• 한국양식학회지
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• 제18권2호
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• pp.115-121
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• 2005

본 연구는 통기방법과 배양수의 환수에 따른 담수산 rotifer B. calyciflorus의 내구란 형성을 조사하였고 0.5 톤 수조에서 내구란 대량 생산을 수행하였다. 산소와 공기를 공급한 실험구에 있어서 rotifer의 최고밀도와 유성생식률은 차이는 없으나 수정률과 내구란 형성은 공기를 공급한 실험구가 산소를 공급한 실험구보다 높게 나타났다. 배양수의 환수간격에 따른 실험에서 환수를 하지 않은 실험구가 rotifer 최고밀도와 내구란 형성은 환수를 한 실험구(매일 환수한 실험구)보다 높게 나타났지만 내구란 생산의 효율적인 측면에서 Chlorella 건조중량당 내구란 형성은 환수를 한 실험구(매일 환수한 실험구)에서 가장 높게 나타났다. 또한 0.5톤 수조에서 내구란의 총 생산량은 $51.8{\sim}57.9{\times}10^6$개로 나타났다. 본 연구의 결과를 종합하여 볼 때, 공기를 공급한 batch 배양이 담수산 rotifer, B. calyciforus의 내구란을 대량생산하는데 효과적인 방법인 것으로 판단된다. 또한 이종의 내구란 대량생산은 해수산 rotifer B. plicatilis와 B. rotundiformis와 비슷한 생산 효율을 보인 것으로 판단된다.

• 한국물환경학회지
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• 제21권2호
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• pp.118-124
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• 2005

The oxygen solubilized device(O.S.D) and standardized microorganism culture system is more efficient than physical and chemical purification techniques in closed water. This study was to determine how the O.S.D and standardized culture system is efficient in purification capacity in closed water based on the lab scale and pilot plant. In the batch test, inducing the quantitative results from pilot plant operation condition, removal efficiency of COD and TN were about 48.3% and 35% respectively, while SS and chlorophyll-a were 94.9% and 68.7%. The pilot plant results showed that suspended solid(SS) and chlorophyll-a removal efficiency were 60% and 59% respectively, due to coagulation characteristics by standardized culture. Total nitrogen(TN) and total phosphorus(TP)showed good effect for the purification of target pond water quality from field data. Additionally, released velocity was determined in control condition of $5.31mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $2486.8mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. Otherwise, phosphate and COD reflux in the aeration and microorganism condition was showed $-9.95mgPO{_4}^{3-}{\cdot}m^{-2}{\cdot}day^{-1}$ and $-397.88mgCOD{\cdot}m^{-2}{\cdot}day^{-1}$. This technology is the most effective not only removal of SS and chlorophyll-a but also control of phosphate and COD release which is very important phenomena in evaluating water quality in closed water like a reservoir and pond.

• Journal of Biosystems Engineering
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• 제15권4호
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• pp.328-338
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• 1990

The objective of this study was to develop automatic systems of nutrient solution management for optimal nutrient solution environment and labor saving in water culture which enables factory crop production. In this study, an automatic control system and its driving program are developed to prepare, supply, and recover nutrient solution and to keep the optimal solution concentration level using microcomputers. Based on this study, the following conclusions are obtained: 1. The concentration measured by the system using oscillating circuit designed and built in this study, gave good agreements with the actual nutrient solution. 2. In water culture, the period of 12 hours for measuring concentration, pH, and temperature of the nutrient solution was optimum. Addition of control solution due to the decrease of the nutrient solution concentration is required in every 3 to 5 days. 3. It is estimated that the period of the whole solution change is 15 days, however, further research is needed to assure it. In addition, this period must be shortened in the future. 4. Both the hardware and software of the developed optimal nutrient solution control system in the water culture are working very well, however, it is necessary to develop a more economical one-chip micro controller to substitute for the microcomputer.

• 한국양식학회지
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• 제6권4호
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• pp.311-321
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• 1993

Ammonia accumulation is regarded as the limiting factor of the first priority in water qualities of aquatic culture systems. Nitrification efficiency and characteristics in seawater were evaluated using Rotating Biological Contactor (RBC) process as a part of the recycling water treatment facilities for marine fish culture system. Ammonia removal efficiency regarded 99.7 to $83.7\%$ at the ammonia surface loading rates of 48 to $393 mg/m^2$ -day. RBC process was able to withstand to the fluctuation of influent ammonia concentrations and loading and produced the stable effluent. The mathematical model on the fixed-film biological reactor developed by Kornegay seemed to be suitable to RBC process kinetic evaluation for the recycling water treatment of the marine fish culture system. Area capacity constant (P) and half-velocity constant (Ks) in the model were 0.188g/m^2$-day and 1.25mg/l, respectively.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.80-84
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• 2005

The water requirement of transplanting culture(TC) consisting of 16 plots and direct seeding culture in a well-drained paddy field(DC) also having 15 plots were measured in order to clarify the influence factors on water requirement. Each plot was maintained under different cultivation conditions. Those varied cultivation conditions were classified into 7 items. Subsequently, the relationship between water requirement and 7 items were analyzed by evaluating the average water requirement in each condition to clarify the items influencing water requirement. From the analysis of the results, the water requirement of DC was determined to be 3.5 times of the TC. Furthermore, water requirement in DC and TC were influenced mainly by ponding depth and locational condition respectively.

• 한국식생활문화학회지
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• 제12권4호
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• pp.419-421
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• 1997

Washing water volume of rice for cooking and rice weight for one person per meal in one household were surveyed for confirming pollution by the washing water and total losses by rice washing procedures. The mean size of a family was 4.64 persons and the mean consumption weight of rice per capital per meal was 138.43g. It is used 0.782 L of water for washing the rice per capital share. The washing water of rice was composed of 0.32% of total solid, 0.11% of soluble solid and 1.65% of solid loss to rice, and COD and BOD of it were 2.400 and 3.564 ppm respectively. Based on total population in Korea, 41 miliion, excepting age below 4, total cost for washing water of rice summed up about 1,495 billion won including 8.8 billion won for tap water cost, 11.7 billion won for waste water treatment, and 129 billion for solid loss of rice.

• Journal of Microbiology and Biotechnology
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• 제24권5호
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• pp.629-638
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• 2014

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at $50^{\circ}C$ for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

• 한국미생물·생명공학회지
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• 제27권1호
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• pp.46-53
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• 1999

The purpose of this study was to optimize the conditions of continuous mixed culture of C.butyricum and R. spaeroides K-7, which were able to produce hydrogen using biomass-dreived substrate. To investigate the possibility of continuous culture, semi-continuous culture was carried out for 20 days. In semi-continuous culture using the reactor system, the replacement rate of fresh medium was 30% of total medium volume for the highest hydrogen evolution. In continuous culture, the optimum dilution rate was determined to be 0.05$h^{-1}$. The continuous culture produced 3.1 times as compared with the hydrogen on batch culture. On the other hand, the continuous mixed culture produced 1.3~2.1 times as much as hydrogen of the continuous monoculture of C. butyricum. When 10g of glucose in the media (1l) was supplied as a carbon source on continuous culture, mixed culture of C. butyricum and R. sphaeroides K-7 increased hydrogen evolution rate. Because considerable amount of glutamate was contained in waste water of glutamate fermentation, utilization of glutamate was examined in mixed culture. As a result of examination, production of hydorgen was slightly inhibited by high concentration of glutamate, more than 20mM, on continuous monoculture of R. sphaeroides K-7. On the other hand, both on continuous monoculture of C. butyricum and on mixed culture of C. butyricum and R. sphaeroides K-7, production of hydrogen was not inhibited by high concentration of glutamate such as 100mM. Hence this suggests that high concentration of waste water can be used as good substrate for hydrogen production on monoculture of C. butyricum and mixed culture of C. butyricum and R. sphaeroides K-7.

• Toxicological Research
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• 제14권3호
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• pp.301-306
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• 1998

This experiment was carrid out to know the effects of heating and serum on hydroxyl radicals in embryonic mouse forebrain (cerebrum) culture. The heating to mouse embryonic cerebrum cells in culture was done in a water bath at 43${\circ}C$ for 60min. After that, two supernatants were prepared at 20 hrs and 48 hrs respectively after heat treatment to the brain cells. To find out the heating effects on neuron cells, mouse cerebrum cells (13 embryonic day) were cultured in hydroxyl radical generation system composed of 20mU/ml glucose oxidase (GO system), using condition of normal culture media (MEM, 5% serum, 5% $CO_2$or supernatant prepared after heating at 43${\circ}C$ for 60 min in a water bath. Supernatant prepared at 20 hrs after heat treatment had a greater protective effects against hydroxyl radical than supernatant prepared at 48 hrs after heat treatment . Otherwise, the protective effect of serum against hydroxyl radicals in the cultured brain cells is higher than that in the heat treatment. These results indicated that serum in culture media reduced cytotoxicity of hydroxyl radicals in mouse forebrain culture, also that heat treatment showed the protective effects against hydroxyl radicals generated with 20mU/ml GO system in mouse forebrain culture.

• 수산경영론집
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• 제42권2호
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• pp.85-96
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• 2011

Oliver flounder population density affect Oliver flounder growth and mortality rate. In laboratory pilot experiment, Oliver flounder growth rate is inversely proportional to stocking density. But previous study has not proved external validity. This study is aimed to analyze the effect of stocking density on the Oliver flounder culture farms in Jeju Island. In order to do this, I selected 13 farms in Jeju island as a sample. In the study, various analytical methods including productivity analysis, regression analysis, statistical analysis were conducted for 13 Oliver flounder culture farms. The result of analysis can be summarized as follows. First, in case of the Oliver flounder culture farms, Bertalanffy equation is not applicable to the Oliver flounder growth. Second, the Oliver flounder stocking density, defined as the surface area of Oliver flounder per $m^2$ of water surface area, is preferred to density definition defined as the weight of Oliver flounder per $m^2$ of water surface area on the Oliver Flounder Culture Farms case. Third, growth rate and production weight on the Oliver flounder culture farms are inversely proportional to stocking density on spearman rank correlation test. When extensive comparable biological and culture condition data become available, analysis model can be easily modified to yield more accurate results.