Ang Liu

Marinobacter antarcticus sp. nov., a halotolerant bacterium isolated from Antarctic intertidal sandy sediment.

A Gram-staining-negative, aerobic, motile, oxidase- and catalase-positive, rod-shaped strain, designated ZS2-30(T), was isolated from Antarctic intertidal sandy sediment. The strain grew at 4-35 °C (optimum, 25 °C) and in 0-25% (w/v) NaCl (optimum, 3.0-4.0%). It could reduce nitrate to nitrite and hydrolyse Tween 80. The predominant cellular fatty acids of strain ZS2-30(T) were summed feature 3 (C(16:1)ω7c and/or C(16:1)ω6c), C(16:0), C(18:1)ω9c, C(16:1)ω9c, C(12:0) 3-OH and C(12:0). The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol and an unidentified aminophospholipid. The genomic DNA G+C content of strain ZS2-30(T) was 55.8 mol%. Analyses of 16S rRNA gene sequences revealed that strain ZS2-30(T) was affiliated with the genus Marinobacter. It showed highest 16S rRNA gene sequence similarities to the type strains of three species of the genus Marinobacter, namely Marinobacter maritimus (98.3%), Marinobacter psychrophilus (98.1%) and Marinobacter goseongensis (97.1%), but the DNA-DNA relatedness values between strain ZS2-30(T) and the above three species were all lower than 45%. Moreover, strain ZS2-30(T) could be distinguished from closely related species of the genus Marinobacter by various phenotypic properties. Based on this taxonomic study using a polyphasic approach, strain ZS2-30(T) is considered to represent a novel species in the genus Marinobacter, for which the name Marinobacter antarcticus sp. nov. is proposed. The type strain of Marinobacter antarcticus is ZS2-30(T) ( = CGMCC 1.10835(T) = KCTC 23684(T)).

Neptunomonas qingdaonensis sp. nov., isolated from intertidal sand

A Gram-negative, motile, aerobic, oxidase- and catalase-positive rod, designated P10-2-4(T), was isolated from an intertidal sand sample collected from a coastal area of Qingdao (Yellow Sea), China. The isolate reduced nitrate to nitrite and grew at 4-33 °C and with 0.5-12 % (w/v) NaCl. The predominant cellular fatty acids were summed feature 3 (C16 : 1ω7c and/or iso-C15 : 0 2-OH), C18 : 1ω7c and C16 : 0. The major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The major respiratory quinone was Q-8. The genomic DNA G+C content was 45.1 %. Phylogenetic analysis of 16S rRNA gene sequences revealed that strain P10-2-4(T) belonged to the genus Neptunomonas. The isolate shared the highest 16S rRNA gene sequence similarity (98.1 %) with Neptunomonas japonica JAMM 0745(T) and 96.9, 96.5 and 95.9 % sequence similarities with N. antarctica S3-22(T), N. concharum LHW37(T) and N. naphthovorans NAG-2N-126(T), respectively, strains of the other three recognized species in the genus. DNA-DNA relatedness between strain P10-2-4(T) and N. japonica JCM 14595(T) was 35.6 %. Furthermore, strain P10-2-4(T) could be distinguished from the representatives of the genus Neptunomonas by a combination of phenotypic characteristics, such as temperature and NaCl concentration for growth, nitrate reduction, DNase activity and assimilation of substrates. The data from this study suggests that strain P10-2-4(T) represents a novel species in the genus Neptunomonas, for which the name Neptunomonas qingdaonensis sp. nov. is proposed. The type strain is P10-2-4(T) ( = CGMCC 1.10971(T)  = KCTC 23686(T)).

Marinicauda pacifica gen. nov., sp. nov., a prosthecate alphaproteobacterium of the family Hyphomonadaceae isolated from deep seawater

A marine prosthecate bacterium, designated strain P-1 km-3(T), was isolated from deep seawater from the Pacific. Cells of strain P-1 km-3(T) were Gram-stain-negative, aerobic, catalase- and oxidase-positive, dimorphic rods with a single polar prostheca or flagellum. The strain hydrolysed gelatin and grew at 6-40 °C (optimum, 30 °C) and with 0.5-12% (w/v) NaCl (optimum, 2%). Phylogenetic analysis of the 16S rRNA gene sequences revealed that strain P-1 km-3(T) belonged to the family Hyphomonadaceae in the class Alphaproteobacteria and represented a separate lineage, located between the genera Oceanicaulis and Woodsholea. Sequence similarities of strain P-1 km-3(T) with type strains of species of the genera Oceanicaulis and Woodsholea were 93.2-93.9%. The predominant cellular fatty acids in strain P-1 km-3(T) were C18:1ω7c, C18:0, 11-methyl C18:1ω7c, C17:0 and C19:0 cyclo ω8c. The major respiratory quinone of strain P-1 km-3(T) was Q-10. The polar lipids of strain P-1 km-3(T) comprised glucuronopyranosyldiglyceride (GUDG), monoglycosyldiglyceride (MGDG), sulfo-quinovosyl diacylglycerol (SQDG), phosphatidylglycerol (PG), an unidentified phospholipid (PL) and an unidentified lipid (L). The genomic DNA G+C content of strain P-1 km-3(T) was 66.0 mol%. On the basis of the polyphasic data presented in this study, strain P-1 km-3(T) is proposed to represent a novel species in a new genus, Marinicauda pacifica gen. nov., sp. nov., within the family Hyphomonadaceae. The type strain of the type species is P-1 km-3(T) (=KACC 16526(T)=CGMCC 1.11031(T)).

Pseudorhodobacter antarcticus sp. nov., isolated from Antarctic intertidal sandy sediment, and emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012.

A Gram-negative, aerobic, non-motile, pink-pigmented and rod-shaped strain, designated ZS3-33(T), was isolated from Antarctic intertidal sandy sediment. The strain grew optimally at 15 °C and with 1.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed Tween 20. It could not produce bacteriochlorophyll a. The predominant cellular fatty acid was C18 : 1ω7c and the predominant respiratory quinone was Q-10. The major polar lipids were phosphatidylglycerol, phosphatidylcholine, two unidentified aminophospholipids and an unidentified aminolipid. Analyses of 16S rRNA gene sequences revealed that strain ZS3-33(T) belonged to the genus Pseudorhodobacter, showing 97.4 % similarity to the type strain of Pseudorhodobacter ferrugineus and 95.3 % similarity to the type strain of Pseudorhodobacter aquimaris. Levels of gyrB gene sequence similarity between strain ZS3-33(T) and the type strains of P. ferrugineus and P. aquimaris were 87.6 and 81.7 %, respectively. DNA-DNA relatedness between strain ZS3-33(T) and P. ferrugineus DSM 5888(T) was 56.6 %. The genomic DNA G+C content of strain ZS3-33(T) was 57.1 mol%. Based on data from this polyphasic study, strain ZS3-33(T) represents a novel species of the genus Pseudorhodobacter, for which the name Pseudorhodobacter antarcticus sp. nov. is proposed. The type strain is ZS3-33(T) ( = CGMCC 1.10836(T) = KCTC 23700(T)). An emended description of the genus Pseudorhodobacter Uchino et al. 2002 emend. Jung et al. 2012 is also proposed.

Marivirga atlantica sp. nov., isolated from seawater and emended description of the genus Marivirga.

A novel Gram-stain-negative, aerobic, orange-pigmented, non-flagellated, gliding, rod-shaped bacterium, designated strain SM1354(T) was isolated from surface seawater of the Atlantic Ocean. The strain hydrolysed gelatin and DNA but did not reduce nitrate. It grew at 4-40 °C and with 0.5-11% (w/v) NaCl. Phylogenetic analysis of the 16S rRNA gene sequences revealed that strain SM1354(T) belonged to the genus Marivirga with 96.0-96.2% sequence similarities to known species of the genus Marivirga . The major fatty acids of strain SM1354(T) were iso-C15 : 0, iso-C15 : 1 G, iso-C17 : 03-OH and summed feature 3 (C16 : 1ω7c and/or iso-C15 : 02-OH). Polar lipids of strain SM1354(T) included phosphatidylethanolamine, three unidentified lipids and one unidentified aminolipid and aminophospholipid. The major respiratory quinone of strain SM1354(T) was menaquinone 7 (MK-7). The genomic DNA G+C content of strain SM1354(T) was 33.9 ± 0.4 mol%. On the basis of the results of the polyphasic characterization in this study, it is proposed that strain SM1354(T) represents a novel species of the genus Marivirga , namely Marivirga atlantica sp. nov. The type strain of Marivirga atlantica is SM1354(T) ( =CCTCC AB 2014242(T) =JCM 30305(T)). An emended description of the genus Marivirga is also proposed.

Bizionia arctica sp. nov., isolated from Arctic fjord seawater, and emended description of the genus Bizionia.

A Gram-stain-negative, yellow-pigmented, aerobic, non-flagellated, non-gliding bacterial strain, designated SM1203(T), was isolated from surface seawater of Kongsfjorden, Svalbard. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain SM1203(T) was affiliated with the genus Bizionia in the family Flavobacteriaceae. The strain shared the highest 16S rRNA gene sequence similarity (>96%) with the type strains of Formosa spongicola (96.8%), Bizionia paragorgiae (96.3%), B. saleffrena (96.3%) and B. echini (96.1%) and 95.4-95.7% sequence similarity with the type strains of other known species of the genus Bizionia. The strain grew at 4-30 °C and in the presence of 1.0-5.0% (w/v) NaCl. The major fatty acids of strain SM1203(T) were iso-C15 : 0, iso-C15 : 1, anteiso-C15 : 0 and C15 : 0 and the main polar lipids were phosphatidylethanolamine and an unidentified lipid. The major respiratory quinone of strain SM1203(T) was menaquinone 6 (MK-6). The genomic DNA G+C content of strain SM1203(T) was 34.8 mol%. Based on the polyphasic characterization of strain SM1203(T) in this study, the strain represents a novel species in the genus Bizionia, for which the name Bizionia arctica sp. nov. is proposed. The type strain is SM1203(T) ( = CGMCC 1.12751(T) = JCM 30333(T)). An emended description of the genus Bizionia is also given.

Exopolysaccharides Play a Role in the Swarming of the Benthic Bacterium Pseudoalteromonas sp. SM9913

Most marine bacteria secrete exopolysaccharide (EPS), which is important for bacterial survival in the marine environment. However, it is still unclear whether the self-secreted EPS is involved in marine bacterial motility. Here we studied the role of EPS in the lateral flagella-driven swarming motility of benthic bacterium Pseudoalteromonas sp. SM9913 (SM9913) by a comparison of wild SM9913 and ΔepsT, an EPS synthesis defective mutant. Reduction of EPS production in ΔepsT did not affect the growth rate or the swimming motility, but significantly decreased the swarming motility on a swarming plate, suggesting that the EPS may play a role in SM9913 swarming. However, the expression and assembly of lateral flagella in ΔepsT were not affected. Instead, ΔepsT had a different swarming behavior from wild SM9913. The swarming of ΔepsT did not have an obvious rapid swarming period, and its rate became much lower than that of wild SM9913 after 35 h incubation. An addition of surfactin or SM9913 EPS on the surface of the swarming plate could rescue the swarming level. These results indicate that the self-secreted EPS is required for the swarming of SM9913. This study widens our understanding of the function of the EPS of benthic bacteria.

Arenitalea lutea gen. nov., sp. nov., a marine bacterium of the family Flavobacteriaceae isolated from intertidal sand.

A yellow, rod-shaped, Gram-negative, facultatively aerobic, gliding bacterium, designed strain P7-3-5(T), was isolated from intertidal sand of the Yellow Sea, China. Analysis of 16S rRNA gene sequences revealed that strain P7-3-5(T) formed a distinct lineage within the family Flavobacteriaceae, sharing 94.2-96.9 % sequence similarity with type strains of species of the most closely related genera, including Hyunsoonleella, Jejuia, Marinivirga and Algibacter. The strain grew at 4-40 °C and with 0.5-5.0 % (w/v) NaCl. It reduced nitrate to nitrite and hydrolysed gelatin and DNA. The major cellular fatty acids were iso-C15 : 0, iso-C15 : 1 G and anteiso-C15 : 0 and the major respiratory quinone was MK-6. Polar lipids included phosphatidylethanolamine (PE), three unidentified aminolipids (AL1-3) and four unidentified lipids (L1-4). The genomic DNA G+C content of strain P7-3-5(T) was 32.1 mol%. Data from this polyphasic study suggest that strain P7-3-5(T) represents a novel species in a new genus in the family Flavobacteriaceae, for which the name Arenitalea lutea gen. nov., sp. nov. is proposed. The type strain of Arenitalea lutea is P7-3-5(T) ( = CGMCC 1.12213(T) = KACC 16457(T)).

Albimonas pacifica sp. nov., isolated from seawater of the Pacific, and emended description of the genus Albimonas.

A Gram-stain-negative, aerobic, catalase- and oxidase-positive, non-flagellated, rod-shaped bacterium, designated strain P-50-3(T), was isolated from seawater of the Pacific. The strain grew at 10-40 °C (optimum at 30 °C) and with 0-12 % (w/v, optimum 2 %) NaCl. It reduced nitrate to nitrite but did not hydrolyse gelatin, starch or Tween 80. Analysis of 16S rRNA gene sequences showed that strain P-50-3(T) clustered tightly with the genus Albimonas and shared the highest 16S rRNA gene sequence similarity (94.3 %) with the type strain of Albimonas donghaensis. The major respiratory quinone was Q-10 and the major cellular fatty acids were C18 : 1ω7c, C18 : 0, 11-methyl C18 : 1ω7c and C16 : 0. Polar lipids included phosphatidylglycerol (PG), phosphatidylcholine (PC), two unidentified aminolipids and an unidentified lipid. The genomic DNA G+C content of strain P-50-3(T) was 69.0 mol%. On the basis of the data obtained in this polyphasic study, strain P-50-3(T) represents a novel species within the genus Albimonas, for which the name Albimonas pacifica sp. nov. is proposed. The type strain of Albimonas pacifica is P-50-3(T) ( = KACC 16527(T) = CGMCC 1.11030(T)). An emended description of the genus Albimonas Lim et al. 2008 is also proposed.

Haliea atlantica sp. nov., isolated from seawater, transfer of Haliea mediterranea to Parahaliea gen. nov. as Parahaliea mediterranea comb. nov. and emended description of the genus Haliea

A novel Gram-stain-negative, oxidase- and catalase-positive, aerobic bacterium, designated strain SM1351T, was isolated from surface seawater of the Atlantic Ocean. This strain grew at 4-45 °C and with 5-90 g NaCl l- 1. It did not reduce nitrate to nitrite and could not hydrolyse starch or DNA. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain was affiliated with the genus Haliea in the family Alteromonadaceae, with sequence similarities with the type strains of Haliea salexigens and Haliea mediterranea, the two recognized species of the genus Haliea, of 96.2 and 94.6 %, respectively. The major fatty acids of strain SM1351T were C16 : 1ω7c and/or iso-C15 : 0 2-OH, C17 : 1ω8c, C18 : 1ω7c and C16 : 0 and the major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. The major respiratory quinone was ubiquinone Q-8. The genomic DNA G+C content of strain SM1351T was 62 mol%. On the basis of the polyphasic characterization of strain SM1351T in this study, it is considered to represent a novel species in the genus Haliea, for which the name Haliea atlantica sp. nov. is proposed. The type strain is SM1351T ( = CCTCC AB 2014266T = JCM 30304T). Moreover, the transfer of Haliea mediterraneaLucena et al. 2010 to Parahaliea gen. nov. as Parahaliea mediterranea comb. nov. (type strain 7SM29T = CECT 7447T = DSM 21924T) and an emended description of the genus Haliea are also proposed.