• YAKHAK HOEJI
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• v.47 no.2
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• pp.93-97
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• 2003

Kombucha fermentation broth has been used as a popular health beverage and an alternative therapy with prophylactic and therapeutic benefit. We tried to establish optimal culture conditions for Kombucha fermentation in milk and to investigate cytotoxicity and antioxidative enzyme activity of Kombucha broth against normal human fibroblasts. The optimal conditions of Kombuch culture were established to 3$0^{\circ}C$, 20∼23 hours by DPPH radical scavenging test. There were positive effects on cell growth while no cytotoxicity against primary normal human diploid fibroblasts was found. The activites of glutathione peroxide and catalase in the cells treated by hydrogen peroxide (1 mM) alone and by hydrogen peroxide with Kombucha broth (1 mg/mι) were significantly different (p＜0.05). These results suggest that Kombucha broth could be developed as an antioxidant agent for a new cosmetic material.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.5
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• pp.408-413
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• 2006

We assessed the ability of a Pseudonocardia sp. from soil samples to bioconvert vitamin $D_3$. The optimal culture conditions for the bioconversion of vitamin $D_3$ to active $1{\alpha}$,25-dihydroxyvitamin $D_3$ were investigated by varying the carbon and nitrogen sources, the metal salt concentrations, the initial pH, and the temperature. Microbial transformations were carried out with the addition of vitamin $D_3$ dissolved in ethanol. They were sampled by extraction with methanol-dichloromethane and the samples were examined by HPLC. Optimum culture conditions were found to be 0.4% yeast extract, 1% glucose, 3% starch, 1% fish meal, 0.2% NaCl, 0.01% $K_2HPO_4$, 0.2% $CaCO_3$, 0.01% NaF, and pH 7.0 at $28^{\circ}C$. The optimal timing of the addition of vitamin $D_3$ for the production of calcitriol by Pseudonocardia autotrophica ID9302 was concurrent with the inoculation of seed culture broth. Maximum calcitriol productivity and the yield of bioconversion reached a value of 10.4mg/L and 10.4% respectively on the 7th day in a 75L fementer jar under the above conditions.

• Journal of Environmental Science International
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• v.32 no.3
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• pp.173-179
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• 2023

Rats are one of the most widely used animals in biomedical sciences because their metabolism and physiology are comparable to humans. In recent years, gene-targeted models have been developed using various animal species utilizing engineered nucleases such as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated gene (Cas). It has recently become possible to efficiently transfect CRISPR/Cas into embryos via electroporation. However, electroporation can damage fertilized eggs; therefore, it is important to determine the optimal embryo culture conditions. A standardized approach for routine and reproducible rat transgenesis will render rat models more accessible for research. We performed experiments to obtain rat embryos with efficient superovulation and synchronization, and to investigate the appropriate medium conditions for pronuclear stage embryos subjected to electroporation stimulation for the introduction of engineered nuclease.

• Journal of Embryo Transfer
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• v.15 no.3
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• pp.271-277
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• 2000

This study was conducted to establish the optimal culture conditions for in vitro production of bovine embryos derived from slaughter house ovaries. Cumulus-oocyte- complexes (COCs) collected by aspiration from follicles of 2~7 mm in diameter were matured in Ham's F-10 medium supplemented with 0.01 $\mu\textrm{g}$/m1 epidermal growth factor (EGF) at 39$^{\circ}C$ in a humidified atmosphere of 5% $CO_2$in air. After 24 hrs of culture, the oocytes were co-cultured with epididymal sperm selected off by Percoll-density gradient in TALP medium for 24 hrs. The presumptive zygotes were cultured in HECM-6 medium for 3 d post-insemination, and followed by cultured in TCM199 medium until 7 to 10d post-insemination. The cultures were compared of their cleavage and development into later stage in culture medium by additions of different protein sources (PVA, BSA and BCS) and by different embryo density. The rates of cleavage and development rates into blastocyst were not significantly (P<0.05) different among the culture media containing with BSA (75.0% and 40.5%), BCS (76.7% and 38.0%) and PVA (72.5% and 42.2%), respectively. Significantly (P<0.05) higher blastocysts rates were obtained in culturing of 30 and 40 embryos in each 50$\mu$l droplets of culture medium than in 5, 10 and 20 embryos. These results indicate that the optimal density of embryos is 30~40 embryos in a 50$\mu$l droplet of culture medium. Furthermore there is no effect of different protein sources on early embryonic development.

• Journal of Life Science
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• v.14 no.1
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• pp.126-130
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• 2004

This study was carred out to get the basic conditions for the mycelial growth of Morchella esculenta in shaking flask culture. The optimal temperature and initial pH of mycelial growth of Morchella escuzenta were 25$\pm$1$^{\circ}C$ and 6.5, respectively. The optimal medium was BG medium. Among the carbon sources tested, fructose was favorable for the mycelial growth and optimal fructose concentration was 5.0% (w/v). As nitrogen sources, peptone and NH$_4$Cl appeared to be favorable and optimal concentration was 4.0% [(w/v), ratio of 1:1].

• Microbiology and Biotechnology Letters
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• v.23 no.3
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• pp.263-268
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• 1995

A screening was performed to isolate exoploysaccharide-producing microorganisms, which synthesized specific exopolysaccharide for the substitutive of commercial polysaccharides, from natural sources. Soil bacterium, one of 378 mucoid isolates, was finally selected as potential producer of polysaccharides which made the culture broth very viscous and thus examined in detail for optimal medium composition. Isolated strain was identified as Xanthomonas sp. EPS- 1 from the results of morphological and biochemical characteristics. The composition of optimal medium for exopolysaccharide production was as follows: 50 g sucrose, 1.5 g peptone, 2 g KH$_{2}$PO$_{4}$, 2 g MgSO$_{4}$, -7H$_{2}$O, 3 g NaCl, 0.05 g CaCO$_{3}$, 0.07 g FeSO$_{4}$-7H$_{2}$O and 0.05 g MnSO$_{4}$-7H$_{2}$O in 1 liter of distilled water. From the experiments of temperature and pH dependence, the optimal conditions for exopolysaccharide biosynthesis seemed to be 30$\circ$C and 8.0, respectively. About 14.9 gram of maximum exopolysaccharide per liter was obtained at the initial pH 8.0, 30$\circ$C and 250 rpm in a flask culture. The exopolysaccharide EPS-1 had such potential as an emulsifying agent and a gelling agent in comparision with commercial exopolysaccharide.

• KSBB Journal
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• v.14 no.5
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• pp.572-577
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• 1999

A marine bacterium with highly effective agar degrading activity was ioslated from the southern sea of Korea (Chonnam, YoChon) and identified as Cytophaga sp. and named as Cytophaga sp. AYK301. This strain produced an extracellular agarase which had a high activity with agar. The optimum culture conditions for the production of agarase have been determined. For the increase of agarase productivity, 0.2% agar, 0.3% beef extract, and 0.05% NH$_4$NO$_3$ were used as carbon, organic and inorganic nitrogen source, respectively. The optimal initial pH, NaCl, culture time and temperature for the agar degrading activity were 7.5, 7.0%, 36 hr and $25^{\circ}C$, respectively. In the optimal conditions, the agarase production was increased up to more than 4.0 folds as compared to that by the basal medium.

• The Korean Journal of Mycology
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• v.48 no.3
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• pp.273-284
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• 2020

Calocybe indica is an edible mushroom commercially cultivated in India and other tropical countries. In this study, the culture characteristics and optimal conditions of milky mushroom strains were determined. The growth temperature and pH range of milky mushrooms was extensively investigated between 15-35 ℃ and pH 3-11. For efficient cultivation, 20 types of nutrient sources were selected that consisted of one of 21 types of carbon sources, 6 organic nitrogen sources, 6 inorganic nitrogen sources, 13 amino acids, 6 organic acids and 12 inorganic salts. The impact of each of the selected nutrition sources and their concentration on growth was investigated. The optimum pH and temperature were determined to be pH 6.0 and 15 ℃, respectively. The optimum concentration of medium elements for the mycelial growth of C. indica was determined to be as follows: carbon source, 2% maltose; organic nitrogen source, 1% yeast extract; inorganic nitrogen source, 0.1% NaNO₃; amino acid, 0.7% asparagine; organic acid, 0.07% acetic acid; inorganic salt, 0.07 mM MnSO₄.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.130-134
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• 2005

Isolation of a pigment overproducing mutant, P-57, by ultraviolet irradiation of Monascus purpureus KCCM 60016 and investigation of the optimal conditions for pigment production of the mutant were carried out. P-57 mutant produced pigment on solid state culture. Unpolished rice was the best cereal source for pigment production among eight kinds of tested cereal sources for the solid culture of the mutant. The optimal culture condition for pigment production were obtained from the cultivated at $30^{\circ}C,\;90\%$ humidity for 30 days. The P-57 mutant strain showed the best pigment productivity of 160.0 unit at red pigment, 193.6 unit at orange pigment, and 141.6 unit at yellow pigment on solid state culture under optimal condition.

• Mycobiology
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• v.38 no.3
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• pp.195-202
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• 2010

Coriolus versicolor, is one of the most popular medicinal mushrooms due its various biologically active components. This study was conducted to obtain basic information regarding the mycelial culture conditions of C. versicolor. Based on the culture, and MCM media were suitable for the mycelial growth of the mushroom. The optimum carbon and nitrogen sources were dextrin and yeast extract, respectively, and the optimum C/N ratio was 10 to 2 when 2% glucose was used. Other minor components required for optimal growth included thiamine-HCl and biotin as vitamins, succinic acid, lactic acid and citric acid as organic acids, as well as $MgSO_4{\cdot}7H_2O$ as mineral salts.