Jin-Sook Park

Analysis of bacterial diversity in sponges collected off Chujado, an Island in Korea, using barcoded 454 pyrosequencing: Analysis of a distinctive sponge group containing Chloroflexi

The bacterial diversity of 14 sponges belonging to 5 different orders that were collected around Chuja Island, Korea was investigated using barcoded 454 pyrosequencing. The sponges contained many unidentified bacterial groups (e.g. more than half of the taxa at the family level) that were known only in environmental sequences and obtained from culture-independent methods. Five of the sponges were clustered into one notable group (CF group), which was distinguished from the other sponges in accordance with bacterial composition (the other sponges may be separated into more groups but clustering is not clear). The CF group contained high amounts of Chloroflexi (25.0–47.7%) and moderate amounts of Gemmatimonadetes (2.3–7.0%), AncK6 (0.6–2.2%), PAUC34f (0.8–6.0%), Acidobacteria (3.7–9.6%), and SBR1093 (1.8–5.6%) exclusively or almost exclusively to this group. Sponges in the CF group also showed higher diversity (e.g. Shannon index) than the other sponges and contained group-specific taxonomic lineages (e.g. class or family level) from group-specific phyla and even from the Proteobacteria and Actinobacteria, which were detected in all sponges at the phylum level. The CF group may be one of the most distinctive groups in sponges in terms of bacterial diversity.

Sphingomonas jejuensis sp. nov., isolated from marine sponge Hymeniacidon flavia

A Gram-negative, non-motile, rod shaped, and orange-pigmented chemoheterotrophic bacterium, strain MS-31T was isolated from the marine sponge Hymeniacidon flavia, collected from near Jeju Island, Korea. The Strain MS-31T was subjected to a polyphasic taxonomic study. The phylogenetic analysis based on the 16S rRNA gene sequences revealed that the novel isolate could be affiliated within the genus Sphingomonas. The strain MS-31T showed 95.6% of 16S rRNA gene sequence similarity with the most closely related species Sphingomonas koreensis JSS26T. The DNA G+C content of the strain MS-31T was 69.4 mol%. The major isoprenoid quinone was ubiqunone 10 and predominant cellular fatty acids were summed feature 7 (comprising C18:1 ω7c, C18:1 Ω9t and/or C18:1 ωl2t, 39.7%), C16:0 (16.3%), C14:0 2OH (15.9%) and summed feature 3 (comprising C16:1 ω7c and/or C15:0 iso 2OH, 11.7%). The polar lipids were sphingoglycolipid, phosphatidyletha-nolamine, phosphatidylglycerol, diphosphatidylglycerol and unidentified glycolipid. Based on the evidence from the polyphasic taxonomic study, the strain should be classified as a new species of the genus Sphingomonas. As a result, the name Sphingomonas jejuensis sp. nov. (type strain MS-31T =KCTC 23321T =NBRC 107775T) is proposed.

Analysis of bacterial diversity in sponges collected from chuuk and kosrae islands in micronesia

The bacteria resident in sponges collected from Chuuk Lagoon and Kosrae Island of Micronesia were investigated using the 16S rRNA gene PCR-tagged pyrosequencing method. These sponges were clustered into 5 groups based on their bacterial composition. Diversity indexes and cumulative rank abundance curves showed the different compositions of bacterial communities in the various groups of sponges. Reads related to the phylum Chloroflexi were observed predominantly (9.7–68.2%) in 9 sponges of 3 groups and unobserved in the other 2 groups. The Chloroflexi-containing group had similar bacterial patterns at the phylum and lower taxonomic levels, for example, significant proportions of Acidobacteria, Gemmatimonadetes, SBR1093, and PAUC34f were observed in most members of this group. The three groups in the Chloroflexi-containing group, however, showed some minor differences in the composition and diversity. The other two groups contained high proportions of Proteobacteria (>87%) or Bacteroidetes (>61%) and different composition and diversity compared to the Chloroflexi-containing group and each other. Four pairs of specimens with the same species showed similar bacterial profiles, but, the bacteria in sponges were highly specific at the individual level.

Lysobacter spongiae sp. nov., isolated from spongin

A Gram-negative, motile, aerobic and rod-shaped bacterial strain designated 119BY6-57T was isolated from spongin. The taxonomic position of the novel isolate was confirmed using the polyphasic approach. Strain 119BY6-57T grew well at 25–30°C on marine agar. On the basis of 16S rRNA gene sequence similarity, strain 119BY6-57T belongs to the family Xanthomonadaceae and is related to Lysobacter aestuarii S2-CT (99.8% sequence similarity), L. maris KMU-14T (97.5%), and L. daejeonensis GH1-9T (97.3%). Lower sequence similarities (97.0%) were found with all of the other recognized members of the genus Lysobacter. The G + C content of the genomic DNA was 69.9 mol%. The major respiratory quinone was Q-8 and the major fatty acids were C16:0 iso, C15:0 iso, summed feature 9 (comprising C17:1 iso ω9c and/or C16:0 10-methyl), summed feature 3 (comprising C16:1ω7c and/or C16:1ω6c), and C11:0 iso 3-OH. The polar lipids were phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol, three unidentified phospholipids, and an unidentified polar lipid. DNADNA relatedness values between strain 119BY6-57T and its closest phylogenetically neighbors were below 48.0 ± 2.1%. Based on genotypic and phenotypic characteristics, it is concluded that strain 119BY6-57T is a new member within the genus Lysobacter, for which the name Lysobacter spongiae sp. nov. is proposed. The type strain is 119BY6-57T (= KACC 19276T = LMG 30077T).

Nanocomposite Hydrogel Adhered to Concrete Material for Aquaculture of Marine Organism

Nanocomposite (NC) hydrogels based on N,N′-dimethyl acrylamide (DMAAm) using Laponite were prepared. The mechanical properties, adhesive properties to concrete material, and bio-fouling behavior of microalgae Nitzschia sp. were investigated. The elongation and fracture strength of the NC hydrogels were greatly increased and the elastic modulus was decreased in comparison with those of typical hydrogels prepared by using the organic cross-linking agent N,N′-methylenebis(acrylamide) (MBAA). In case of NC hydrogels, they had excellent adhesion properties to the concrete material. The adherence of microalgae on the NC hydrogel surface was also much higher. As the concentration of Laponite in the nanocomposite hydrogels increased, the elastic modulus and fracture strength increased, and the elongation at break, peeling force, and peeling energy were found to be at a maximum at certain concentrations.

Bacillus spongiae sp. nov., isolated from sponge of Jeju Island

A Gram-reaction-positive, strictly aerobic, motile, endospore- forming, and rod-shaped bacterial strain designated 135PIL107-10T was isolated from a sponge on Jeju Island, and its taxonomic position was investigated using a polyphasic approach. Strain 135PIL107-10T grew at 20–37°C (optimum temperature, 25°C) and pH 6.0–10.0 (optimum pH, 6.0) on marine and R2A agars. Based on 16S rRNA gene phylogeny analysis, the novel strain formed a new branch within the genus Bacillus of the family Bacillaceae, and formed clusters with Bacillus thaohiensis NHI-38T (96.8%), Bacillus fengqiuensis NPK15T (96.7%), and Bacillus songklensis CAU 1033T (96.7%). Lower sequence similarities (97.0%) were found with the type strains of all other recognized members of the genus Bacillus (95.6–96.8% similarity). The G + C content of the genomic DNA was 43.6 mol%. The predominant respiratory quinone was menaquinone-7 and the major fatty acids were iso-C15:0 and iso-C17:1ω10c. The overall polar lipid patterns were diphosphatidylglycerol, phosphatidylglycerol, and phosphatidylethanolamine. The diagnostic diamino acid in the cell-wall peptidoglycan was meso-diaminopimelic acid. The isolate therefore represents a novel species, for which the name Bacillus spongiae sp. nov. is proposed, with the type strain 135PIL107-10T (= KACC 19275T = LMG 30080T).

Aquimarina spongiicola sp. nov., isolated from spongin

A Gram-reaction-negative, aerobic, motile by gliding, non-spore-forming, rod-shaped bacterial strain, designated 122CH820-2T, was isolated from spongin. This bacterium was characterized to determine its taxonomic position by using a polyphasic approach. Strain 122CH820-2T grew well at 25-30 °C on marine agar. On the basis of 16S rRNA gene sequence similarity, strain 122CH820-2T belonged to the family Flavobacteriaceae and was closely related to Aquimarina mytili PSC33T (96.8 % sequence similarity) and A. penaei P3-1T (96.7 %). Lower sequence similarities (<96.5 %) were found with all of the other recognized members of the genus Aquimarina. The G+C content of the genomic DNA was 35.2 mol%. The major respiratory quinone was menaquinone MK-6 and the major fatty acids were C15 : 0, iso-C17 : 0 3-OH, iso-C15 : 1 G and iso-C15 : 0 3-OH. The polar lipids were phosphatidylethanolamine, one aminophospholipid and five unidentified polar lipids. Strain 122CH820-2T could be differentiated genotypically and phenotypically from recognized species of the genus Aquimarina. The isolate therefore represents a novel species, for which the name Aquimarina spongiicola sp. nov. is proposed, with the type strain 122CH820-2T (=KACC 19274T=LMG 30078T).