Unknown Polar Lipids Research Articles

Hyunsoonleella ulvae sp. nov., isolated from algae in China.

A novel Gram-stain-negative, aerobic, non-motile, rod-shaped and yellow-pigmented bacterial strain, designated HU1-3T, was isolated from Ulva in China. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain HU1-3T represented a member of the genus Hyunsoonleella within the family Flavobacteriaceae, phylum Bacteroidota, and showed the highest 16S rRNA gene sequence similarity to Hyunsoonleella flava T58T (97.6 %). Strain HU1-3T grew at 15-35 °C (optimum, 25-30 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 2-6 % (w/v) NaCl (optimum, 2-4 %). The draft genome of strain HU1-3T comprised 4.1 Mbp with a G+C content of 33.9mol%. Compared with the reference strain Hyunsoonleella jejuensis CNU004T, the average nucleotide identity value of strain HU1-3T was 77.9 %. The major fatty acids (>10 % of the total) were iso-C15 : 0, iso G-C15 : 1 and iso-C17 : 0 3-OH. MK-6 was the major respiratory quinone. The major polar lipids were phosphatidylethanolamine, two unidentified aminolipids, and three unknown polar lipids. Many genes that encode glycoside hydrolases (e.g. glucosidase, xylosidase, mannosidase, galactosidase, etc.) were annotated in the genome of strain HU1-3T, which indicated that it might have the ability to degrade various kinds of polysaccharides. Given the phylogenetic, chemotaxonomic, biochemical and genomic data, strain HU1-3T is considered to represent a novel species of the genus Hyunsoonleella, for which the name Hyunsoonleella ulvae sp. nov. is proposed. The type strain is HU1-3T (=KCTC 82511T=MCCC 1K05798T).

Qipengyuania pacifica sp. nov., a Novel Carotenoid-Producing Marine Bacterium of the Family Erythrobacteraceae, Isolated from Sponge (Demospongiae), and Antimicrobial Potential of Its Crude Extract

A marine Alphaproteobacterium designated as strain NZ-96T was isolated in February 2021, from a sponge species (Demospongiae) collected in muddy sediments with boulders and old chimneys in Otago/Canterbury Slope, Pacific Ocean, New Zealand. The isolate was found to be Gram-negative, rod-shaped, aerobic, motile, and produced yellow-colored colonies. The isolate was positive for alkaline phosphatase, leucine arylamidase, trypsin, catalase, and oxidase and negative for α-galactosidase and urease. It was resistant to many antibiotics including hygromycin, trimethoprim, spectinomycin, ampicillin, oxytetracycline, cephalosporin, bacitracin, and polymyxin. The 16S rRNA gene-based phylogenetic analyses exhibited that strain NZ-96T belonged to the genus Qipengyuania and showed 98.3–98.8% 16S rRNA gene sequence similarity to its closest relatives. The major respiratory quinone was ubiquinone-10 (Q-10). The polar lipid profile consisted of phosphatidylcholine, sphingoglycolipid, phosphatidylglycerol, one unknown polar lipid, and three unknown glycolipids. The major fatty acids were C18:1ω12t, C16:0, C16:1ω7c, C17:1ω6c, C16:02-OH, and C14:0 2-OH. Carotenoid were produced. The crude extract showed pronounced activity against Staphylococcus aureus Newman and Bacillus subtilis DSM 10. Pairwise ANI and dDDH values of strain NZ-96T and closely related phylogenetic hits were below the threshold values of 95% and 70%, respectively. Genes for trehalose biosynthesis, aspartate-semialdehyde dehydrogenase, flagellar biosynthesis, fatty acid biosynthesis, and antibiotics resistance were present, which aids in isolate survival in a sea or ocean environment. The DNA G+C content was 60.8% (by genome). Based on data obtained by the polyphasic approach, strain NZ-96T (= DSM 112811T = NCCB 100842T) represents a novel species of the genus Qipengyuania, for which the name Qipengyuania pacifica sp. nov. is proposed.

Algiphilus acroporae sp. nov. and Coraliihabitans acroporae gen. nov. sp. nov., isolated from scleractinian coral Acropora digitifera.

Two Gram-staining-negative, aerobic, rod-shaped bacteria NNCM1T and NNCM2T were isolated from the scleractinian coral Acropora digitifera. NNCM1T grew with 0.5-12 % (w/v) NaCl (optimum, 3-6 %), at 18-37 °C (optimum, 28 °C) and at pH 6.0-10.0 (optimum, 7.0-8.0). NNCM2T grew with 0.5-10 % (w/v) NaCl (optimum, 2 %), at 18-37 °C (optimum, 28 °C) and at pH 6.5-9.0 (optimum, 7.0). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that NNCM1T formed a lineage within the genus Algiphilus of the family Algiphilaceae, and it was distinct from the most closely related species Algiphilus aromaticivorans DG1253T, with a 16S rRNA gene sequences similarity of 97.05 %. NNCM2T formed a lineage within the family Rhodobacteraceae, and it was distinct from the closely related genera Limibaculum halophilum CAU 1123T, Paroceanicella profunda D4M1T and Pseudoruegeria aestuarii MME-001T with 93.41, 92.78 and 91.09% identities, respectively. The major respiratory quinone was Q-8 and Q-10 for NNCM1T and NNCM2T, respectively. The predominant fatty acids (more than 10 %) were summed feature 8 (39.4 %) and C16 : 0 (19.4 %) for NNCM1T and summed feature 8 (62.8 %) and C16 : 0 (12.4 %) for NNCM2T. The DNA G+C contents of NNCM1T and NNCM2T were 63.3 and 63.4 mol% respectively. The polar lipids of NNCM1T comprised one diphosphatidylglycerol, one phosphatidylethanolamine, one phosphatidylglycerol and one unknown polar lipid, while those of NNCM2T comprised one phosphatidylethanolamine, one phosphatidylglycerol, one aminolipid and four unknown polar lipids. Phenotypic characteristics (physiological, biochemical and chemotaxonomic) also supported the taxonomic novelty of the two isolates. Thus, NNCM1T is considered to represent a novel species within genus Algiphilus, for which the name Algiphilus acroporae sp. nov. is proposed. The type strain is NNCM1T (=KCTC 82966T=MCCC 1K06445T). NNCM2T represents a novel genus and species within the family Rhodobacteraceae, for which the name Coraliihabitans acroporae gen. nov. sp. nov. is proposed. The type strain is NNCM2T (=KCTC 82967T=MCCC 1K06408T).

Pacificimonas pallium sp. nov., an Isolated Bacterium from the Mantle of Pacific Oyster Crassostrea gigas in Germany, and Prediction of One-Carbon Metabolism

A yellow bacterium from marine agar, strain WHA3T, was isolated from the mantel of the Pacific oysters Crassostrea gigas in the Wilhelmshaven Sea in northern Germany. Based on the 16S rRNA gene sequence, strain WHA3T had a high similarity to Pacificimonas flava JLT2015T (95.80%) and 94.79% to Pacificimonas aurantium JLT2012T. Furthermore, the dDDH and ANI value analysis between WHA3T and other closest type strains were lower than 70% and 95%, respectively. The percentage of conserved proteins (POCP) and the average amino acid identity (AAI) value against Pacificimonas flava JLT2015T and Pacificimonas aurantium JLT2012T represented in the ranges of higher than 50% and 60%, respectively. Strain WHA3T contained ubiquinone-10 (Q-10) as the predominant quinone, and the major fatty acids were C16:1 ω7c and C18:1 ω7c. Granules of polyhydroxyalkanoates (PHAs) were absent. The main polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, several sphingoglycolipids, an unknown phospholipid, an unknown glycolipid, and an unknown polar lipid. The polyamines contained spermidine and spermine. The DNA G + C content of strain WHA3T was 61.69%. An analysis of the whole-genome sequence in the frame of genome mining strain WHA3T predicted the presence of genomes for one-carbon metabolism, TonB-dependent transporters, vitamin B12 transporter, iron siderophore receptor protein, and other genes, some of which play important roles against restricted nutrient sources. The extract of strain WHA3T moderately inhibited the growth of Candida albicans DSM 1665. The polyphasic taxonomic analysis results suggested that strain WHA3T could be separated from its closest type strains. Strain WHA3T represents a novel species in the genus Pacificimonas, for which we propose the name Pacificimonaspallium sp. nov., with the type strain WHA3T (= DSM 111825T = NCCB 100832T).

Paenibacillus caui sp. nov., a nitrogen-fixing species isolated from the rhizosphere soil of a peach tree.

A nitrogen-fixing, endospore-forming, motile, rod-shaped, facultative aerobic bacterium, designated 81-11T, was isolated from rhizosphere soil of a peach tree collected from Handan, Hebei, PR China. From the comparison of 16S rRNA gene sequence, the strain is most closely related to Paenibacillus phoenicis DSM 27463T (96.9 %) and Paenibacillus faecis DSM 23593T (96.7 %). The genome size of strain 81-11T was 4.4 Mb, comprising 4879 predicted genes with a DNA G+C content of 50.0 mol%. The average nucleotide identity values of genome sequences between the novel isolate and the type strains of related species P. phoenicis DSM 27463T and P. faecis DSM 23593T were 71.8 and 72.1 %, respectively. The major cellular fatty acids were anteiso-C15 : 0(47.8 %), iso-C16 : 0 (15.5 %) and iso-C15 : 0 (13.0 %). Menaquinone-7 was the major respiratory quinone. The polar lipids contained phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid, aminoglycopid, unknown polar lipids and unidentified aminophosphoglycolipid. Based on phylogenetic, genomic and phenotypic characteristics, strain 81-11T was classified as a novel species within the genus Paenibacillus, for which the name Paenibacillus caui sp. nov. is proposed. The type strain of Paenibacillus caui is 81-11T (=JCM 34618T=CGMCC 1.18907T).

Flavobacterium coralii sp. nov., a marine bacterium isolated from coral culture seawater.

A Gram-stain-negative, non-motile, strictly aerobic, rod-shaped bacterium, with one polar flagellum and named D11R37T, was isolated from coral culture seawater of Acropora digitifera. Strain D11R37T grew with 0-6 % (w/v) NaCl (optimum, 0.5%), at 10-41 °C (optimum, 28 °C) and at pH 6.0-7.0 (optimum, 7.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain D11R37T formed a lineage within the genus Flavobacterium, and it was distinct from the most closely related species Flavobacterium suzhouense XIN-1T and Flavobacterium suaedae G16-7T with 16S rRNA gene sequences similarities of 95.97% and 95.48 %. The major respiratory quinone was menaquinone-6. The polar lipids comprised one phosphatidylethanolamine, two aminolipids and one unknown polar lipid. The predominant fatty acids (more than 10 % of total fatty acids) were iso-C15 : 0 (18.0%), iso-C17 : 0 3-OH (11.9 %) and summed feature 3 (10.9 %). The DNA G+C content was 41.3 mol%. Based on polyphasic taxonomic data, strain D11R37T is considered to represent a novel species within the genus Flavobacterium, for which the name Flavobacterium coralii sp. nov. is proposed. The type strain is D11R37T (=KCTC 82968T=MCCC 1K06440T).

Alteriqipengyuania abyssalis sp. nov., a Novel Member of the Class Alphaproteobacteria Isolated from Sponge, and Emended Description of the Genus Alteriqipengyuania

A novel Gram-negative, aerobic, motile, lemon-yellow-colored, and non-spore-forming rod-shaped bacterium designated strain NZ-12BT was isolated in February 2021 from a sponge species (Crateromorpha) collected at the southern Kermadec Ridge, Pacific Ocean, New Zealand. Comparative 16S rRNA gene-based analyses indicated that strain NZ-12BT shared 98.58%, 96.44%, 96.23%, and 94.78% 16S rRNA sequence similarity to Alteriqipengyuania lutimaris S-5T, Qipengyuania pelagi UST081027-248T, Qipengyuania citreus RE35F/1T, and Alteriqipengyuania halimionae CPA5T, respectively. The major respiratory quinone was ubiquinone-10(Q-10). The polar lipid profile of NZ-12BT was composed of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidyl-N-methyl-ethanolamine, phosphatidylcholine, sphingoglycolipid, phosphatidylglycerol, one unknown polar lipid, three unknown phospholipids, and three unknown glycolipids. The major fatty acids of strain NZ-12BT were C18:1ω12t, C16:0, C17:1ω6c, and C14:02-OH. Carotenoids were present. Genome mining analysis revealed a biosynthetic gene cluster encoding for the terpene biosynthesis. Pairwise ANI and dDDH values of strain NZ-12BT and closely related phylogenetic neighbors were below the threshold values of 95% and 70%, respectively. The DNA G+C content was 65.4 mol% (by genome). Based on data obtained by a polyphasic approach, type strain NZ-12BT (=DSM 112810T = NCCB 100841T) represents a novel species of the genus Alteriqipengyuania, for which the name Alteriqipengyuania abyssalis sp. nov. is proposed.

Nesterenkonia sedimenti sp. nov., isolated from marine sediment.

A Gram-staining-positive actinobacteria strain, designated MY13T, was isolated from deep-sea sediment of the western Pacific Ocean and subjected to a taxonomic polyphasic investigation. Based on the results, cells were aerobic, irregular short rod, non-motile and non-spore-forming. Colonies were cream, circular, smooth, convex, opaque and 1.0-2.0mm in diameter after growth on MZ2 medium at 40°C for 72h. Strain MY13T grew at 4-50°C (optimum, 40°C), pH 7-12 (pH 9) and 0.5-15% (w/v) NaCl (3.5%). The 16S rRNA gene sequence analysis revealed that strain MY13T is affiliated with the genus Nesterenkonia and closely related to Nesterenkonia populi GP10-3T (96.6%). Digital DNA-DNA hybridization (dDDH) values and average nucleotide identity (ANI) differentiated it from its closest relatives, with values ranging from 19.8% to 22.4% and 72.6% to 78.0%, respectively. Chemotaxonomic analysis showed that the major menaquinone of strain MY13T was MK-7; major cellular fatty acids were anteiso-C17:0, anteiso-C15:0 and iso-C16:0; whole-cell sugars were galactose and xylose; the peptidoglycan type was L-Lys-Gly-D-Asp; and polar lipids were diphosphatidylglycerol, phosphatidylglycerol, two unknown glycolipids, one unknown polar lipid and two unknown lipids. The G+C content of genomic DNA was 63.1mol%. Based on the physiological, chemotaxonomic and phylogenetic data, strain MY13T is a novel species of the genus Nesterenkonia, for which the name Nesterenkonia sedimenti sp. nov. is proposed. The type strain is MY13T (= LMG 28111T = MCCC 1A09979T = JCM 19767T = CGMCC 1.12784T).

Marinisubtilis pacificus gen. nov., sp. nov., a Member of the Family Microbacteriaceae Isolated From a Deep-Sea Seamount.

A Gram-stain-positive, yellow, aerobic, slender rod-shaped bacterial strain, designated KN1116T, was isolated from a deep-sea seamount. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain KN1116T was related to the genus Chryseoglobus and had highest 16S rRNA gene sequence identity with Chryseoglobus frigidaquae CW1T (98.5%). The predominant cellular fatty acids were anteiso-C15:0 and iso-C16:0. The quinone system for strain KN1116T comprised menaquinone MK-12, MK-11, MK-10 and MK-13. The polar lipid profile contained diphosphatidylglycerol, phosphatidylglycerol, six unknown glycolipids, two unidentified phospholipids and one unknown polar lipid. The cell-wall peptidoglycan of strain KN1116T was of the type B1β, containing 2,4-diaminobutyric acid as the diamino acid. Genome sequencing revealed the strain KN1116T has a genome size of 2.7 Mbp and a G+C content of 69.4mol%. Based on phenotypic, chemotaxonomic, phylogenetic and genomic data, strain KN1116T represents a novel species of a novel genus of the family Microbacteriaceae, for which the name Marinisubtilis pacificus gen. nov., sp. nov. is proposed. The type strain of Marinisubtilis pacificus is KN1116T (=CGMCC 1.17143T =KCTC 49299T).

Bruguierivorax albus gen. nov. sp. nov. Isolated from Mangrove Sediment and Proposal of Bruguierivoracaceae fam. nov

A novel Gram-negative, motile, aerobic rod-shaped bacterium designated BGMRC 2031T was isolated from mangrove sediment collected from Guangxi Province, China. Optimal growth occurred at 28 °C and pH 7.0–8.0 in the presence of 1% (w/v) NaCl. Alignment based on 16S rRNA gene sequences indicated that strain BGMRC 2031T is most closely related to Sodalis praecaptivus HS1T (95.6%, sequence similarity), followed by Biostraticola tofi DSM 19580T (95.5%), Sodalis glossinidius DSM 16929T (95.4%), and Brenneria goodwinii FRB141T (94.9%) sequence similarity. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain BGMRC 2031T formed a distinct branch in a robust cluster and revealed that strain BGMRC 2031T, genera Biostraticola and Sodalis, formed a novel family-level clade in the order Enterobacterales. The novel strain showed an average nucleotide similarity of 74.7%, 74.2%, and 73.1% for S. praecaptivus HS1T, S. glossinidius DSM 16929T, and B. tofi DSM 19580T, respectively. The genomes of the BGMRC 2031T shared the presence of a riboflavin synthesis gene cluster. The menaquinones of strain BGMRC 2031T were MK-8 and Q-8, which were similar to those of genus Biostraticola. The major fatty acids (> 10%) were C16:0 (19.9%), summed feature 2 (iso-C16:1 and/or C14:0 3-OH, 18.10%), summed feature 3 (C16:1ω7c and/or C16:1ω6c, 15.3%), C12:0 (13.9%), C17:0 cyclo (11.4%), and C14:0 (10.4%). The main polar lipids were phosphatidyl methylethanolamine, phosphatidyl glycerol, diphosphatidyl glycerol, phosphatidyl inositol, one unidentified phospholipid, and one unknown polar lipid. The G+C content of strain BGMRC 2031T was 55.4%. Strain BGMRC 2031T could extend the mean lifespan and maximum lifespan of Caenorhabditis elegans by 4.5% and 12.5%, respectively. Overall, the results of this study indicate that BGMRC 2031T is a novel species in a new genus, for which the name Bruguierivorax albus gen. nov. sp. nov. is proposed, and the type of strain is designated as BGMRC 2031T (= NBRC 111907T = KCTC 52119T). In addition, a novel family, Bruguierivoracaceae fam. nov., is proposed to accommodate the genera Bruguierivorax, Biostraticola, and Sodalis.

Arachidicoccus soli sp. nov., a bacterium isolated from soil.

A Gram-stain-negative, aerobic, non-motile and rod-shaped bacterium, designated KIS59-12T, was isolated from a soil sample collected on Hodo island, Boryeong, Republic of Korea. The strain grew at 10-33 °C, pH 6.0-7.5 and with 0-4 % NaCl (w/v). Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain KIS59-12T was in the same clade as Arachidicoccus rhizosphaerae Vu-144T and Arachidicoccus ginsenosidivorans Gsoil809T with 97.5 and 97.2 % sequence similarity, respectively. Comparative genome analysis between strain KIS59-12T and A. rhizosphaerae Vu-144T showed that average nucleotide identity value was 69.4 % and the digital DNA-DNA hybridization value was 19.1 %. The major respiratory quinone was menaquinone-7. The major polar lipids were phosphatidylethanolamine and an unknown polar lipid. The predominant cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and iso-C17 : 0 3-OH, which supported the affiliation of strain KIS59-12T with the genus Arachidicoccus. The major polyamines were homospermidine and putrescine. The genomic DNA G+C content was 36.4 mol%. On the basis of phylogenetic, physiological and chemotaxonomic characteristics, strain KIS59-12T represents a novel species of the genus Arachidicoccus, for which the name Arachidicoccus soli sp. nov. is proposed. The type strain of Arachidicoccus soli is KIS59-12T (=KACC 17340T=NBRC 113161T).

Flavobacterium profundi sp. nov., isolated from a deep-sea seamount.

The Gram-stain-negative, rod-shaped, facultative anaerobic, motile bacterial strain, designated TP390T, was isolated from a seamount near the Yap Trench in the tropical western Pacific. Phylogenetic analysis based on 16S rRNA gene sequence showed that strain TP390T was related to the genus Flavobacterium and had highest 16S rRNA gene sequence identity with the type strain of Flavobacterium jejuense EC11T (97.8 %). Sequence similarities to all other type strains of current species of the genus Flavobacterium were below 97 %. The predominant cellular fatty acids were iso-C15 : 0 and iso-C15 : 1G. The quinone system for strain TP390T comprised predominantly menaquinone MK-6 and the polar lipid profile contained phosphatidylethanolamine, four unknown aminolipids, one glycolipid and six unknown polar lipids. The genomic DNA G+C content of strain TP390T was 31.2 mol%. In addition, the maximum values of in silico DNA-DNA hybridization (isDDH) and average nucleotide identity (ANI) between strain TP390T with F. jejuense KCTC 42149T were 22.60 and 80.01% respectively. Combined data from phenotypic, phylogenetic, isDDH and ANI data demonstrated that the strain TP390T is representative of a novel species of the genus Flavobacterium, for which we propose the name Flavobacterium profundi sp. nov. (type strain TP390T=KACC 18559T=CGMCC 1.15398T).

Paenibacillus solisilvae sp. nov., isolated from birch forest soil.

A Gram-stain-positive, motile, rod-shaped bacterium, designated strain LAM7113T, was isolated from soil sample collected from a birch forest in Xinjiang Uygur Autonomous Region, PR China. Strain LAM7113T grew optimally at pH 8.0, 30 °C and in the presence of 1.0 % NaCl (w/v). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain LAM7113T was closely related to members of the genus Paenibacillus, with the highest similarity to Paenibacillus baekrokdamisoli Back-11T (96.2 %). The genomic DNA G+C content was 43.4 mol%. The values of average nucleotide identity and DNA-DNA hybridization were 66.1 and 27.0 %, respectively, by comparing the draft genome sequences of strain LAM7113T and P. baekrokdamisoli Back-11T. Anteiso-C15 : 0 and iso-C15 : 0 were identified as the major cellular fatty acids. Menaquinone-7 was detected as the predominant respiratory quinone. The major polar lipids were found to be diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol, three unidentified aminophospholipids, three unidentified glycolipids, one unidentified phospholipid and two unknown polar lipids. Based on its phenotypic, phylogenetic and chemotaxonomic characteristics, strain LAM7113T is proposed to represent a novel species of the genus Paenibacillus with the name Paenibacillus solisilvae sp. nov. The type strain is LAM7113T (=CGMCC 1.16619T=JCM 32513T).

Mesorhizobium alexandrii sp. nov., isolated from phycosphere microbiota of PSTs-producing marine dinoflagellate Alexandrium minutum amtk4.

An aerobic, Gram-stain-negative, motile and rod-shaped bacterial strain, designated as Z1-4T, was isolated from the phycosphere microbiota of marine dinoflagellate Alexandrium minutum that produces paralytic shellfish poisoning toxins. Phylogenetic analysis based on 16S rRNA gene sequences showed that the new isolate belongs to the genus Mesorhizobium, and it was closely related to Mesorhizobium waimense LMG 28228T and Mesorhizobium amorphae LMG 18977T with both 16S rRNA gene sequence similarities of 97.3%. The values of average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) relatedness between strain Z1-4T and its relatives are both well below the thresholds used for the delineation of a new species. A genome-based phylogenetic tree constructed by up-to-date bacterial core gene set (UBCG) indicates that strain Z1-4T forms an independent branch within the genus Mesorhizobium. The respiratory quinone of strain Z1-4T was Q-10. The major fatty acids were similar to other members of the genus Mesorhizobium containing the summed feature 8, C16:0, C19:0cycloω8c, C17:0 and summed feature 3. The polar lipids are phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, an unidentified aminophospholipid, five glycolipids and seven unknown polar lipids. The DNA G + C content was determined to be 62.1mol% based on its genomic sequence. Combined evidences based on the genotypic, chemotaxonomic and phenotypic characteristics clearly indicates that strain Z1-4T represents a novel species of the genus Mesorhizobium, for which the name Mesorhizobium alexandrii sp. nov. is proposed. The type strain is Z1-4T (= KCTC72512T = CCTCC AB 2019101T).

Altererythrobacter rhizovicinus sp. nov., isolated from rhizosphere soil of Haloxylon ammodendron.

A salt-tolerant, Gram-negative, rod-shaped and yellow-pigmented bacterium, designated strain AY-3RT, was isolated from rhizosphere soil of a desert xerophyte, Haloxylon ammodendron, sampled at Badain Jaran Desert, Alxa region, Inner Mongolia, PR China. Growth of this strain was observed at 20-42 °C (optimum, 28-30 °C), at pH 6.0-9.0 (optimum, pH 6.0-7.0) and at 0-8 % (w/v) NaCl (optimum, 3 %). Results of phylogenetic analysis based on 16S rRNA gene sequences showed that strain AY-3RT was a member of the genus Altererythrobacter, with the highest similarity to Altererythrobacter aerophilus Ery1T (97.6 %), followed by Altererythrobacter xinjiangensis S3-63T (96.9 %). The predominant fatty acids (>10.0 %) were C18 : 1ω7c, C17 : 1ω6c and summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, sphingoglycolipid and one unknown polar lipid. The predominant respiratory quinone was ubiquinone-10. The G+C content of the genomic DNA of strain AY-3RT was 66.3 mol%. On the basis of the data from this polyphasic taxonomic study, strain AY-3RT represents a novel species of the genus Altererythrobacter, named Altererythrobacter rhizovicinus sp. nov. (=MCCC 1K03572T=KCTC 72280T).

Deinococcus psychrotolerans sp. nov., isolated from soil on the South Shetland Islands, Antarctica.

A Gram-stain-negative, non-motile, strictly aerobic, coccus-shaped bacterium, designated S14-83T, was isolated from a soil sample collected from the South Shetland Islands of Antarctica. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain is a novel member of the genus Deinococcus, with Deinococcus alpinitundrae as its closest relative (96.1 % similarity). The DNA G+C content of the strain was 61.1 mol% and the major respiratory quinone was MK-8. Major cellular fatty acids were summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) and C16 : 0. As well as containing glycophospholipid, aminophospholipids and glycolipid as major polar lipids, there were also some unknown polar lipids. The diagnostic diamino acid in the cell-wall peptidoglycan was ornithine, corroborating the assignment of the strain to the genus Deinococcus. Strain S14-83T was shown to be extremely resistant to gamma radiation (>10 kGy) and UV light (460 Jm-2). On the basis of phylogenetic, chemotaxonomic and phenotypic data presented here, strain S14-83T represents a novel species of the genus Deinococcus, for which the name Deinococcus psychrotolerans sp. nov. is proposed. The type strain is S14-83T (=CCTCC AB 2015449T= DSM 105285 T).

Facilibium subflavum gen. nov., sp. nov. and Cysteiniphilum halobium sp. nov., new members of the family Fastidiosibacteraceae isolated from coastal seawater

Two Francisella-like bacteria, designated strains SYSU SYW-5T and SYSU SYW-6T, were isolated from coastal seawater sampled at Huizhou Double-Moon Bay, Guangdong Province, PR China. Cells were found to be Gram-stain-negative, non-motile, non-spore-forming and of pleomorphic shape (coccobacilli or rod). Chemotaxonomic analysis of the plasma membrane revealed ubiquinone-8 as the respiratory quinone, and saturated branched-chain (anteiso-C15 : 0) and saturated straight-chain (C18 : 0) fatty acids as major components (>8 % of total fatty acid). The major polar lipids comprised diphosphatidylglycerol (cardiolipin), phosphatidylethanolamine, phosphatidylglycerol and phosphatidylcholine, as well as an unidentified aminophospholipid and an unidentified phospholipid in SYSU SYW-5T, and two unknown polar lipids in SYSU SYW-6T. Comparison of 16S rRNA gene sequences showed that SYSU SYW-5T had maximum similarity to Fastidiosibacter lacustris SYSU HZH-2T (93.4 %), while SYSU SYW-6Thad maximum similarity to Cysteiniphilum litorale SYSU D3-2T (97.5 %). Phylogenetic dendrograms based on 16S rRNA genes and 31 concatenated protein markers revealed that the two novel strains represent a distinct lineage within the family Fastidiosibacteraceae. The average nucleotide identity and in silico DNA-DNA hybridization values between the two isolates and their related species were well below the threshold limit for species delineation (<89.2 and <35 %, respectively). Based on the above results, strain SYSU SYW-5T is proposed to be a novel species of a new genus with the name Facilibium subflavum gen. nov., sp. nov. (SYSU SYW-5T = DSM 103991T= KCTC 52556T), and strain SYSU SYW-6T is proposed to be a novel species of genus Cysteiniphilum with the name Cysteiniphilumhalobium sp. nov. (SYSU SYW-6T=DSM 103992T=KCTC 52558T).

Marinomonas flavescens sp. nov., isolated from seawater adjacent to Fildes Peninsula, Antarctica.

A Gram-negative bacterium, namely strain ANRC-JHZ47T, was isolated from a seawater sample collected at Biological Bay, Fildes Peninsula, Antarctica. Cells of strain ANRC-JHZ47T were rod-shaped and motile by a single polar flagellum. Strain ANRC-JHZ47T was aerobic, oxidase-negative, and catalase-positive. The strain grew at 4-37 °C (optimum, 25 °C), pH at 3.5-10.0 (optimum, pH 5.5) and in NaCl at 1-7.0 % (w/v; optimum, 2-3 %). Strain ANRC-JHZ47T used Q-8 as the predominant respiratory quinone. Its predominant fatty acids were C16 : 0 (21.9 %), C12 : 0 (12.6 %), C19 : 0cyclo ω8c (12.4 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 13.1 %), C10 : 0 3-OH (11.3 %) and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 6.0 %). Its major polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, one unidentified aminolipid and five unknown polar lipids. The DNA G+C content was 42.6 mol%. Strain ANRC-JHZ47T showed the highest 16S rRNA gene sequence similarity to Marinomonas arenicola KMM 3893T (97.9 %), followed by Marinomonas primoryensis KMM 3633T (97.6 %), Marinomonas profundimaris D104T (97.2 %) and Marinomonas pollencensis IVIA-Po-185T (97.0 %). Furthermore, the average nucleotide identity values between strain ANRC-JHZ47T and M. arenicola KMM 3893T, M. primoryensis KMM 3633T and M. profundimaris D104T were 79.8, 74.0, and 74.1 %, respectively. The in silico DNA-DNA hybridization values between them were 22.5±2.5, 20.4±2.3 and 19.9±2.3 %, respectively. Based on the results of phenotypic and phylogenetic analyses, strain ANRC-JHZ47T is considered to represent a novel species of the genus Marinomonas, for which the name Marinomonas flavescens sp. nov. is proposed. The type strain is ANRC-JHZ47T (=MCCC 1K03604T=KCTC 72113T).

Pedobacter chinensis sp. nov., a cellulose-decomposing bacterium from Arctic tundra soil.

A novel bacterial strain, JDX94T, was isolated from tundra soil sampled north of the Yellow River station, Arctic. Cells were Gram-stain-negative, non-spore-forming, short rod-shaped and aerobic. The strain displayed growth at 4-37 °C with an optimum at 28 °C, with 0-1.0 % (w/v) NaCl (optimum, 0%) and at pH 6.0-9.0 (optimum, pH 7.0-7.5). Cells contained summed feature 3 (comprising C16 : 1ω7c and/or C16 : 1ω6c), iso-C15 : 0 and iso-C17 : 0 3-OH as its major cellular fatty acids and menaquinone-7 as the only respiratory quinone. The polar lipid profile of strain JDX94T consisted of phosphatidylethanolamine, two unidentified aminolipids and four unknown polar lipids. The DNA G+C content was 37.5 mol%. On the basis 16S rRNA gene sequence comparison, strain JDX94T showed the highest sequence similarity (96.7 %) to Pedobacteragri JCM 15120T, followed by Pedobacteralluvionis DSM 19624T (96.3 %). Furthermore, the average nucleotide identity and digital DNA-DNA hybridization values between strain JDX94T and related species of the genus Pedobacter were 74.6-79.2 % and 18.9-24.5 %, respectively. Based on the presented results, we propose a novel species for which the name Pedobacterchinensis sp. nov. is suggested, with the type strain JDX94T (=MCCC 1H00335T= KCTC 62850T).

Amphritea opalescens sp. nov., isolated from sediment adjacent to Fildes Peninsula, Antarctica

A taxonomic study was carried out on a Gram-stain-negative bacterium, namely strain ANRC-JH13T, isolated from a sediment sample collected at Jasper beach, adjacent to Fildes Peninsula, Antarctica. Cells of strain ANRC-JH13T were non-spore-forming rods and motile by the way of flagellum. Strain ANRC-JH13T was facultatively anaerobic, oxidase-positive, and catalase-positive. Growth of strain ANRC-JH13T occurred at 10-42 °C (optimum, 28 °C), pH 4.0-11.0 (pH 7.0) and 0-12.0 % (w/v) NaCl (1.0-2.0 %). Its predominant fatty acids were C16 : 0 (21.7 %), summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c; 38.3 %), and summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 20.1 %). Isoprenoid quinone Q-8 was the major respiratory quinone. Its major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, and four unknown polar lipids. The DNA G+C content was 48 mol%. Strain ANRC-JH13T showed the highest 16S rRNA gene sequence similarity to Amphritea balenae JAMM 1525T (97.9 %), followed by Amphritea atlantica M41T (97.8 %) and Amphritea japonica JAMM 1866T (97.3 %), and formed a lineage within the genus Amphritea on the phylogenetic trees. However, the in silico average nucleotide identity values between strain ANRC-JH13T and A. balenae JAMM 1525T, A. atlantica M41T, and A. japonica JAMM 1866T were 74.0, 76.7, and 74.9 %, respectively. The in silico DNA-DNA hybridization values between them were 19.8, 20.6, and 19.4 %, respectively. Based on the results from phenotypic, chemotaxonomic, and phylogenetic analyses, strain ANRC-JH13T is considered to represent a novel species of the genus Amphritea, for which the name Amphriteaopalescens sp. nov. is proposed. The type strain is ANRC-JH13T (=MCCC 1K03512T=KCTC 62532T).