• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.273-274
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• 2006

The sea is origin of all lift, and 90% of the all living organisms are in the sea. The biosynthesis is very different. Many organisms are kept on a lower or developed to another evolutionary level than on shore. Our society is increasing demand and need for marine food and this food has to product at onshore or offshore fish farming sites. Ocean fish farms have a special operation properties such as a good quality water, net cage, sheltered locations and feeding system. The farming site is controlled and monitored for fish welfare as ammonia($NH_3$), temperature, the speed of a running fluid. Specially, the fish farm is seriously influenced by ammonia. In this paper, $NH_3$ monitoring system for ocean fish farm is researched for the suitable fish farming sites, and test equipment is designed for achieving practical data. The equipment wit monitoring algorithm is expected to the useful system for ocean fish farm.

• Korean Journal of Ichthyology
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• v.9 no.1
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• pp.22-29
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• 1997

Feeding habits of Pholis nebulosa collected from a eelgrass bed in Kwangyang Bay from January 1994 to December 1994 were studied. Pholis nebulosa was a carnivore which mainly consumed epiphytal amphipods. Its diets included minor quantities of caridean shrimps, isopods, copepods, tanaids and polychaetes. It showed ontogenetic changes in feeding habits. In an initial feeding stage, copepods were major food organisms. However, gammarid and caprellid amphipods were heavily selected with increasing fish size. Although gammarid and caprellid amphipods were major prey organisms for all seasons, the relative proportion of these two food items changed with season.

• Journal of Environmental Health Sciences
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• v.33 no.3
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• pp.180-183
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• 2007

Over the last century the mercury (Hg) concentration in the environment has been increased by human activities with inputs from sources such as atmospheric deposition, urban runoff, and industrial effluents. Mercury can be transformed to methylmercury (MeHg) in anaerobic conditions by sulfate reducing bacteria (SRB) and sediments are the principal location for MeHg production in aquatic environments. Interest in bioaccumulation of Hg and MeHg into lower trophic levels of benthic and pelagic organisms stems from public health concerns as these organisms provide essential links for higher trophic levels of food chains such as fish and larger invertebrates. Fish consumption is the major exposure route of MeHg to humans. Recently, it was reported that blood samples in Korea showed much higher Hg levels (5-8 times) than those in USA and Germany. Although this brings much attention to Hg research in Korea, there are very few studies on Hg biogeochemical cycling and bioaccumulation in aquatic environments. Given the importance of Hg methylation and MeHg transfer through food chains in aquatic environments, it is imperative that studies should be done in much detail looking at the fate, transport, and bioaccumulation of Hg and MeHg in the environment. Moreover, there should be long-term monitoring plans in Korea to evaluate the environmental and health effects of Hg and MeHg.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.175-180
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• 2011

The investigated amounts according to microalgae for stable supply of artificial seed of the hard clam, Meretrix petechialis and also observed the effect according to the repower of the microalgae after the specified period starvation. The stage of specimen used in the test was the D-shaped larva. The microalgae was Chaetoceros calcitrans, Isochrysis galbana and Nannochloris oculata. When the mixture of Chaetoceros calcitrans, Isochrysis galbana and Nannochloris oculata or alone C. calcitrans as food was supplied with 3,000-5,000 cells/ind., it turned to be the most effective. When the food was provided after starvation for some period, the shell length of D-shaped larva was grown to over $192.5{\mu}m$ at fourth day from the initial feeding. The survival rate tended to be lower, the longer the starvation period.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.1
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• pp.180-185
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• 2016

To investigate the feeding habits of Tridentiger trigonocephalus juveniles captured in the intertidal zone of Dodun-ri, Seocheon-gun from the end of May to early June 2012, the gut contents were observed. Feeding incidence of the juveniles increased twice a day, first in the morning and second in the afternoon. The major food organisms of the juveniles (6.5~10.0 mm NL) were composed of copepods (65.4%), amphipods (2.0%), shrimp larvae (14.5%), polychaete larvae (22.6%), and etc. These food items held more than 2 percentage in the dry weight of the total food items.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.184-187
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• 2008

S-Adenosyl-L-methionine (SAM) is an important metabolic intermediate in living organisms and participates in many reactions as a methyl group donor. SAM has been used as a dietary supplement and is proposed to have beneficial effects on the liver and brain. The aim of this study was to find lactic acid bacteria with high SAM-producing ability to be used as SAM enhancing probiotics. We used high performance liquid chromatography (HPLC) to quantify the amount of SAM produced, and found that Bifidobacterium bifidum BGN4 produced a significantly higher amount of SAM than other Bifidobacterium or Lactobacillus strains. The effect of various carbon and nitrogen sources on SAM production was examined. This study confirmed that Bifidobacterium may be utilized as a source of SAM in the functional food industry.

• Preventive Nutrition and Food Science
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• v.2 no.4
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• pp.310-315
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• 1997

Wild propionibacteria isolated from different commercial swiss cheese samples were tested for antimicrobial activities. In initial screening, six of these Propionibacterium isolates showed antagonistic activity against 10 selected indicator organisms by the deferred method. In next, only two Propionibacterium strains JW6 and JW14 showed antibacterial activity in the cell-free supernatants by the modified well diffusion method. Propionibacterium strains JW6 and JW14 were finally identified as bacteriocin producers which exhibited a bactericidal effect against closely related species. The antimicrobial substances were proteins, since their activities were completely destroyed following several degradative enzyme treatments. The bacteriocins showed a narrow inhibitory spectrum of activity against two propionibacteria and two bacilli of strains tested in this study.

• Food Science and Preservation
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• v.3 no.2
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• pp.149-154
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• 1996

In order to develovpment of new sterilizing method applied to food industry, effects of ozone treatment on microorganisms, associated with food hygiene were investigated. Microorganisms were immersed in water and sparged with ozonised air(ozone concentration, 3mg liter-1) at an air flow rate of 5 liter min-1. When organisms were treated with benzoic acid and sorbic acid of 0.4∼1.0g/$\ell$, respectively, they were not dectable perfectly. Sodium benzoate had an effect on Penicillium islandicum. When bacteria were sparged with ozonised air, Pseudomonas aeruginosa completely inhibited at 60 minutes, and the killing Aspergillus flavus and Penicillium islandicum. Also, all of bacteria were inactivated after immersed with ozonated water for 10minutes, but two fungal species were not effective.

• Food Science and Biotechnology
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• v.18 no.2
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• pp.425-431
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• 2009

Antimicrobial coating on chicken carcasses may reduce the effects of cross-contamination and improve product shelf-life and safety. Thyme oil was mixed at 0.5%(v/v) with a pre-gelatinized pea starch coating solution. The coating solution was spread on chicken breast meat after inoculation with selected spoilage and pathogenic bacteria. After inoculation, the chicken meats were packaged in plastic bags and stored at $4^{\circ}C$. During 12 day storage, total aerobic bacteria, lactic acid bacteria, and inoculated organisms were counted at 4 day intervals. Thyme oil treatments reduced the viability of Salmonella as well as the growth of Listeria and Pseudomonas by 2 log CFU/g, and appeared to eliminate inoculated Campylobacter during storage. The addition of thyme oil increased the viscosity of the pre-gelatinized pea starch solution. The results suggested that thyme oil inclusion in an edible starch coating may be a satisfactory delivery system to enhance the safety of processed fresh meat.

• Microbiology and Biotechnology Letters
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• v.13 no.1
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• pp.93-101
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• 1985

Much of the progress in genetic engineering has been accomplished by employing Escherichia coli as the host organism. For many reasons, however, some other organisms have greater potential as alternatives to E. coli. In particular, streptomycetes are attractive organisms as hosts especially for the producation of various secondary metabolites such as antibiotics. In this article, therefore, we reviewed the techniques for development of vector system and expression of genes for antibiotic biosynthesis in streptomycete hosts.