter sibiricus' RB16-17 (98.42 %) and Sandaracinobacteroides hominis SZY PN-1^T (97.09%). The genomic DNA G+C content was 66.45 mol%. The average nucleotide identity and DNA-DNA hybridization values among the genomes of strain RS1-74^T and 'Sandaracinobacter neustonicus' JCM 30734 and Sandaracinobacteroides hominis SZY PN-1^T were 78.2 and 77.22 %, and 22.2 and 20.40 %, respectively. Based on the physiological, biochemical, phylogenetic and genomic data, strain RS1-74^T represents a novel species within the genus Sandaracinobacteroides, for which the name Sandaracinobacteroides sayramensis sp. nov. is proposed, with type strain RS1-74^T (=KCTC 82674^T=MCCC 1K06282^T).

Marinobacter shengliensis subsp. alexandrii Subsp. Nov., Isolated from Cultivable Phycosphere Microbiota of Highly Toxic Dinoflagellate Alexandrium catenella LZT09 and Description of Marinobacter shengliensis Subsp. shengliensis Subsp. Nov

Phycosphere hosts the boundary of unique holobionts harboring dynamic algae-bacteria interactions. During our investigating the microbial consortia composition of phycosphere microbiota (PM) derived from diverse harmful algal blooms (HAB) dinoflagellates, a novel rod-shaped, motile and faint yellow-pigmented bacterium, designated as strain LZ-6 ^T, was isolated from HAB Alexandrium catenella LZT09 which produces high levels paralytic shellfish poisoning toxins. Phylogenetic analysis based on 16S rRNA gene and two housekeeping genes, rpoA and pheS sequences showed that the novel isolate shared the highest gene similarity with Marinobacter shengliensis CGMCC 1.12758 ^T (99.6%) with the similarity values of 99.6%, 99.9% and 98.5%, respectively. Further phylogenomic calculations of average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strains LZ-6 ^T and the type strain of M. shengliensis were 95.9%, 96.4% and 68.5%, respectively. However, combined phenotypic and chemotaxonomic characterizations revealed that the new isolate was obviously different from the type strain of M. shengliensis. The obtained taxonomic evidences supported that strain LZ-6 ^T represents a novel subspecies of M. shengliensis, for which the name is proposed, Marinobacter shengliensis subsp. alexandrii subsp. nov. with the type strain LZ-6 ^T (= CCTCC AB 2018388T^T = KCTC 72197 ^T). This proposal automatically creates Marinobacter shengliensis subsp. shengliensis for which the type strain is SL013A34A2^T (= LMG 27740 ^T = CGMCC 1.12758 ^T).

Marinobacter caseinilyticus sp. nov., Isolated from Saline Soil

A Gram-stain-negative, motile, aerobic, rod-shaped bacterium with flagella, designated M3-13^T, was isolated from a saline soil in Zhoushan, China. According to phylogenetic analysis based on 16S rRNA gene sequences, strain M3-13^T was assigned to the genus Marinobacter with highest 16S rRNA gene sequence similarity of 97.7% to Marinobacter maroccanus LMG 30466^T, followed by Marinobacter sediminum R65 ^T (97.5%) and M. salsuginis SD-14B^T (97.2%). Digital DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) were determined to evaluate the genomic relationship between strain M3-13^T and M. maroccanus LMG 30466^T. Digital DDH estimation (19.8%) as well as ANI (72.98%) proved the dissimilarity of strain M3-13^T. Optimal growth of the strain M3-13^T was at 28-30 °C and at pH 8.0-8.5, in the presence of 3-6% (w/v) NaCl. The major fatty acids detected in strain M3-13^T were C_16:1 ω7c/C_16:1 ω6c, C_16:0, C_18:1ω7c/C_18:1 ω6c and C_12:03-OH, and the predominant respiratory quinone was ubiquinone-9. The major polar lipids included diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophosphoglycolipid and one unidentified phosphoglycolipid. The DNA G+C content was 56.6%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain M3-13^T belongs to the genus Marinobacter. Based on the polyphasic taxonomic characterization, strain M3-13^T is considered to represent a novel species of the genus Marinobacter, for which the name Marinobacter caseinlyticus sp. nov. is proposed (type strain M3-13^T = MCCC 1K04560^T = KCTC 72043^T).

Aerophototrophica crusticola gen. nov., sp. nov., isolated from desert biocrusts

A pink-pigmented, Gram-stain-negative, rod-shaped, strictly aerobic bacterial strain MIMtkB3^T, was isolated from moss crusts in Hunshandake desert of China. Cells grew at 15-45 °C (optimum of 28 °C), at pH of 6.0-8.5 (optimum of 7.0) and with 0-1.0 % (w/v) NaCl (optimum of 0 %). The strain could biosynthesize the green-coloured pigment bacteriochlorophyll a (BChl a). The respiratory quinone was ubiquinone Q-10, while C_18 : 1 ω7c and C_18 : 1 2OH were the major fatty acids. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, an unidentified aminophospholipid, one unidentified phospholipid, three unidentified glycolipid and one unidentified lipid were the major polar lipids. Strain MIMtkB3^T was most closely related to Oleisolibacter albus NAU-10^T, Niveispirillum fermenti CC-LY736^T, and Rhodocista centenaria SW of the family Rhodospirillaceae with 16S rRNA gene similarities of 93.09, 92.02 and 91.73%, respectively. The genomic DNA G+C content calculated on complete genome sequencing was 69.3 mol%. The average nucleotide identity between strain MIMtkB3^T and its closely related type strains in Rhodospirillaceae was below 77.96 % and digital DNA-DNA hybridization lower than 24.70 %. Full light utilization pathway of aerobic anoxygenic phototrophic bacteria was identified in the genome. Based on phenotypic, chemotaxonomic and phylogenetic characteristics, strain MIMtkB3^T represents a novel genus of the family Rhodospirillaceae, for which the name Aerophototrophica crusticola gen. nov., sp. nov. is proposed. The type strain is MIMtkB3^T (=KCTC 42633^T=MCCC 1K00570^T).

Marinobacter changyiensis, sp. nov., isolated from offshore sediment

An aerobic, Gram-stain-negative bacterium, designated CLL7-20^T, was isolated from a marine sediment sample from offshore of Changyi, Shandong Province, China. Cells of strain CLL7-20^T were rod-shaped, motile with one or more polar flagella, and grew optimally at pH 7.0, at 28 °C and with 3 % (w/v) NaCl. The principal fatty acids of strain CLL7-20^T were C_16 : 0 and summed feature 3 (C_16 : 1 ω7c/C_16 : 1 ω6c). The main polar lipids of strain CLL7-20^T were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and an unidentified aminolipid (AL). Strain CLL7-20^T contained Q-9 as the major respiratory quinone. The G+C content of its genomic DNA was 56.2 mol%. Phylogenetically, strain CLL7-20^T branched within the genus Marinobacter, with M. daqiaonensis YCSA40^T being its closest phylogenetic relative (96.7 % 16S rRNA gene sequence similarity), followed by M. sediminum R65^T (96.6 %). Average nucleotide identity and in silico DNA-DNA hybridization values between strain CLL7-20^T and the closest related reference strains were 73.2% and 19.8 %, respectively. On the basis of its phenotypic, phylogenetic and chemotaxonomic characteristics, we suggest that strain CLL7-20^T (=MCCC 1A14855^T=KCTC 72664^T) is the type strain of a novel species in the genus Marinobacter, for which the name Marinobacter changyiensis sp. nov. is proposed. Based on the genomic analysis, siderophore genes were found from strain CLL7-20^T, which indicate its potential as a promising alternative to chemical fertilizers in iron-limitated environments such as saline soils.

Marinobacter denitrificans sp. nov., isolated from marine sediment of southern Scott Coast, Antarctica

A novel bacterium, designated JB02H27^T, was isolated from marine sediment collected from the southern Scott Coast, Antarctica. Cells were Gram-stain-negative, facultatively anaerobic, polar-flagellated and motile rods. Growth occurred at 4-45 °C, at pH 7.0-9.0 and with 3-25 % (w/v) NaCl. Phylogenetic trees based on 16S rRNA gene sequences showed that strain JB02H27^T consistently fell within the genus Marinobacter and formed a clade together with Marinobacter algicola DG893^T (98.8 % similarity), Marinobacter confluentis KCTC 42705^T (98.4 %), Marinobacter salarius R9SW1^T (98.4%) and Marinobacter halotolerans CP12^T (97.9 %), which were subsequently used as reference strains for comparisons of phenotypic and chemotaxonomic characteristics. Average nucleotide identity values between strain JB02H27^T and the four related type strains were 80.9, 76.6, 81.9 and 76.3 %, respectively. The major fatty acids were summed feature 3, C_16 : 0, C_18 : 1 ω9c and C_16 : 0 N alcohol. The polar lipids included phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, and an unidentified phospholipid, aminolipid, aminophospholipid and glycolipids. The sole respiratory quinone was ubiquinone-9. The DNA G+C content was 56.9 mol%. Based on the genomic, phylogenetic, phenotypic and chemotaxonomic analysis, we propose that strain JB02H27^T represents a novel species of the genus Marinobacter, for which the name Marinobacter denitrificans sp. nov. is proposed. The type strain is JB02H27^T (=GDMCC 1.1528^T=KCTC 62941^T).

Hymenobacter crusticola sp. nov., isolated from biological soil crust

A Gram-stain-negative, aerobic, light-pink, short rod-shaped, non-spore-forming bacterial strain was isolated from biological soil crust sampled in the Hopq Desert, Inner Mongolia, China, designated MIMBbqt21^T. The G+C content of the genomic DNA was 55.1 mol%. Phylogenetic analysis of the 16S rRNA gene sequence showed that strain MIMBbqt21^T belonged to the genus Hymenobacter and had the highest sequence similarity to Hymenobacter cavernaeK1E01-27^T (94.35 %). Cell growth could be observed at 4-29 °C (optimum, 24 °C), pH of 6.0-8.6 (optimum, 6.0) and in the presence of 1 % (w/v) NaCl (optimum, 0 %). The major fatty acids of strain MIMBbqt21^T were iso-C15 : 0, C16 : 1ω5c and summed feature 3 (C16 : 1ω7c/C16 : 1ω6c). The main polar lipids were phosphatidylethanolamine, five unidentified aminophospholipids, an unidentified glycolipid and four unidentified polar lipids. The sole respiratory quinone was menaquinone MK-7. Based on the results of the phylogenetic, chemotaxonomic and phenotypic studies, strain MIMBbqt21^T could be distinguished from all known Hymenobacter species and represents a novel species, for which the name Hymenobactercrusticola sp. nov. is proposed. The type strain is MIMBbqt21^T (=MCCC 1K01312^T=KCTC 42804^T).