• Korean Journal of Plant Resources
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• v.19 no.1
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• pp.50-53
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• 2006

Nerine was originated from South Africa and around 30 kinds of species are distributed in worldwide. In present study we have characterized the condition of storage and growing conditions on the bulb propagation of Nerine by the tissue culture. Result indicated that the percentage of decrement, decay and sprouting of bulblets in the tissue culture was high at the higher temperature compare to lower temperature. The optimum conditions for storage and time were 12 weeks at $15^{\circ}C$ which were having 86.4% sprouting rate. The sprouting rate at different temperature and acclimation time, using bulblets in the tissue culture, were optimum at early June when temperature is relatively higher($22^{\circ}C$) that facilitate to breaking the dormancy. Growth characteristics and capacity of photosynthesis of Nerine were better at red and blue mixed lightness.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.423-427
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• 1992

During the cultivation of Penicillium verruculosum in the medium containing xylan as a sole carbon source for 26 days, xylanolytic activity and some changes were investigated. Protein content and xylanolytic activity, p-Nitrophenyl-$\beta$-D-xylopyranoside (PNPX), p-Nitrophenyl-$\beta$ -D-glucopyranoside (PNPG) hydrolytic activities were increased until 8 days but reducing sugar content was not correlated to protein content. When crude proteins from the culture broth were separated on SDS-PAGE, distribution of proteins was different from the culture broth of cellobiose octaacetate (COA) medium. The culture broth of xylan medium had high hydrolytic activity on xylan but not on cellulose. Furthermore, xylanolytic products were showed xylose, xylobiose and oligosaccharides on thin layer chromatography, and xylobiose was major product. Those result suggested that xylanolytic activity of culture broth was endo-type hydrolysis. Optimum temperatures of xylanolytic activity and PNPX hydrolytic activity of culture broth were 50~6$0^{\circ}C$ and 60~7$0^{\circ}C$, respectively and optimum pHs were 3.0~4.0 and 4.0~5.0, respectively.

• KSBB Journal
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• v.8 no.3
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• pp.193-199
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• 1993

To find out the optimum conditions for indigo cell culture in air-lift bioreactor, effects of media composition including nutrients and precursors of the indigo colorants on the cell growth and characteristics of the cell growth under various cultural conditions were analyzed. Optimum cultural conditions were tested and the growth characteristics were analyzed in external and internal loop type air-lift bioreactors during 14-day culture. Better cell growth was obtained when the inoculum size was higher in the range of 0.5∼2.5% packed cell volume tested. In the sucrose concentration of 2 to 4%, the cell growth was better when the sucrose concentration was 4% (w/w) in both types of reactors. Sucrose was used up in the early stage of exponential phase of growth At the optimum concentration of a Precursor tryptophan at 1 U UW was 3.8 g/l in internal loop bioreactor, and 3.5 g/l in external one after 14 days of cultivation. Addition of indole showed negative effect on cell growth of suspension culture in air-lift biorector culture and cell mass of 2.5 g/l and 2.2 g/l were obtained in external and internal loop bioreactor, respectively. Selected inorganic nitrogen source potassium nitrate showed about 110% increase in cell growth than that of control. DCW was 16.34 g/l under optimum conditions during 14-day cultivation in internal loop bioreactor.

• The Korean Journal of Food And Nutrition
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• v.11 no.6
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• pp.683-688
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• 1998

This study was conducted to develop optimal composition of flour brew in order to economically utilize flour brew inoculated by lactic acid bacteria as a starter(mother sponge) in bread-making. Two flour brews were prepared ; one with flour and water, the other with flour, water and NaCl. Various nutrients were added to both flour brews and Lactobacilli deMan Rogosa and Sharpe (MRS) broth to investigate the effect of them on growth and activities of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture in flour brews to be tested with incubation at 37$^{\circ}C$. The growth of Streptococcus thermophilus, Lactobacillus brevis and their mixed culture was stimulated by addition of NaCl with 0.85% concentratin and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation and more by mixed culture than by single lactic acid bacteria, resulting in 3 hrs reduction in cultivation time. the addition of 3% glucose to flour brew with NaCl was observed to enhance acid productioni by mixed culture. Yeast extract greatly affected growth and activities of mixed culture of lactic acid bacteria in flour brew with NaCl and its optimum level of this additive in flour brew with NaCl was approximately 1.0%. The optimal composition of flour brew for mixed culture of lactic acid bacteria was suggested as follows; flour 100g, water 300g, NaCl 3.46g, glucose 12.48g, yeast extract 3.46g.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.38 no.6
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• pp.393-398
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• 2005

Codium fragile is commercially farmed in Korea by natural blooming zygote attachment. Experiments found optimum conditions for artificial seed production and nursery culture of C. fragile by asexual reproduction. Isolated utricles and medullary filaments were regenerated to erect thalli using both indoor and outdoor culture experiments. Under the indoor culture conditions, irradiance was an important factor to control the development of erect thalli. Formation of erect thallus from the isolated medullary filaments in the indoor culture was induced after 30 days under $20^{\circ}C$ and $60{\mu}mol/m^2/sec$. The detachment of isolated utricles and medullary filaments from the substrates of seed strings was reduced by exposure to the air during 2 hrs before the indoor culture of seed strings. The maximum growth and development of erect thalli in the nursery culture was induced at a water depth of 0.5 m. Depending on the substrates of the seed strings the growth of erect thalli was not significantly different (p>0.05).

• The Korean Journal of Food And Nutrition
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• v.1 no.2
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• pp.31-36
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• 1988

An adaptive on-line optimization method has been applied to test the ability to maximize the cellular productivity of a continuous methylotroph culture system which was simulated by a variable yield Monod-type model. Optimum dilution rate and productivity were successively obtained and maintained at all times by the algorithm that utilizes steepest descent technique as optimization method and recursive least-square method with forgetting factor as dynamic model identification.

• Applied Biological Chemistry
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• v.18 no.3
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• pp.177-182
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• 1975

The analysis of Jerusalem artichoke showed that it contains 12.09% of Inulin. The results obtained from the examination of the conditions for fructose production by cultivating Pencillum sp 1 in the Jerusalem articoke medium were as follows: 1. The optimum amount of water added to Jerusalem artichoke was 2.5 $\ell$ of distilled water per ㎏ of fresh Jerusalem artichoke. It this case, the concentration of Inulin was 4% (w/v). 2. The optimum temperature was $30^{\circ}C$, the initial optimum pH was 5.0 and the optimum cultural period was 72 hours. 3. Shaking culture with 50 ml of the medium and 120 oscills/min in 500 ml shaking flask was most effective as the culture method. 4. 0.1% of $NH_4H_2PO_4$ as a nitrogen source, 0.001 of $FeSO_47H_20$ and 0.001% of $MgSO_47H_2$ as metal salts were most effective. 5. Fructose production continued to increase for 72 hours under the optimum conditions for cultivation and the highest production rate to the Inulin was 95.25%.

• Korean Journal of Food Science and Technology
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• v.38 no.2
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• pp.249-255
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• 2006

The optimum culture conditions for the ice nucleating activity and the cell growth of Xanthomonas translucens KCTC 2751 were investigated. The optimum initial pH and temperature for the cell growth and the ice nucleating activity were 6.5 and $25^{\circ}C$, respectively. The optimum culture medium for the ice nucleating activity was composed of 1.0% maltose, 1.4% yeast extract, 0.8% digested of gelatin, and 0.03% KCI in distilled water. Freezing operations carried out on distilled water showed that the degrees of supercooling were $-7.90^{\circ}C$ without ice nucleators, $-1.56^{\circ}C$ with silver iodide as a commercial ice nucleator, and $-1.36^{\circ}C$ when Xanthomonas translucens KCTC 2751 were added. During progressive freeze-concentration assays, the addition of Xanthomonas translucens KCTC 2751 led to lower saccharose concentrations in the crystals, while the cells led to higher saccharose concetrations in the concentrated phase.

• The Journal of the Convergence on Culture Technology
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• v.4 no.3
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• pp.213-220
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• 2018

The objective of this study was to estimate the optimum spacing of rail joint for a personal rapid transit(PRT) track system, and to compare the results with the normal rail and rail joint by performing the finite element analysis(FEA) and field measurements using actual vehicles. Based on the FEA and field measurement results compared, the optimum spacing of the rail joints was calculated to be maximum of 1.20m based on the rail displacement. The vertical displacement of the normal rail was higher than that of the rail joint at a spacing of 1.0m, but it was considered that the vehicle riding performance and serviceability of track would be improved in terms of the stability of the train due to similar to rail defection between normal rail and rail joint. Also, because of the proposed rail joint spacing in this study was longer than the current rail joint spacing, the economic effect would be expected by decreasing the amount of sleepers.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.356-360
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• 1988

The alkaline protease producing bacteria isolated from soil and identified as Bacillus subtilis. The optimum medium for alkaline protease production from the microorganism was as follows; soluble starch, 1.5% ; proteose peptone, 0.5% ; $K_2HPO_4$, 0.1% ; $MgSO_4{\cdot}7H_2O$, 0.02% and sodium carbonate, 1.0%. The optimum temperature for alkaline protease production was $35^{\circ}C$, and the initial pH of medium was pH 10.5. The alkaline protease activity was about 2,300 U per ml of culture broth by Casein-Folin Method. A 9.2 fold purification of alkaline protease was obtained from culture broth. The recovery was 14% and purified enzyme was identified as single band, and its molecular weight was about 19,000. The optimum temperature for enzyme reaction was $70^{\circ}C$, and optimum pH was 12. The activity of purified enzyme was inhibited by metal ion ($Fe^{++}$), and Phenylmethylsulfonyl Fluoride, a serine protease inhibitor.