Yan-Xia Zhou

Aquimarina agarivorans sp. nov., a genome-sequenced member of the class Flavobacteriia isolated from Gelidium amansii.

A novel Gram-stain-negative, facultatively anaerobic, rod-shaped, agar-digesting bacterial strain, designated HQM9T, was isolated from the surface of the marine red alga Gelidium amansii collected from the intertidal zone of Weihai, China. Cells of HQM9T were 3.0-4.0 μm long and 0.2-0.3 μm wide and lacked flagella. The new isolate grew optimally at 28-30 °C, at pH 7.0-7.5, and in the presence of 2.5-3.0% NaCl. The predominant cellular fatty acids were iso-C15 : 0 and iso-C17 : 0 3-OH. The sole menaquinone was MK-6. The DNA G+C content was 33 mol%. The major polar lipids were comprised of phosphatidylethanolamine and four unknown polar lipids. Based on the 16S rRNA gene sequence, the closest relative was Aquimarina agarilytica ZC1T with 97.16% sequence similarity, with which strain HQM9T formed a distinct cluster belonging to the genus Aquimarina in a phylogenetic tree. Moreover, average nucleotide identity and estimated DNA-DNA hybridization values between strains HQM9T and ZC1T were 78.7% and 12.50 ± 2.95%, respectively. On the basis of phenotypic, chemotaxonomic and phylogenetic analysis, strain HQM9T represents the type strain of a novel species within the genus Aquimarina in the family Flavobacteriaceae, phylum Bacteroidetes, for which the name Aquimarina agarivorans sp. nov. is proposed. The type strain is HQM9T ( = ATCC BAA-2612T = CICC 10835T).

Longimonas halophila gen. nov., sp. nov., isolated from a marine solar saltern.

A bacterial strain, designated SYD6(T), was isolated from a marine solar saltern on the coast of Weihai, Shandong Province, PR China. Cells of strain SYD6(T) were rod-shaped, red, and approximately 5.0-9.0 μm in length and 0.4-0.6 μm in width. The strain was Gram-stain-negative, facultatively anaerobic, heterotrophic, catalase-positive and oxidase-negative. Growth occurred in 4-25% (w/v) NaCl [with 2-15% (w/v) MgCl2.6H2O also present], at 20-50 °C and pH 6.5-8.5. Optimal growth was observed at 37-42 °C, pH 7.5-8.0, with 6-8% (w/v) NaCl [with 2-4% (w/v) MgCl2.6H2O]. Nitrate was not reduced. Glucose, sucrose, maltose, fructose and ribose stimulated growth, but not glycerol, xylose or mannitol. The G+C content of the genomic DNA was 61.5 mol% (HPLC). The sole methyl naphthoquinone was MK-7 and the predominant cellular fatty acids (>10%) were iso-C15 : 0 2-OH/C16 : 1ω7c, iso-C16 : 0, C18 : 1ω7c/C18 : 1ω6c and C18 : 1ω7c. The predominant polar lipids were phosphatidylethanolamine, phosphatidylcholine, diphosphatidylglycerol and an unknown lipid. Phylogenetic analysis, based on 16S rRNA gene sequences, demonstrated that strain SYD6(T) was affiliated with the phylum Bacteroidetes. The most closely related neighbours were species of the genus Salisaeta and strain SYD6(T) had a 16S rRNA gene sequence similarity of 91.97% with Salisaeta longa DSM 21114(T). On the basis of these phenotypic and phylogenetic data, strain SYD6(T) represents a novel species of a new genus of the family Rhodothermaceae, for which the name Longimonas halophila gen. nov., sp. nov. is proposed. The type strain of the type species is SYD6(T) ( = CICC 10838(T) = KCTC 42399(T)).

Carboxylicivirga linearis sp. nov., isolated from a sea cucumber culture pond.

A yellow-pigmented, Gram-stain-negative and facultatively anaerobic bacterium, designated FB218T, was isolated from a sediment sample collected from a sea cucumber culture pond in Rongcheng, China (36° 54′ 36″ N 122° 14′ 34″ E). Cells of strain FB218T were slender, gliding, catalase-positive and oxidase-negative. Optimal growth occurred at 30 °C, pH 6.5–7.0 and in medium containing 2–3 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain FB218T belonged to the genus Carboxylicivirga, family Marinilabiliaceae. The predominant fatty acids were iso-C15 : 0 and anteiso-C15 : 0. MK-7 was the main respiratory quinone. The major polar lipids of strain FB218T were two unidentified lipids and a phospholipid. The genomic DNA G+C content was 40.0 mol%. Based on the distinct phylogenetic position and the combination of physiological and phenotypic characteristics, strain FB218T represents a novel species of the genus Carboxylicivirga, for which the name Carboxylicivirga linearis sp. nov. is proposed. The type strain is FB218T ( = KCTC 42254T = MCCC 1H00106T). An emended description of the genus Carboxylicivirga is also provided.

Seonamhaeicola algicola sp. nov., a complex-polysaccharide-degrading bacterium isolated from Gracilaria blodgettii, and emended description of the genus Seonamhaeicola

A novel Gram-stain-negative, yellow, rod-shaped, facultatively anaerobic, gliding bacterial strain, designated Gy8T, was isolated from the surface of Gracilaria blodgettii. This bacterium was able to degrade various polysaccharides, especially agar and alginate. The major cellular fatty acids (>10 % of the total fatty acids) were C15 : 0, iso-C15 : 0, C15 : 0 3-OH and iso-C15 : 1. The major menaquinone was MK-6. The DNA G+C content was 35.3 mol%. The major polar lipids consisted of phosphatidylethanolamine and two unknown polar lipids. Strain Gy8T showed highest 16S rRNA gene sequence similarity to Seonamhaeicola aphaedonensis AH-M5T (95.6 %), and these two strains formed a distinct branch in phylogenetic trees generated with the neighbour-joining, maximum-likelihood and maximum-parsimony algorithms. The novel strain and the reference type strain of the single species described to date in the genus Seonamhaeicola contained MK-6 as the major menaquinone, iso-C15 : 0 and iso-C15 : 1 as the major fatty acids, and phosphatidylethanolamine and an unknown lipid as the major polar lipids. Based on phenotypic, chemotaxonomic and phylogenetic analysis, strain Gy8T is considered to represent a novel species within the genus Seonamhaeicola in the family Flavobacteriaceae, phylum Bacteroidetes, for which the name Seonamhaeicola algicola sp. nov. is proposed. The type strain is Gy8T ( = KCTC 42396T = CICC 23816T).

Alkalimarinus sediminis gen. nov., sp. nov., isolated from marine sediment.

Strain FA028T, a beige-pigmented, facultatively anaerobic, heterotrophic, catalase-negative and oxidase-positive, Gram-stain-negative bacterium, was isolated from marine sediment of the coast of Weihai, China. Cells of strain FA028T were rod-shaped, 1–3 μm in length and 0.5 μm in width. The strain was able to grow at 13–37 °C, at pH 7.0–9.5 and in the presence of 1.0–4.0 % (w/v) NaCl. Optimal growth was observed at 28 °C, with 3.0 % NaCl and at pH 7.5–8.0. Nitrate was not reduced. The G+C content of the DNA was 43.4 mol%. The isoprenoid quinone was Q-9 and the main cellular fatty acids (>10 %) were C16 : 0, C16 : 1ω9c and iso-C15 : 0 2-OH/C16 : 1ω7c. The major polar lipids in strain FA028T were phosphatidylglycerol, phosphatidylethanolamine and diphosphatidylglycerol; phospholipid was present in moderate to minor amounts in the polar lipid profile. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain FA028T was affiliated with the phylum Proteobacteria. 16S rRNA gene sequence comparisons showed that this isolate is unique, sharing < 93 % similarity with species of the families Alteromonadaceae and Oceanospirillaceae. On the basis of the phenotypic and phylogenetic data, strain FA028T should be classified as representing a novel species of a new genus within the family Alteromonadaceae, for which the name Alkalimarinus sediminis gen. nov., sp. nov. is proposed. The type strain of Alkalimarinus sediminis is FA028T ( = CICC 10906T = KCTC 42258T).