Bacillus subtilis CH1으로부터 생산되는 키토산아제의 분리, 정제 및 특성 분석

오철홍,이제희 한국양식학회 2006 韓國養殖學會誌 Vol.19 No.1

Phylogenetic, Histological and Age Determination for Investigation of Non-native Tropical Black-lip Pearl Oyster, Pinctada margaritifera, Settled in Jeju, Korea

오철홍,김진경,손영백,주세종,정희도,양현성,최광식,Gilles Le Moullac,강도형 한국해양과학기술원 2017 Ocean science journal Vol.52 No.4

This study reports the first finding of tropical blacklip pearl (BLP) oyster, Pinctada margaritifera, in Korean waters. One BLP oyster was found and sampled from Beom-seom islet (33°13′N, 126°33′E) in the southern coast of Jeju Island, Korea in February, 2011. The taxonomic status of the specimen was confirmed by nucleotide sequences of the mitochondrial gene cytochrome oxidase I and 28S ribosomal DNA. Oxygen isotopic analysis (δ18Osh) and histology were used to determine the specimen’s age and reproductive stage, which were 3.5 years and ripe male, respectively. This BLP oyster most likely originated in an area in the subtropics or tropics, such as the Okinawa archipelagic or Micronesian regions. We suggest that intensive monitoring surveys are necessary for confirming the northward expansion of BLP oyster in Korean waters in the near future.

Isolation, Purification and Characterization of Chitosanase from Bacillus subtilis CH1

Chulhong Oh(오철홍),Jehee Lee(이제희) 한국수산과학회 양식분과 2006 韓國養殖學會誌 Vol.19 No.1

수산부산물에 대한 해양바이오산업 활용 의향 조사 연구

장덕희,오철홍,안소언 (사)한국해양바이오학회 2023 한국해양바이오학회지 Vol.15 No.2

This study examines a business survey on the utilization of fishery by-products with the aim to assess the feasibility of incorporating these by-products into various industries. The research involved surveying 312 biocompanies across the country and conducting an empirical analysis based on the collected data. South Korea, a leading seafood-producing country with a developed seafood processing industry, provides conditions necessary to utilize seafood by-products as raw materials for the marine bioindustry. Among the surveyed biocompanies, 38.5% expressed their intention to engage in industrial activities involving the use of fishery by-products in the future, indicating a significant level of interest within the bioindustry in utilizing marine and fishery by-products. Companies showed interest in diverse materials, such as scales, fish bones, skin, and kelp holdfast beyond those currently defined under the Fisheries By-products Recycling Promotion Act (officially unnamed, 2021). This suggests a need for improvements in the regulatory framework to accommodate these diverse biomaterials. Furthermore, we propose enhancing the efficiency of fishery by-product utilization by focusing on regional specialization in marine bioindustry. This involves utilizing existing legal framework for upcycling fishery by-products and fostering a regionally specialized marine bioindustry.

바이오 기업의 해양바이오 분야 진입을 위한 기업수요 분석

장덕희,강예린,오철홍,도수관 한국해양과학기술원 2017 Ocean and Polar Research Vol.39 No.3

This study seeks to analyze the needs of biotechnology companies in relation to their entry into the marine biotechnology industry and to discuss the policy implications associated with empirical tasks based on issues raised from empirical results gathered from a survey data of 200 biotechnology companies in Korea. This study made a comparison between marine and non-marine biotechnology companies and analyzed non-marine biotechnology companies’ needs related to their entry into the marine biotechnology companies by using Social Network Analysis (SNA). Empirical results indicate that 23.5% of biotechnology companies produce goods using marine bio-resources. Once the utility of marine bioresources is established, 58.8% of non-marine biotechnology companies intend to enter the marine biotechnology industry. This study also shows that non-marine biotechnology companies need technical support, information sharing, and the acquisition of raw materials to enter the marine biotechnology industry. The findings in this study provide important pointers for the direction of policies and future research in the area of marine biotechnology industry.

미세조류 바이오연료 상용화를 위한 주요 인자 연구

강도형,허수진,오철홍,주세종,전선미,최현우,노재훈,박세헌,김태영 한국해양과학기술원 2012 Ocean and Polar Research Vol.34 No.4

Microalgae are photosynthetic microorganisms that are highly productive in the presence of basic renewable natural sources (light, CO2, water and nutrients). They can synthesize lipids, carbohydrates and proteins in a small number of days. Subsequently, these carbon-captured products can be processed into both biofuels and valuable co-products. Additionally, microalgae would be an ideal feedstock for replacing land-based food crops with cellular products as high energy density transportation fuels. These microscopic organisms could contribute a significant amount of renewable energy on a global scale. In Korea, microalgae biofuel research was common in the early 1990s. The research activities were unfortunately stopped due to limited governmental funds and low petroleum prices. Interest in algal biofuels in Korea has been growing recently due to an increased concern over oil prices, energy security, greenhouse gas emissions, and the potential for other biofuel feedstock to compete for limited agricultural resources. The high productivity of microalgae suggests that much of the Korean transportation fuel requirements can be met by biofuels at a production cost competitive with the increasing cost of petroleum seen in early 2008. At this time, the development of microlalgal biomass production technology remains in its infancy. This study reviewed microalgae culture systems and biomass production, harvesting, oil extraction, conversion, and technoeconomical bottlenecks. Many technical and economic barriers to using microalgal biofuels need to be overcome before mass production of microalgal-derived fuel substitutes is possible. However, serious efforts to overcome these barriers could become a large-scale commercial reality. Overall, this study provides a brief overview of the past few decades of global microalgal research.

Characterization of a Glycoside Hydrolase Family 50 Thermostable β-agarase AgrA from Marine Bacteria Agarivorans sp. AG17

NIKAPITIYACHAMILANI LALANTHI,오철홍,이영득,이숙경,황일손,이제희 한국수산과학회 2010 Fisheries and Aquatic Sciences Vol.13 No.1

An agar-degrading Agarivorans sp. AG17 strain was isolated from the red seaweed Grateloupia filicina collected from Jeju Island. A beta-agarase gene from Agarivorans sp. AG17 was cloned and designated as agrA. agrA has a 2,985 bp coding region encoding 995 amino acids and was classified into the glycoside hydrolase family (GHF)-50. Predicted molecular mass of the mature protein was 105 kDa. His-tagged agrA was overexpressed in Escherichia coli and purified as a fusion protein. The enzyme showed 158.8 unit/mg specific activity (optimum temperature at 65°C and pH 5.5 in acetate buffer) with unique biochemical properties (high thermal and pH stabilities). Enzyme produced neoagarohexaose, neoagarotetraose and neoagarobiose by degrading agar, and hydrolyzed neoagaro-oligosaccharides were biologically active. Hence the purified enzyme has potential for use in industrial applications such as the development of cosmetics and pharmaceuticals.

Profiles of teleost DNA fragmentation factor alpha and beta from rock bream (Oplegnathus fasciatus): molecular characterization and genomic structure and gene expression in immune stress

이숙경,이제희,황일선,오철홍,이영덕,김유철,김효원,Qiang Wan 한국유전학회 2016 Genes & Genomics Vol.38 No.2

Apoptosis serves to protect normal cells during the processes of development, aging, tissue homeostasis, immunity, and inflammation. Molecules such as caspases, the Bcl-2 family proteins, cytochrome c, APAF-1, and apoptotic endonucleases are concerned with and regulate different stages of apoptosis. DNA fragmentation factor (DFF) is a key final molecule in chromosomal DNA fragmentation during the last step of apoptosis, and is a heterodimeric complex consisting of alpha/inhibitor of caspase-activated DNase (DFFA/ICAD) and beta/caspaseactivated DNase (DFFB/CAD) subunits. DFFB/CAD is normally combined with the inhibitor, DFFA/ICAD, in healthy cells. However, after cleavage of the DFF complex by effector caspases, DFFB/CAD acts as an apoptotic nuclease and induces DNA fragmentation in apoptotic cells. The study of DFF proteins is focused on the roles of the apoptotic pathway in mammals. However, gene expression and functions under immune stimulation are not well known in other species. In the present study, we first characterized teleost DFFA/ICAD and DFFB/CAD from rock bream at the molecular level and analyzed the transcriptional expression pattern under immune challenges, to understand their role in immunity. These putative proteins have shown conserved domains and interaction sites orthologous to those of other species. High mRNA expression of both genes was found in the gills and blood of tissues involved in the immune response. The increased expression of DFF genes upon bacterial and viral stimulation was confirmed by qPCR analysis. DFFA/ICAD and DFFB/CAD of rock bream may play a pivotal role in apoptosis and may be involved in host immunity against bacterial and viral infection.

Reproductive Characteristics of the Humbug Damselfish, Dascyllus aruanus, in Chuuk Lagoon, Micronesia

최영웅,박미애,이균우,오철홍,박흥식 한국해양과학기술원 2014 Ocean science journal Vol.49 No.4

This study was conducted to investigate the reproductive characteristics of the humbug damselfish, Dascyllus aruanus, through the measurement of gonadosomatic indices (GSI) and histological examination of the gonads. Fish were collected from Chuuk Lagoon, Micronesia (7°27'N; 151°53'E), between August 2009 and July 2010. Overall, the functional sex ratio was approximately 1:1; however, there was a female bias in the smaller size range (35 - 40 mm standard length [SL]) and male bias in the larger sizerange (45 - 60 mm in SL). The process of oocyte development exhibited a group synchronous pattern, from the vitellogenic phase oocytes in the gonads following the two clutches of oocytes, as the primary growth stage and yolk vesicle stage. The testis with an ovarian lumen exists as a central slit, and the sperm ducts extend into the medial hilar region of the gonads, indicating that males of D. aruanus have a secondary testis of protogynous species. Monthly variations in the GSI and evolution of gonad status indicated that reproductive activity in this species occurs throughout the year in Chuuk Lagoon, Micronesia.

Induction of Apoptosis by the Tropical Seaweed Pylaiella littoralis in HT-29 Cells via the Mitochondrial and MAPK Pathways

예보람,김준성,김민선,장지이,오철홍,강도형,Zhong-Ji Qian,정원교,최일환,허수진 한국해양과학기술원 2013 Ocean science journal Vol.48 No.4

We demonstrated that an extract from Pylaiella littoralis, collected from the Federate States of Micronesia (FSM), could inhibit the proliferation of tumor cells. P. littoralis extract (PLE) showed anti-proliferative activities in the tumorigenic cells tested, ranging from 20.2% to 67.9%. The highest inhibitory activity, in HT-29 cells, was selected for further experiments. PLE showed no cytotoxic effect in normal cells and inhibited the growt of HT-29 cells depending on concentration and incubation time. PLE-treated HT-29 cells showed the typical morphological characteristics of apoptosis, such as apoptotic body formation and DNA fragmentation. PLE also induced mitochondrial membrane potential depolarization and resulted in increased mitochondrial membrane permeability, compared with untreated cells. PLE decreased Bcl-2 protein and increased Bax protein expression, activating caspase-3 and poly (ADP-ribose) polymerase (PARP) expression via the caspase pathway. PLE also increased the phosphorylation of c-Jun N-termial kinase (JNK), p38, and extracellular signal-regulated kinase (ERK), and it reduced cell viability in treatment cells with specific inhibitors such as PD98059 (a specific inhibitor of ERK), SP600125 (a specific inbibitor of JNK), and SB 203580 (a specific inbibitor of p38 MAPK). via the the mitogen-activated protein kinases (MAPKs) pathway. These results suggest that PLE inhibits the proliferation of HT-29 cells by affecting the caspase and MAPK pathways involved in the induction of apoptosis. Thus, we suggest that P. littoralis extract might be potential candidate agents for the treatment of human colorectal cancer.