• Journal of fish pathology
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• v.22 no.1
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• pp.53-65
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• 2009

Tenacibaculum maritimum (formerly Flexibacter maritimus) is the aetiological agent of an ulcerative and necrotic disease commonly called tenacibaculosis in marine fish. Tenacibaculosis is an economically important disease in a great variety species in Jeju Island cultured fish and leading to this pathogen initially affected by skin, mouth, fins, tail causing severe necrotic and ulcerative lesions on the body surface. In the present study, A-7 strain was isolated from Paralichthys olivaceus showing symptoms of tenacibaculosis and identified as T. maritimum by morphological, biochemical and molecular biological analysis. T. maritimum A-7 is experimentally infected through immersion route in Paralichthys olivaceus which the disease outbreaks in land-based fish tanks of Jeju Island. Up to data a number of treatments proposed for the tenacibaculosis outbreaks are based on the immersion administration of drugs in tank. Oxytetracycline is the most widely used disinfectants in fish farms. However, most of fish farms manager and consumers have expressed concern as bioaccumulation in tissue and its environmental. In addition, this antimicrobial compounds is expensive in fish farmers. The overcome of this problem is desired the application of natural plant derived products. To obtain as 70% EtOH extract antimicrobial compounds against tenacibaculosis from 35 species of Jeju Island native plants were screened for antimicrobial activity against T. maritimum. In the present study were identified most of the plant extracts were better antimicrobial activity against T. maritimum.

• Ocean and Polar Research
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• v.24 no.4
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• pp.345-357
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• 2002

Ecological characteristics on habitats and morphological features of the seagrass Zostera caulescens Miki in Korea were examined. The biogeographical distribution of Z. caulescens was confirmed in the south coast of the Korea. Zostera caulescens usually inhabits at the inner bay, where is sheltered from wave action and 3.0 to 6.5 m deep. The sediment in habitats is composed of very fine muddy sand or sandy mud. In morphology, Z. caulescens is easily distinguished from other species of the genus by the formation of vegetative canopy on the top of reproductive stems. The number of longitudinal ribs in testa was 24 revealed by scanning electron microscope (SEM) while the number of ribs in Z. marina has been often reported to be 16-20. Purplish anthocyanin spots were displayed on the surface when the testa was removed. We found that the size and shape of leaf epidermal cells in Z. caulescens were very different from those of Z. marina when the leaf cuticles were removed by maceration which could be useful characters for identifying Zostera species. The leaf of Z. caulescens displays two different casts of color when the fresh plant is closely observed. The margins of leaves appear brighter than the center of leaves due to the thickening by the development of paralleled venation in the middle of leaves. The comparison of two populations of Z. caulescens in Korea showed that they were considerably different in their shoot density and biomass. The shoot density and biomass at Gabae population was $367.3 m^{-2}\;and\;725.7g$ dry wt $m^P{-2}$ respectively, while those at Jukrim population were $112.5m^{-2}\;and\;392.0g\;dry\;wt\;m^{-2}$, respectively.

• Journal of Life Science
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• v.32 no.9
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• pp.734-741
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• 2022

Currently, around 40 million people worldwide are living with human immunodeficiency virus (HIV) infection making HIV a critical global health risk. Present therapies for HIV infection consist of drug cocktails that target different steps of the HIV life cycle to prevent infection, replication, and release of the virus. Due to its mutating nature, drug resistance coupled with side-effects of long-term drug use, novel strategies, and pharmaceuticals to treat and manage HIV infection are constant needs and continuously being studied. Plants allocate a major repertoire of chemical diversity and are therefore regarded as an important source of new bioactive agents that can be utilized against HIV. Since the early 1990s, upon recommendations of the World Health Organization, numerous studies reported phytochemicals from different structural classes such as flavonoids, coumarins, tannins and terpenes with strong inhibitory effects against HIV infection. The present review gathered and presented recent research (2021-present) on plant extracts and phytochemicals that exhibit anti-HIV properties with the aim of providing insights into future studies where ethnomedical and underutilized plant sources may yield important natural products against HIV. Considering the relation and importance of HIV treatment with current viral infection risks such as SARS-CoV-2, screening plants for anti-HIV agents is an important step towards the discovery of novel antivirals.

• Journal of Life Science
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• v.26 no.10
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• pp.1218-1223
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• 2016

Abalones are gastropod mollusks belonging to the genus Haliotis. Fishery products are continuously declining worldwide while abalone production from aquatic farms has considerably increased. Although abalones are regarded as very important marine resources and considered to have big potential in sea-food farming industry around world, the slow growth rate of Pacific abalones is considered to be one of the most serious problems. For the genetic improvements in cultured abalone, advances in various breeding techniques for abalone have been reached through the introduction of selection, crossbreeding, hybridization, and polyploidy in several commercially important abalone species. Six species of abalone have been reported to be distributed along the coasts of Korea: Haliotis discus hannai, Haliotis discus discus, Haliotis madaka, Haliotis gigantea, Haliotis diversicolor diversicolor, and Haliotis diversicolor supertexta. The hybridization between these abalones may be one of the advanced technologies, and the preliminary experiments of interspecific hybrids between abalone species distributed in northern pacific areas including Korea, China, and Japan have been conducted. In this study, we reviewed the phylogenetic relationship of northern pacific abalone species which have the potential traits for aquaculture in Korea and their identifications. We also examined the development of molecular markers and some other aspects of the genetic approaches for successful development of hybrids.

• Preventive Nutrition and Food Science
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• v.13 no.4
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• pp.313-320
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• 2008

Efficiency of a far-infrared radiation (FIR) dryer for drying of citrus by-products (CBPs) was evaluated through their antioxidant activities. The CBPs dried through FIR were enzymatically digested by six carbohydrases (AMG, Celluclast, Pectinase, Termamyl, Ultraflo and Viscozyme) to prepare digests for evaluation of the activities. The total polyphenolic and total flavonoid contents of the digests were determined by colorimetric assays. The AMG digest was selected for the further experiments. The antioxidant potential of the digests were evaluated by DPPH, superoxide, hydroxyl and alkyl radical scavenging activities, $H_2O_2$ scavenging activity, metal chelating, lipid peroxidation inhibition and the reduction of DNA damage. The AMG digest from CBPs dried through FIR at $50^{\circ}C$ showed strong antioxidant activities in DPPH, superoxide, hydrogen peroxide, alkyl and metal chelating assays while all the digests showed strong lipid peroxidation activities. Further, enzymatic digests showed remarkable inhibitory activities against $H_2O_2$-induced DNA damage. Hence, the data obtained using different in vitro models clearly established the antioxidant potential of enzymatic digests from CBPs dried through FIR. Furthermore, they can be used as a source of natural antioxidants; hence, far-infrared radiation drying is a viable method for transforming wet CBPs into a dried form without destroying the bioactive components.

• Journal of fish pathology
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• v.34 no.1
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• pp.1-7
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• 2021

Red sea bream iridovirus (RSIV), belonging to the genus Megalocytivirus, is the predominant cause of mortality in marine fishes in Korea, including rock bream (Oplegnathus fasciatus). Rockfish (Sebastes schlegelii) are the host fish for RSIV, exhibiting no clinical signs or mortality. Cohabitation challenges, which mimicked natural transmission conditions, were performed to evaluate viral transmission between rock bream and rockfish, and to determine the pathogenicity and viral loads. In cohabitation challenge, artificially RSIV-infected rock bream were the viral donor, and healthy rockfish were the recipient. The results showed that although the donor rock bream had 95-100 % cumulative mortality (>10⁸ viral genome copies/mg of spleen 7-14 days after viral infection), the recipient rockfish did not die, even when the viral genome copies in the spleen were >10⁵ copies/mg. These results indicated asymptomatic infections. Notably, in a reverse-cohabitation challenge (artificially RSIV-infected rockfish as the viral donor and healthy rock bream as the recipient), RSIV horizontally infected from subclinical rockfish to rock bream (10⁷ viral genome copies/mg of spleen 21 days after cohabitation) with 10-20% cumulative mortality. These results suggest that an asymptomatic, infected rockfish can naturally transmit the RSIV without being sacrificed.

• Journal of Life Science
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• v.33 no.9
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• pp.703-712
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• 2023

Angiogenesis, the formation of blood vessels from pre-existing vessels, is a multistep process regulated by modulators of angiogenesis. It is essential for various physiological processes, such as embryonic development, chronic inflammation, and wound repair. Dysregulation of angiogenesis causes many diseases, such as cancer, autoimmune diseases, rheumatoid arthritis, cardiovascular disease, and delayed wound healing. However, the number of effective anti-angiogenic drugs is limited. Recent research has focused on identifying potential drug candidates from natural sources. For example, marine natural products have been shown to have anti-cancer, anti-oxidant, anti-inflammatory, antiviral, and wound-healing effects. Thus, this study aimed to describe the angiogenesis inhibitory effect of Hizikia fusiforms (brown algae) extract. The hexane extract of H. fusiformis has shown inhibitory effects on in vitro angiogenesis assays, such as cell migration, invasion, and tube formation in human umbilical vein endothelial cells (HUVECs). The hexane extract of H. fusiformis (HFH) inhibited in vivo angiogenesis in a mouse Matrigel gel plug assay. In addition, the protein expression of vascular endothelial growth factor (VEGF), mitogen-activated protein kinase (MAPK)/extracellular signal kinase, and AKT serine/threonine kinase 1 decreased following treatment with H. fusiformis extracts. Our results demonstrated that the hexane extract of H. fusiformis (HFH) inhibits angiogenesis in vitro and in vivo.

• Microbiology and Biotechnology Letters
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• v.50 no.1
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• pp.22-30
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• 2022

Haliotis discus hannai called abalone, is the valuable marine mollusks and the by-products of abalone processing are viscera. Brownish abalone male viscera (AMV), which have not been reported as having anti-inflammatory effects, was extracted with acetone and fractionated by different six acetone/hexane ratios (0, 10, 20, 30, 40, and 100%) using a silica column via in vitro ABTS and DPPH radical and nitric oxide (NO) production assay-guided fractionation. Among the fractions, the acetone/hexane ratio 40%, A40 exhibited the most potent radical scavenging activities and inhibition of lipopolysaccharide (LPS)-induced NO production without cytotoxicity. A40 inhibited LPS-induced intracellular reactive oxygen species (ROS) production in a dose-dependent manner. Western blot analysis revealed that A40 down-regulated the activation of NF-κB, MAPK (ERK 1/2, p-38, and JNK), and inflammatory enzymes, inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)-2. Moreover, this fraction inhibited the generation of pro-inflammatory cytokines such as interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α. These results suggested that AMV containing A40 with anti-inflammatory and anti-oxidantive effects, is the effective therapeutic and functional material for treating inflammatory disorders.

• Journal of the Korea institute for structural maintenance and inspection
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• v.24 no.1
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• pp.1-7
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• 2020

As of 2018, Steel slag was generated approximately 24.23 million tons. Howeve, except blast furnace slag, steel slag is a typical by-product which does not have a clearly defined purpose in recycling. Thus, countries around the world are putting great efforts into developing a purpose for the recycling of steel slag. The vast habitat foundation of marine life has been destroyed due to recent reckless marine development and environment pollution, resulting in intensification of the decline of marine resources, and a solution to this issue is imperative. In order to propose a method to recycle large amounts of by-product slag into a material that can serve as an alternative to natural aggregate, the engineering properties and applicability for each mixing factor of environment friendly porous concrete as a material for the composition of seawater purification were in this study. Regarding the nutrient elution properties, it was clear that the nutrients continuously flowed out up to an immersion time by 8 months in natural seawater; the nitrogenous fertilizer displayed excellent elution properties in this regard.

• Korean Journal of Food Science and Technology
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• v.36 no.6
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• pp.1020-1025
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• 2004

In previous paper, contaminations of food-borne pathogenic bacteria of Saengshik was found to occur during processing, because detection rates of food-borne pathogenic bacteria in final products were higher than those of raw materials. In this study, methods to reduce food-borne pathogenic bacteria and improved manufacturing process were developed for microbial safety of Saengshik. Food-borne pathogenic bacteria in raw materials were reduced to about 0.5-2.0 log cfu/g when seven kinds of raw materials were washed with electrolyzed water and ozonated water, but food-borne pathogenic bacteria could not be removed completely. After improvement of manufacturing process, numbers of food-borne pathogenic bacteria were same or decreased to levels of raw materials. Gaseous ozone and Biocon could control air-borne bacteria under $1{\times}10^1$ cfu/1000 L of air in pulverization and mixing rooms.