Fan-Xu Meng

Altererythrobacter atlanticus sp. nov., isolated from deep-sea sediment.

A Gram-stain-negative, short rod-shaped bacterium, designated 26DY36(T), was isolated from a deep-sea sediment sample collected from the North Atlantic Rise. The isolate required NaCl and grew best with 2 % (w/v) sea salts at a temperature of 30-35 °C and at pH 7.0. It formed yellow colonies, produced carotenoid-like pigments and did not produce bacteriochlorophyll a. Strain 26DY36(T) was positive for hydrolysis of aesculin, gelatin, tyrosine and Tweens 20, 40, 60 and 80, but negative for hydrolysis of casein, DNA and starch. The major respiratory quinone was ubiquinone-10. The major polar lipid profile consisted of sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and two unidentified glycolipids. The principal fatty acids (>5 %) were C18 : 1ω7c, C17 : 1ω6c, C15 : 0 2-OH and C16 : 0. The genomic DNA G+C content was 59.4 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain 26DY36(T) should be assigned to the genus Altererythrobacter. 16S rRNA gene sequence similarities between the isolate and the type strains of species of the genus Altererythrobacter were in the range 92.7-96.5 %. On the basis of phenotypic and genotypic data, strain 26DY36(T) represents a novel species of the genus Altererythrobacter, for which the name Altererythrobacter atlanticus sp. nov. (type strain, 26DY36(T) = CGMCC 1.12411(T) = JCM 18865(T)) is proposed.

Oceanobacillus neutriphilus sp. nov., isolated from activated sludge in a bioreactor.

A Gram-stain-positive, neutrophilic, rod-shaped bacterium, strain A1g(T), was isolated from activated sludge of a bioreactor and was subjected to a polyphasic taxonomic characterization. The isolate grew in the presence of 0-17.0 % (w/v) NaCl and at pH 6.0-9.0; optimum growth was observed in the presence of 3.0-5.0 % (w/v) NaCl and at pH 7.0. Strain A1g(T) was motile, formed cream-coloured colonies, was catalase- and oxidase-positive and was able to hydrolyse aesculin, Tween 40 and Tween 60. Chemotaxonomic analysis revealed menaquinone-7 as the predominant respiratory quinone and anteiso-C₁₅:₀, anteiso-C₁₇:₀, iso-C₁₆:₀ and iso-C₁₅:₀ as major fatty acids. The genomic DNA G+C content of strain A1g(T) was 36.3 mol%. Comparative 16S rRNA gene sequence analysis revealed that the new isolate belonged to the genus Oceanobacillus and exhibited closest phylogenetic affinity to the type strains of Oceanobacillus oncorhynchi subsp. incaldanensis (97.9 % similarity) and O. oncorhynchi subsp. oncorhynchi (97.5 %), but less than 97 % sequence similarity with respect to the type strains of other recognized Oceanobacillus species. Levels of DNA-DNA relatedness between strain A1g(T) and reference strains O. oncorhynchi subsp. incaldanensis DSM 16557(T), O. oncorhynchi subsp. oncorhynchi JCM 12661(T) and Oceanobacillus iheyensis DSM 14371(T) were 29, 45 and 38 %, respectively. On the basis of phenotypic and genotypic data, strain A1g(T) is considered to represent a novel species of the genus Oceanobacillus, for which the name Oceanobacillus neutriphilus sp. nov. is proposed. The type strain is A1g(T) (=CGMCC 1.7693(T) =JCM 15776(T)).

Halomonas zincidurans sp. nov., a heavy-metal-tolerant bacterium isolated from the deep-sea environment

A Gram-stain-negative, aerobic, rod-like, motile by peritrichous flagella and moderately halophilic bacterium, designated strain B6(T), was isolated a deep-sea sediment collected from the South Atlantic Ocean. The isolate grew with 0.5-15 % (w/v) NaCl, at 4-37 °C and pH 5.0-8.5 and showed a high tolerance to zinc, manganese, cobalt and copper ions. The major fatty acids were C16 : 0, C19 : 0 cyclo ω8c, C12 : 0 3-OH and C12 : 0. The predominant ubiquinone was Q-9. The genomic DNA G+C content was 61.1 mol%. Phylogenetic analysis based on 16S rRNA gene comparisons indicated that strain B6(T) belonged to the genus Halomonas, and the closest relative was Halomonas xinjiangensis TRM 0175(T) (96.1 %). Based upon the phenotypic, chemotaxonomic and genetic data, strain B6(T) represents a novel species from the genus Halomonas, for which the name Halomonas zincidurans sp. nov. is proposed. The type strain is B6(T) ( = CGMCC 1.12450(T) = JCM 18472(T)).

Roseivivax pacificus sp. nov., isolated from deep- sea sediment

A Gram-stain-negative, short-rod-shaped bacterium, designated 22DY03(T), was isolated from a sediment sample collected from the East Pacific Rise. The isolate required NaCl and grew best with 3-7 % (w/v) sea salts at temperature of between 30 and 35 °C at pH 7.0. It formed non-pigmented colonies and produced exopolysaccharide, but did not produce bacteriochlorophyll a. Strain 22DY03(T) was positive for hydrolysis of aesculin and Tween 20 and negative for hydrolysis of casein, DNA, gelatin, starch and Tween 40, 60 and 80. The major respiratory quinone was ubiquinone-10. The polar lipid profile consisted of a mixture of phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol, two unidentified phospholipids and four unidentified polar lipids. The major fatty acids were C19 : 0 cyclo ω8c, C18 : 1ω7c and 11-methyl C18 : 1ω7c. The genomic DNA G+C content was 64.6 mol%. Phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain 22DY03(T) should be assigned to the genus Roseivivax. The 16S rRNA gene sequence similarities between the isolate and the type strains of species of the genus Roseivivax were in the range of 94.1-95.8 %. On the basis of phenotypic and genotypic data, it is concluded that strain 22DY03(T) represents a novel species of the genus Roseivivax, for which the name Roseivivax pacificus sp. nov. (type strain 22DY03(T) = CGMCC 1.12410(T) = JCM 18866(T)) is proposed.

Kordiimonas lipolytica sp. nov., isolated from seawater.

A Gram-stain-negative, aerobic, rod-shaped bacterium, designated M41T, was isolated from a surface seawater sample collected from the western Pacific Ocean. The isolate grew in medium containing 0.5-10.0 % (w/v) NaCl (optimally at 1.0-3.0 %) at 15-45 °C and pH 5.5-9.5. Positive for oxidase, catalase and nitrate reduction. The respiratory quinone is Q-10. The major fatty acids (>10 %) are iso-C15:0, iso-C17:1ω9c and summed feature 3 (comprising C16:1ω7c and/or iso-C15:0 2-OH). The major polar lipids are phosphatidylethanolamine, one unidentified phospholipid, one unidentified aminolipid, and three unidentified glycolipids.The genomic DNA G+C content is 56.3 mol %. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M41T should be assigned to the genus Kordiimonas. The 16S rRNA gene sequence similarities between the isolate and the type strains of species of the genus Kordiimonas with validly published names were in the range 96.2- 98.6 %. Strain M41T exhibited average nucleotide identity (ANI) values of 81.7 and 72.3 % with respect to Kordiimonas. lacus S3-22T and Kordiimonasgwangyangensis JCM 12864T, respectively. The genome-to-genome distance analysis revealed that strain M41T shared 51.4 % DNA-DNA relatedness with K. lacus S3-22T and 16.3 % with K. gwangyangensis JCM 12864T. On the basis of phenotypic and genotypic characteristics, strain M41T represents a novel species of the genus Kordiimonas, for which the name Kordiimonas lipolytica sp. nov. is proposed. The type strain is M41T (=CGMCC 1.15304T=JCM 30877T). An emended description of Kordiimonas lacus is also provided.

Marinirhabdus gelatinilytica gen. nov., sp. nov., isolated from seawater.

A Gram-stain-negative, aerobic and slightly halophilic bacterium was isolated from the South China Sea, and was subjected to characterization using a polyphasic taxonomic approach. Cells of the isolate, designated NH83T, were non-motile and rod-shaped. On the basis of 16S rRNA gene sequence analysis, strain NH83Twas closely related to members of the genera Aureisphaera (with sequence similarity of 92.9 %), Jejudonia (92.8 %), Marixanthomonas (92.6 %), Altuibacter (92.6 %), Ulvibacter (91.5-91.9 %), Gilvibacter (91.8 %) and Aequorivita (89.6-91.2 %), all of which belong to the family Flavobacteriaceae. Phylogenetic analysis indicated that it represented an independent lineage and its closest relatives belonged to the genus Marixanthomonas. The sole respiratory quinone was MK-6. The major polar lipids were phosphatidylethanolamine, two aminolipids, one aminophospholipid and one unidentified lipid. The principal fatty acids were branched fatty acids, including iso-C15 : 0, iso-C17 : 0 3-OH, iso-C16 : 0, iso-C15 : 1 G and summed feature 3 (iso-C15 : 0 2-OH and/or C16 : 1ω7c). The genomic DNA G+C content was 41.0 mol%. Strain NH83T was positive for hydrolysis of aesculin, gelatin and Tween 60. Phylogenetic distinctiveness and chemotaxonomic differences, together with differential phenotypic properties, revealed that strain NH83T could be differentiated from closely related genera. Therefore, it is proposed that strain NH83T represents a novel species in a new genus, for which the name Marinirhabdus gelatinilytica gen. nov., sp. nov. (type strain NH83T=CGMCC 1.15462T=DSM 101478T) is proposed.

Investigation of mercury tolerance in Chromohalobacter israelensis DSM 6768T and Halomonas zincidurans B6T by comparative genomics with Halomonas xinjiangensis TRM 0175T.

Chromohalobacter israelensis DSM 6768(T), Halomonas zincidurans B6(T), and Halomonas xinjiangensis TRM 0175(T) are three phylogenetically close strains belonging to the class Gammaproteobacteria. Both strains DSM 6768(T) and B6(T) can grow on plate containing 0.5mM HgCl2. Strain TRM 0175(T) could not grow on plates containing 0.1mM or more HgCl2. Here we report the draft genomes of strains DSM 6768(T) and TRM 0175(T) for comparative genomic analysis. Gene cluster with putative function in mercury resistance in strain DSM 6768(T) includes a mercuric ion reductase, whose homologues distribute among several marine microbes. Strain B6(T), which was isolated from the Atlantic Ocean, has one more gene cluster with putative function in mercury resistance than strain DSM 6768(T). This study will enhance our understanding of the mercury tolerance and further investigation in marine microbes.

Pseudoalteromonas gelatinilytica sp. nov., isolated from surface seawater.

Three Gram-stain-negative, rod-shaped bacteria, designated strains NH153T, F-2-11 and M-1-78, were isolated from surface seawater of the South China Sea and the East China Sea. The three isolates were able to grow at 15-45 °C (optimum 28-37 °C), but no growth occurred at 4 or 50 °C. The pH range for growth was pH 5.5-9.5 (optimum pH 7.5-8.5). The isolates required sea salts for growth and growth occurred in the presence of 0-10 % (w/v) NaCl (optimum 3-5 %); no growth occurred in the presence of 12.0, 15.0 or 20.0 % (w/v) NaCl. They were positive for hydrolysis of gelatin and Tween 80. The sole respiratory quinone was ubiquinone-8 (Q-8). The major cellular fatty acids (>10 %) were C16 : 0, C18 : 1ω7c and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH). The major polar lipid components were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified glycolipid, one unidentified phospholipid and one unidentified lipid. The genomic DNA G+C content of strain NH153T was 41.4 mol%. Based on 16S rRNA gene sequence analysis, the isolates were closely related to the type strain of Pseudoalteromonas shioyasakiensis (98.0-98.6 % sequence similarity). The 16S rRNA gene sequence similarities between the three isolates were 98.8-99.7 %. Phylogenetic analysis indicated that they formed a distinct lineage and clustered with P. shioyasakiensis and Pseudoalteromonas arabiensis. The level of DNA-DNA relatedness among the three isolates was 78.0-85.5 %. Strain NH153T exhibited average nucleotide identity values of 93.4 and 84.2 % with respect to P. shioyasakiensisJCM 18891T and P. arabiensisJCM 17292T, respectively. The genome-to-genome distance analysis revealed that strain NH153T shared 52.4 % DNA relatedness with P. shioyasakiensisJCM 18891T and 28.1 % with P. arabiensisJCM 17292T. On the basis of the phenotypic, genotypic and chemotaxonomic characterizations, as well as phylogenetic inference obtained in this study, strains NH153T, F-2-11 and M-1-78 represent a novel species within the genus Pseudoalteromonas, for which the name Pseudoalteromonasgelatinilytica sp. nov. is proposed. The type strain is NH153T (=CGMCC 1.15370T=DSM 100951T), and F-2-11 (=CGMCC 1.15364=DSM 100953) and M-1-78 (=CGMCC 1.15365=DSM 100952), are additional strains of the species.

Marinobacter fuscus sp. nov., a marine bacterium of Gammaproteobacteria isolated from surface seawater

A Gram-stain-negative bacterium, designated NH169-3T, was isolated from a surface seawater sample of the South China Sea and subjected to a taxonomic polyphasic investigation. Strain NH169-3T was strictly aerobic, non-motile, non-spore-forming and rod-shaped. The colony was 1.0-2.0 mm in diameter after the growth on marine agar at 30 °C for 72 h. The centre of the colony was smooth, circular, convex and brown with a transparent periphery. Strain NH169-3T was able to grow at temperatures between 4-40 °C (optimum, 37 °C), pH 5.5-9.0 (pH 7.5) and with 0-12.5 % (w/v) NaCl (3.0 %). Chemotaxonomic analysis showed that the sole respiratory quinone of strain NH169-3T was ubiquinone 9; major fatty acids were C16 : 0 and C18 : 1ω9c, and major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol and one unidentified glycolipid. The DNA G+C content was 52.7 mol%. The comparison of 16S rRNA gene sequences showed that strain NH169-3T was closely related to Marinobacter shengliensis SL013A34A2T with a similarity of 98.0 %. Three phylogenetic trees reconstructed with neighbour-joining, maximum-parsimony and maximum-likelihood methods using 16S rRNA gene sequences showed that strain NH169-3T was grouped into a separated branch with M. shengliensis SL013A34A2T in a clade of the genus Marinobacter and closely related to Marinobacter halophilus JCM 30472T, Marinobacter vinifirmus DSM 17747T and Marinobacter hydrocarbonoclasticus DSM 8798T. Analyses of both phenotypic and phylogenetic properties have suggested that strain NH169-3T was distinctive from species with validly published names in genus Marinobacter. Thus, strain NH169-3T (=MCCC 1K03455T=KCTC 62226T) is proposed as a novel species in genus Marinobacter with the name Marinobacter fuscus sp. nov.