• Journal of Practical Agriculture & Fisheries Research
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• v.13 no.1
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• pp.115-129
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• 2011

This study was performed to investigate the effects of food organism and water quality on the mass production of larval red marbled rockfish, Sebastiscus tertius. When rotifer cultured with different food stuffs were supplied to the larvae, rotifer cultured with concentrated Chlorella provided the highest in total length 11.9 mm and survival rate was the highest by 47.0% fed that cultured with ω-yeast Growth and survival rate of larvae fed on enriched rotifer with ω-yeast and super selco, super selco of enriched treatment showed that the best results not only growth but also survival rate. For instance of Artemia, the growth was not significantly different with other treatment but the survival rate was significantly higher than others. The growth of larvae fed with different diets indicated that rotifer+Artemia+commercial diet treatment was the highest on the total length and body weight 18.40 mm and 18.1 mg, respectively, whether the survival rate was rotifer+Artemia treatment was the highest as 57.5%. The most effective density of Chlorella was 10×10⁵ cells/ml for growth of larvae. That density showed that total length and body weight were 11.83 mm and 14.3 mg, respectively. The survival rate was the most effective for 20×10⁵ cells/ml of Chlorella density. That density represented the highest survival rate as 54.5%. Comparing of PSB adding effect, PSB density 15×10⁵ cells/ml was the most effective for growth of larvae and but for survival rate PSB density 10×10⁵ cells/ml was the highest as 61.0%.

• Journal of fish pathology
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• v.6 no.1
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• pp.21-55
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• 1993

Histopathological changes in gills by potassium permanganate were investigated in four fish species. flounder(Pararychthys olivaceus) and rockfish(Sebastes schlegeli) in marine fish, and carp(Cyprinus carpio) and eel(Anguilla japonica) in freshwater fish. Marine fishies were more sensitive to $KMnO_4$ than freshwater fishies and have shown histological changes even in low concentration of 1ppm. Eels were less affected than carp in high concentration of $KMnO_4$. Especially in eels, hyperplasia and hypertropy of mucus cells were observed. Compared to in underground water. the effect of KMnO₄ were reduced very much in pond water. That this differences were due to the concentration of organic substances were certained by experiment with various feed concentrations. The potency of $KMnO_4$ were influenced by dissolved oxygen.

• Korean Journal of Agricultural Science
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• v.3 no.2
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• pp.235-243
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• 1976

As an investigation on the catabolite repression system in cellulase production by Cellulomons sp. CS1-1, the organism was tested on the avicel overlay plates containing glucose or cellobiose at a range of concentration and was grown in continuous culture vessel, supplied by cellobiose medium, aiming the enhanced production of extracellular CM-cellulase at low dilution rates. Product inhibition of cellulase action by cellobiose was also tested. The results obtained are: i) no inhibition of CM-cellulase was observed up to 10 mM(3.4mg/ml) cellobiose in the reaction mixture, however 30% inhibition was observed at 20mM and 55% at 50mM, ii) the tests of catabolite repression on the solid media were successful, and avicel degradation was markedly repressed by glucose or cellobiose, iii) at low concentrations of cellobiose, dilution rate 0.05 and $1.0hour^{-1}$, no significant increase was observed in the production of either intra or extracellular CM-cellulase.

• Journal of Aquaculture
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• v.11 no.1
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• pp.113-118
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• 1998

This study was carried out to investigate feeding of bacteria by Tigripus japonicus (Copepoda : Harpacticoida) under axenic culture. The ovigerous females and nauplii were grown with feed of aquatic bacteria. Growth of RT bacteria strain was suppressed by feeding of co-existing T. japonicus. T. japonicus of non-axenic culture was observed with oil bead in the egg sac. On the other hand, early nhauplius stage did not develop to the next stage without stage took bacteria as food. And the adult of T. japonicus may utilize the baxteria as nutrient source for egg development.

• KSBB Journal
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• v.19 no.1
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• pp.1-11
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• 2004

Chlorella contains a rich source of biochemical products with applications in the feed, food, nutritional, cosmetic, pharmaceutical and even fuels industries. Chlorella is one of unicellular green algae and is mostly grown in fresh water such as pond and lake. It grows in a manner of nonsexual reproduction so that it multiplies 4~16 times overnight. Large-scale culture is conducted by open pond culture or pure culture using fermenter. Chlorella has various efficacies such as heavy metal removal, degradation of toxic materials, control of arteriosclerosis, immunoprotective effects, anticancer activity and growth-stimulating activity of intestinal bacteria. Chlorella can be used as a taste enhancer and foodstuff, as it has a plenty of essential amino acids, polyunsaturated fatty acids, sterols and chlorella growth factor (CGF). Chlorella is a potential organism which can be utilized for CO$_2$ removal and H$_2$ Production in environmental area and energy Production.

• Journal of Aquaculture
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• v.19 no.4
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• pp.225-230
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• 2006

A long-term (26 weeks) feeding experiment was conducted to examine the essentiality and requirement of inositol in diets for olive flounder because no information is available in the species. Five casein-gelatin based semi-purified diets were formulated to contain four different levels of myo-inositol (0, 0+antibiotic, 400, 800, and 1600 mg/kg, designated as M0, M0+, M400, M800, and M1600, respectively). One (M0+) of the control diets contained tetracycline hydrochloride (0.4%, wt/wt) as an antibiotic to inhibit biosynthesis of inositol by micro-organism in intestine of fish. Olive flounder at the early juvenile stage (initial body weight 1.22 g) were randomly distributed into fifteen 35 L tanks (48 fish/tank) and fed with one of the experimental diets (3 replicates per diet). At the end of the feeding trial, the weight gain, feed intake, specific growth rate, and protein efficiency ratio of fish fed diets containing higher levels of myo-inositol (M800 & M1600) were significantly higher than those of fish fed the other diets (P<0.05). Feed conversion ratio, survival, hematocrits, and hemoglobin of fish fed experimental diets were not significantly different among all the fish groups. Whole body compositions of fish were not different except for lipid content. The lipid content was significantly different between M0 and M400 diet groups. These results indicate that juvenile olive flounder requires dietary supplementation of myo-inositol in diets for normal growth and its optimum level seems to be approximately 800 mg myo-inositol/kg diet.

• Korean Journal of Psychosomatic Medicine
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• v.9 no.1
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• pp.81-92
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• 2001

Stress has been linked to the pathophysiology and pathogenesis of various psychiatric illnesses. Over the past few years, our understanding of the brain and neuroendocrine systems that are linked to stress responses has increased enormously. This article reviews a series of animal and human studies to understand what are the central pathways by which stress is perceived, processed, and transduced into a neuroendocrine response. We focus on the limbic-hypothalamic-pituitary-adrenal(LHPA) axis and several neurotransmitter systems such as norepinephrine, CRF, serotonin, acetylcholine, and dopamine. LHPA stress circuit is a complex system with multiple control mechanisms which are altered in pathological states. CRF and related peptides in the central nervous system appear to enhance behavioral responses to stressors. Norepinephrine systems are also activated by stressors and cause the release of catecholamines from the autonomic nervous system. CRF-norepinephrine interaction makes a feed-forward system which may be important for an organism to mobilize not only the pituitary system but also the central nervous system, in response to environmental challenges. The interactions among several neurotransmitters and endocrine systems appear to play key roles in mediating various behavioral and psychological stress responses involving abnormal responses to stressors such as anxiety and affective disorders.

• The Korean Journal of Pesticide Science
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• v.15 no.3
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• pp.278-288
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• 2011

This study was conducted to evaluate the safety of ${\beta}$-carotene biofortified rice, a genetically modified organism (GMO) developed by Rural Development Administration. ${\beta}$-carotene biofortified rice were exposed on Sprague-Dawley rats for 13 weeks. All rats survived until the end of the exposure period. There were no biologically significant differences in body weight, feed and water consumption, weight gains and feed efficiency. There were no clinical signs of toxicity attributable to exposure to GM rice. Mild decreases in AST, ALT, TG levels were observed in Group II (25% GM rice (w/w) and Group III (50% GM rice (w/w), both in females and males. Results of histopathological changes treated with the ${\beta}$-carotene biofortified rice had no significant differences between the control and treatment groups. Based on these results, we deemed that genetically modified ${\beta}$-carotene biofortified rice was as safe as conventional rice.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.307-318
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• 2005

This study was conducted to examine effects of brewery meal-based fermented feedstuff supplemented with Aspergillus oryzae(AO) or Saccharomyces cerevisiae(SC) on luminal micro-organism of Korean native cattle. Two cows equipped with luminal cannulas were used as experimental animals. Experiment was done with three treatment groups: $71.5\%$ of commercial feed and $28.5\%$ of com silage(control): $45.0\%$ of commercial feed, $26.5\%$ of fermented feedstuff supplemented with AO and $28.5\%$ of corn silage(TAO): $45.0\%$ of commercial feed, $26.5\%$ of fermented ffedstuff supplemented with SC and $28.5\%$ of corn silage(TSC). The number of total viable bacteria (p<0.05), anaerobic fungi and protozoa(p<0.05) was higher in TAO and TSC than in control. The number of proteolytic bacteria(p<0.05), cellulolytic bacteria and xylan fermenters tended to be higher in TAO and TSC than in control. The dry matter recovery (DMR) of protozoa was higher in TAO and TSC than in control(p<0.05). The crude protein (CP) content of total microbes and protozoa was higher in TSC than in control and TAO (p<0.05). The CP content of bacteria was higher in TAO and TSC than in control(p<0.05). The ether extract(EE) content of the total microbes was higher in TAO than in control and TSC(p<0.05), and the EE of protozoa and bacteria were higher in TSC than in control and TAO(p<0.05). The ratio of essential amino acids of total microbe was higher in control than in TAO and TSC(p<0.05). The ratio of methionine and alanine of bacteria was higher in TAO and TSC than in control(p<0.05). The results suggested that the feeding of fermented feedstuff supplemented with AO or SC had an influence on the numbers of ruminal microorganism and the changes of microbial body composition.

• Korean Journal of Microbiology
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• v.41 no.3
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• pp.225-231
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• 2005

The characteristics of cell growth and medium-chain-length polyhydroxyalkanoate (MCL-PHA) biosynthesis of Pseudomonas chlororaphis HS21 were investigated using plant oils as the carbon substrate. The organism was efficiently capable of utilizing plant oils, such as palm oil, corn oil, and sunflower oil, as the sole carbon source for growth and MCL-PHA production. When palm oil (5 g/L) was used as the carbon source, the cell growth and MCL-PHA accumulation of this organism occurred simultaneously, and a high dry cell weight (2.4 g/L) and MCL-PHA ($40.2\;mol{\%}$ of dry cell weight) was achieved after 30 hr of batch-fermentation. The repeating unit in the MCL-PHA produced from palm oil composed of 3-hydroxyhexanoate ($7.0\;mol{\%}$), 3-hydroxyoctanoate ($45.3\;mol{\%}$), 3-hydroxydecanoate ($39.0\;mol{\%}$), 3-hydroxydodecanoate ($6.8\;mol{\%}$), and 3-hydroxytetradecanoate ($1.9\;mol{\%}$), as determined by GC/MS. Even though glucose was a carbon substrate that support cell growth but not PHA production, the conversion rate of palm oil to PHA was significantly increased when glucose was fed as a cosubstrate, suggesting that bioconversion of some functionalized carbon substrates to related polymers in P chlororaphis HS21 could be enhanced by the co-feed of good carbon substrates for cell growth. In addition, the change of compositions of repeating units in MCL-PHAs synthesized from the plant oils was markedly affected by the supplementation of acrylic acid, an inhibitor of fatty acid ${\beta}-oxidation$. The addition of acrylic acid resulted in the increase of longer chain-length repeating units, such as 3-hydroxydodecanoate and 3-hydroxytetradecanoate, in the MCL-PHAs produced. Particularly, MCI-PHAs containing high amounts of unsaturated repeating units could be produced when sunflower oil and corn oil were used as the carbon substrate. These results suggested that the alteration of PHA synthesis pathway by acrylic acid addition can offer the opportunity to design new functional MCL-PHAs and other unusual polyesters that have unique physico-chemical properties.