https://repository.kopri.re.kr/handle/201206/5081 Tue, 07 Apr 2026 05:03:14 GMT 2026-04-07T05:03:14Z https://repository.kopri.re.kr/handle/201206/5984 Title: Lessons from the Sea: Complete Genome Sequence of a Marine Bacterium Hahella chehuensis and Its Algicidal Pigment Authors: Jeong, Haeyoung; Oh, T.K.; Kim, Ji Hyun; Lee, Hong Kum; Yoon, Sung Ho Abstract: Harmful algal blooms (HABs or red tides), caused by uncontrolled proliferation of marine phytoplankton, impose a severe environmental problem and occasionally threaten even public health. We found that an EPS-producing bacterium Hahella chejuensis isolated from a marine sediment sample also produces a red pigment that kills red-tide dinoflagellates at the parts per billion level. H. chejuensis is the first sequenced species among algicidal bacteria as well as in the order Oceanospirillales. Sequence analysis showed a distant relationship to the Pseudomonas group. Its 7.2-megabase genome encodes basic metabolic functions and a large number of proteins involved in regulation or transport. One of the prominent features of the H. chejuensis genome is a multitude of genes of functional equivalence or of possible foreign origin. A significant proportion (~23%) of the genome appears to be of foreign origin, i.e. genomic islands, which encode genes for biosynthesis of exopolysaccharides, toxins, polyketides or non-ribosomal peptides, iron utilization, motility, type III protein secretion and pigment production. Molecular structure of the algicidal pigment was determined to be prodigiosin by LC-ESI-MS/MS and NMR analyses. Our work suggests a new possibility for controlling algal blooms by exploiting biotic interactions in the natural environment and provides a research model in marine bioprospecting through genome research. Sun, 01 Jan 2006 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5984 2006-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5671 Title: Culturable actinobacteria from the marine sponge Hymeniacidon perleve: isolation and phylogenetic diversity by 16S rRNA gene-RFLP analysis Authors: Lee, Yoo Kyung; Haitao Zhang; Wei Zhang; Lee, Hong Kum Abstract: A total of 106 actinobacteria associated with the marine sponge Hymeniacidon perleve collected from the Yellow Sea, China were isolated using eight different media. The number of species and genera of actinobacteria recovered from the different media varied significantly, underlining the importance of optimizing the isolation conditions. The phylogenetic diversity of the actinobacteria isolates was assessed using 16S rRNA gene amplification-restriction fragment length polymorphism (RFLP) analysis of the 106 strains with different morphologies. The RFLP fingerprinting of selected strains by HhaI-digestion of the 16S rRNA genes resulted in 11 different patterns. The HhaI-RFLP analysis gave good resolution for the identification of the actinobacteria isolates at the genus level. A phylogenetic analysis using 16S rRNA gene sequences revealed that the isolates belonged to seven genera of culturable actinobacteria including Actinoalloteichus, Micromonospora, Nocardia, Nocardiopsis, Pseudonocardia, Rhodococcus, and Streptomyces. The dominant genus was Streptomyces, which represented 74% of the isolates. Three of the strains identified are candidates for new species. Sun, 01 Jan 2006 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5671 2006-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5676 Title: The study of antagonistic interactions among pelagic bacteria: a promising way to coin environmental friendly antifouling compounds Authors: Cho, Kyeung Hee; Lee, Hong Kum; Lee, Yoo Kyung; Hari Datta Bhattarai; Shin, Hyun Woung Abstract: Ten strains of marine bacteria (SCH0401-SCH0410) were isolated from Ayajin, the east coast of South Korea. In spectrophotometer based chemotaxis assay the ethyl acetate extract (300 mu g) of SCH0402 decreased the optical density (OD) of the motile target strains SCH0401, SCH0402, SCH0407 and SCH0408 by two to six times when compared to control. Tributyltin oxide (TBTO) decreased the OD of all target strains by only two times. The most active strain SCH0402 was identified as Shewanella oneidensis by using 16S rDNA gene sequence analysis. Similarly, the target motile strains SCH0401, SCH0402, SCH0407 and SCH0408 were identified as Alteromonas marina, Shewanella oneidensis, Roseobacter gallaeciensis and Bacillus atrophaeus, respectively. The growth inhibition zone produced by the test bacterial extracts against the target strains were three to eight times smaller when compared to that of TBTO. Even though, SCH0402 showed six times weaker antibacterial activity, the repellent activity was three times stronger than TBTO. Therefore, the higher negative chemotactic activity would be better to select eco-friendly antifouling compounds than the other antibacterial activities. Sun, 01 Jan 2006 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5676 2006-01-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/5826 Title: Costertonia aggregata gen. nov., sp., nov., a mesophilic marine bacterium of the family Flavobacteriaceae, isolated from a mature biofilm Authors: Kwon, K.K.; Lee, Hong Kum; Lee, Yoo Kyung Abstract: A marine bacterium, KOPRI 13342T, was isolated from a mature marine biofilms including various marine algae covered on a rock-bed of the East Sea, Korea. The strain produces an orange-coloured colony on marine agar 2216. The isolate showed relatively high 16S rRNA gene sequence similarities with members of the genera Maribacter (91.2-92.4% similarity), Zobellia (90.7-91.5%), and Muricauda (90.7-91.4%). Phylogenetic analysis based on nearly complete 16S rRNA gene sequence revealed that the isolate formed a phyletic lineage with members of the genus Muricauda. The cells were aerobic motile Gram-negative rods and produce non-diffusible carotenoid pigments. The optimal growth required the presence of 3 % (w/v) seasalt, pH 7.5-8.0 and 26-32 oC. The strain required Ca2+, K+, Mg2+ and CO32- in addition to the NaCl for growth. The dominant fatty acids are i-15:0, i-15:1, 15:0 and 16:1ω9. The major respiratory quinone is MK-6. The DNA G+C ratio is 35.8 mol%. On the basis of these polyphasic taxonomical evidences, strain KOPRI 13342T should be classified as a novel genus in the family Flavobacteriaceae and it is proposed as Costertonia aggregata gen. no., sp. nov. The type strain is KOPRI 13342T (=KCCM 42265T =JCM 13411T). Sun, 01 Jan 2006 00:00:00 GMT https://repository.kopri.re.kr/handle/201206/5826 2006-01-01T00:00:00Z