Modern studies on marine airborne prokaryotes over open seas have been rare. Here, to understand their distribution and composition, aerosol as well

A slightly curved, rod-shaped marine bacterium, designated strain CL-S1^T, was isolated from near Dokdo, an island in the East Sea, Korea. Cells were Gram-negative and grew well under either aerobic or microaerobic conditions. Analyses of the 16S rRNA and gyrA gene sequences of strain CL-S1^T revealed an affiliation with the genus Arcobacter within the class Epsilonproteobacteria. Phylogenetic analyses based on 16S rRNA and gyrA gene sequences showed that strain CL-S1^T formed a robust clade with Arcobacter halophilus LA31B^T, with sequence similarities of 96.1 and 88.2 %, respectively. DNA–DNA relatedness between strain CL-S1^T and A. halophilus DSM 18005^T was 44 %, indicating that they represent genomically distinct species. Strain CL-S1^T grew optimally at 30–37 °C, at pH 7 and in the presence of 3–5 % NaCl. The dominant cellular fatty acids were iso-C_15 : 0 2-OH and/or C_16 : 1 ω7c (28.4 %), C_16 : 0 (26.2 %) and C_18 : 1 ω7c (22.3 %). The DNA G+C content of strain CL-S1^T was 28 mol%. Strain CL-S1^T differed phenotypically from A. halophilus LA31B^T based on its ability to grow aerobically at 10 °C and inability to grow under anaerobic conditions. Based on the data presented, strain CL-S1^T is considered to represent a novel species of the genus Arcobacter, for which the name Arcobacter marinus sp. nov. is proposed. The type strain is CL-S1^T (=KCCM 90072^T =JCM 15502^T).

A Gram-negative, pink-coloured, rod-shaped, non-flagellated bacterium, designated CL-GP80^T, was isolated from a hypertrophic pond located within the campus of Seoul National University, Korea. Analysis of its 16S rRNA gene sequence revealed that strain CL-GP80^T belongs to the family Sphingobacteriaceae and is closely related to Pedobacter heparinus ATCC 13125^T (95.8 % sequence similarity) and to other members of the genus Pedobacter (90.8–95.3 % similarity). Temperature and pH ranges for growth were 5–33 °C and pH 6–8, respectively. The DNA G+C content was 41.3 mol%. The major fatty acids were iso-C_15 : 0 (37.0 %), iso-C_15 : 0 2-OH and/or C_16 : 1 ω7c (24.5 %), and iso-C_17 : 0 3-OH (11.3 %). Phenotypic, chemotaxonomic and phylogenetic analyses indicated that strain CL-GP80^T could be assigned to the genus Pedobacter, but distinguished from recognized species of the genus. Strain CL-GP80^T (=KCCM 42272^T=JCM 13399^T) is therefore proposed as the type strain of a novel species, for which the name Pedobacter roseus sp. nov. is proposed.

A halotolerant, facultatively alkaliphilic bacterium, designated CL-MP28^T, was isolated from the surface of a sediment core sample collected at a depth of 2247 m in the Ulleung Basin of the East Sea, Korea. Phylogenetic analysis of the 16S rRNA gene sequence of strain CL-MP28^T revealed an affiliation with the genus Oceanobacillus. The sequence similarities between the isolate and type strains of members of the genus Oceanobacillus were in the range 95.0–96.0 %, indicating that strain CL-MP28^T represented a novel species within the genus. The strain was found to be Gram-positive, rod-shaped and motile by means of peritrichous flagella and was shown to produce ellipsoidal spores. The strain was strictly aerobic and able to grow with NaCl at concentrations in the range 0–14 % (w/v) at pH 7.5. The strain grew at temperatures of 15–42 °C and at pH 6.5–9.5. The major fatty acids were anteiso-C_15 : 0 (64.9 %), anteiso-C_17 : 0 (11.9 %) and iso-C_16 : 0 (7.7 %). The major isoprenoid quinone was MK-7. The DNA G+C content was 40.2 mol%. According to the 16S rRNA gene sequence, DNA–DNA relatedness and physiological data and the fatty acid composition, CL-MP28^T could be assigned to the genus Oceanobacillus, but is distinguishable from the recognized species of this genus. Strain CL-MP28^T therefore represents a novel species within the genus Oceanobacillus, for which the name Oceanobacillus profundus sp. nov. is proposed. The type strain is CL-MP28^T (=KCCM 42318^T=DSM 18246^T).

A Gram-staining-negative, rod-shaped and non-motile bacterium, designated CL-SS4T, was isolated from crude-oil-contaminated seawater from the west coast of Korea and was investigated by means of a polyphasic taxonomic approach. Strain CL-SS4T grew optimally at 25–30 °C, at pH 6.8–7.7 and in the presence of 2–3 % sea salts. The major fatty acids were iso-C17 : 0 3-OH, iso-C15 : 0 and iso-C15 : 1 G. The major isoprenoid quinone was MK-6. The DNA G+C content was 50.7 mol%. Analysis of the 16S rRNA gene sequence of strain CL-SS4T revealed that it was a member of the genus Muricauda, sharing 95.7–96.9 % sequence similarity with the type strains of Muricauda species and being most closely related to Muricauda aquimarina SW-63T. Phylogenetic analyses based on 16S rRNA gene sequences confirmed that strain CL-SS4T formed a deep lineage related to the genus Muricauda. Strain CL-SS4T was distinguishable from recognized Muricauda species on the basis of differential phenotypic characteristics and DNA G+C content. Based on these results, it is proposed that strain CL-SS4T represents a novel species of the genus Muricauda, for which the name Muricauda olearia sp. nov. is proposed. An emended description of the genus Muricauda is also proposed. The type strain is CL-SS4T (=KCCM 90075T=JCM 15563T).

A rod-shaped marine bacterium, designated strain CL-TF09^T, isolated from a tidal flat in Ganghwa, Korea, was characterized based on its physiological and biochemical features, fatty acid profile and phylogenetic position. 16S rRNA gene sequence analysis revealed a clear affiliation with the family Flavobacteriaceae. Strain CL-TF09^T showed the closest phylogenetic relationship with the genera Tenacibaculum and Polaribacter; sequence similarities between CL-TF09^T and the type strains of Tenacibaculum and Polaribacter species ranged from 90·7 to 91·8 %. Cells of strain CL-TF09^T were non-motile and grew on solid media as yellow colonies. The strain grew in the presence of 1–5 % sea salts, within a temperature range of 5–30 °C and at pH 7–8. The strain had iso-C_15 : 0 3-OH (17·4 %), iso-C_15 : 0 (16·7 %), anteiso-C_15 : 0 (15·1 %) and iso-C_16 : 0 3-OH (13·4 %) as predominant fatty acids. The DNA G+C content was 33·9 mol%. Based on the physiological, fatty acid composition and phylogenetic data presented, strain CL-TF09^T is considered to represent a novel genus and species of the family Flavobacteriaceae, for which the name Lutibacter litoralis gen. nov., sp. nov. is proposed. The type strain is CL-TF09^T (=KCCM 42118^T=JCM 13034^T).