• Applied Biological Chemistry
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• v.48 no.4
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• pp.425-430
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• 2005

[${\beta}-sitosterol$] is a plant sterol that reduces cholesterol levels and inhibits the growth of human prostate and colon cancer cells. Optimal conditions for ${\beta}-sitosterol$ production were examined from cell suspension cultures of Chrysanthemum coronarium L. The callus induction was optimal in MS medium containing 1 mg/l NAA and 1 mg/l BAP. Cell suspension culture was also established from the callus. Optimal ${\beta}-sitosterol$ production was obtained when the cells were cultured at an initial density of 2 mg DCW/l in MS medium containing 1 X sucrose (30 mg/l), 1 X nitrogen (1900 mg/l $KNO_3$, 1650 mg/l $NH_4NO_3$), and 1 X phosphate source (170 mg/l). In cell suspension cultures of C. coronarium L. using shake flasks, the peak content of ${\beta}-sitosterol$ was $150{\mu}g/g$ DCW. In cell suspension cultures of C. coronarium L. using an air-lift bioreactor, the maximum ${\beta}-sitosterol$ content of $143.8{\mu}g/g$ DCW was obtained at an air-flow rate of 100 cc/min.

• Korean Journal of Environmental Agriculture
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• v.12 no.2
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• pp.112-120
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• 1993

The use of fertilizer N is essential for maximum economic yield of crops. Meanwhile, enrichment of $NO_3^-$in the environment has to be avoided. Winter barley crop has a short duration of growth before winter, but is used to receive N greater than 60 kg/ha at seeding. Experiments were performed to determine the quantitative aspect of the fate of soil applied urea N among the residual, leached, and uptaken by winter barley (cv. Olbori), and to evaluate the effect of soil temperature on nitrification. Four levels of urea (0, 40, 80, and 120 kg N/ha) was basal-dressed to Olbori. $NH_4^+$ appeared dominant in the soil until 40 days after seeding, whereas $NO_3^-$ did thereafter. Nitrification rate at $5^{\circ}C$ of soil temperature was 40 to 50% of that at $15^{\circ}C. Linear increases in the number of ammonia oxidizing and nitrite oxidizing bacteria of the soil was present as the level of urea fertilization was higher. Less than 60% of N applied at seeding was uptaken by winter barley until mid-March but 50% was lost from death of older barley leaves during overwintering. Thereby only 10% of the applied N remained in the barley in spring. Only 15% of the applied N was present in the rhizosphere. The 17 to 20% of the soil applied N leached out as $NO_3^-$ the rhizosphere. Nitrogen leaching during winter was estimated to be 16 and 20 kg/ha when the basal application level of urea fertilization was 80 and 120 kg/ha, respectively.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.41-49
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• 2020

In this study, the effect of seed pre-treatments and pellet coating materials to enhance the efficiency of large-scale propagation of Aster koraiensis seeds were investigated. Seeds were immersed in water for one day, and only those that sank were used for pre-treatment to use filled seeds. Pre-treatments were divided into hormone treatments, with gibberellic acid (GA₃; 200 and 500 ppm) and 24-epibrassinolide (10^-6, 10^-7, and 10^-8M), and priming with potassium nitrate (100 mM of KNO₃). To produce pellet-coated seeds, pellet materials (DTCS or DTK) were applied to control (unprimed) and primed seeds with binders (PVA or CMC). The maximum germination percent (GP) of seeds before pellet coating was 65% (with the priming treatment), and there was no difference in the GP of seeds among hormone treatments. For seeds sown in a growth chamber on filter paper, GP was 41% for control (unprimed/uncoated) seeds, 65% for uncoated primed seeds, 71% for DTCS/PVA-pellet-coated seeds, and 42% for DTK/CMC-pellet-coated seeds. Seeds that were primed first and then pellet-coated showed greatly improved GP, mean germination time (MGT), and germination rate than seeds that were only pellet-coated. For seeds sown in commercial soil in a greenhouse, control seeds had a GP of 27%, whereas primed seeds had the highest GP (58%), and their MGT and GT were 9.4 days and 7.0%·day, respectively. In addition, DTK/PVA-pellet-coated seeds (40%) also had a GP higher than the control (27%), and their MGT was 15-27 days. For seeds sown in sandy-loam soil in a greenhouse, unprimed-pellet-coated seeds and primed-pellet-coated seeds both had GPs ranged of 39%, which were lower than that of control seeds. In general, the seeds that were pellet-coated with DTK had a higher GP than those pellet-coated with DTCS. Furthermore, the MGT of unprimed-pellet-coated seeds was 15.0-19.8 days, which was longer than the MGT of primed-pellet-coated seeds. These results suggest that priming enhances seedling emergence of Aster koraiensis seeds. Moreover, when priming is combined with pellet coating, DTK is a more suitable pellet material than DTCS, and PVA and CMC are equally suitable adhesives.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.747-756
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• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.7 no.3
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• pp.105-114
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• 1974

Identification and change of microflora during the fermentation of anchovy Engraulis japonica, under the halophilic circumstance were investigated. The change of salinity and pH in meat and juice which decide the environment for microorganism and decomposition of nitrogenous compound which functions as a nutrient source were also discussed by measuring the content of total-N, amino-N, nonprotein-N, TMA and VBN, The fresh anchovy was mixed with rock salt (20 percent w/w) and stocked for six months. Through the fermentation lag phase of viable cells extended for 20 days that was obviously larger compared with other circumstances, hereafter increased to reach the maximum value of $5\times10^4$ total count per gram at 35 day stock. The stationary phase proceeded for 25 days. 540 strains were isolated and among them 11 genus of bacteria, 3 genus of yeasts, were identified and other 2 yeast strains of unidentified. At the initial stage of fermentation, Pseudomonas, and Helobacterium prevalently grew, at the middle stage, they disappeared rapidly and Pediococcus and yeasts completely dominated, where they are assumed to get directly involved with fermentation of fish, The PH value tended to decrease in the progress of fermentation and at 100 day stock it showed the minimum value of 5.5 to 5.6 in both meat and juice. The highest salinity of meat decreased to 18 percent, while in juice it decreased to 28 percent since 50 days stock. The content of total-N in meat gradually decreased to 2.8 percent, while in juice it increased to 2.3 percent at 100 day stock, However nonprotein-N was 1.8 percent and amino-N was 1.1 Percent. Since 100 days stock, the increasing rate of amino-M is too low it could be judged to entered the final stage of fermentation, In the first 20 days stock, the increase of VBN and TMA can be explained by the growth of putrefactive bacteria such as pseudomonas on the meat before salts penetrate into the fish meat, while reincrement after 100 days stock, is explained by decomposition of free amino acid due to the reactions of bacteria and enzymes.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.65-72
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• 2001

Four newly isolated bacteria from soil were used to manufacture microbial inoculum to compost food waste. The bacteria, GM103, V25, V31, and V35, were identified as Bacillus licheniformis, B. subtilis, B. stearothermophilius, and B, subtilis, respectively. The bacterial strains were efficient to degrade protein and starch and also able to inhibit the growth of plant pathogenic fungus Rhizopus stronifer. The GM103 showed distinct capability in degrading starch, but grow only aerobically. The other three bacterial strains. V25, V31, and V35, could grow both aerobically as well as anaerobically, in 10%(w/v) salt, at $50^{\circ}C$, and had good viability and survival rate in soil. These characteristics of the bacterial strains are very adquate in Korean food composting containing high concentration of salt, especially at home. By mixing the 4 bacterial culture broth with molasses, beet pulp, zeolite, The bacterial inoculum for food waste composting-BIOTOP-CLEAN-was made. The performance of food waste composting by the BIOTOP-CLEAN was compared with that by control(not treated) and HS(other demestic company's inoculum product for food waste composting). The maximum temperature of the food waste during the composting with the BIOTOP-CLEAN was $50^{\circ}C$, while those of the control and HS were $30^{\circ}C$ and $35^{\circ}C$, respectively. The BIOTOP-CLEAN gave the good smell and showed dark brown color, while the control gave bad smell and HS gave less bad smell. These indicates that the food waste composting by the BIOTOP-CLEAN had been well accomplished. The culture broth of V25, V31, V35 were sparyed to the plants of tomato, chinese cabbage, raddish, red pepper every month and the spraying the culture broth to these plant significantly improved the production yield of the crops, due to the control effect of the bacterial strains against the plant pathogens.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.459-467
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• 2020

In this study, we investigated the changes in both ambient temperature and microbial contamination of fresh convenience foods (FCFs) caused by the behavior of consumers after purchase. According to consumer survey results, it took 0.5 to 3 h put the purchased FCF in a home refrigerator or consume it. Only aerobic bacteria and Staphylococcus aureus (below maximum permitted limit) were detected in FCFs obtained from a local market. During storage of FCFs in a vehicle trunk for up to 3 h. the external and internal temperatures of FCFs were found to be 19 and 18.5℃ in spring, 44 and 42℃ in summer, 31.3 and 29.2℃ in autumn, and 17.6 and 16.8℃ in winter, respectively. Changes in contamination levels of aerobic bacteria on FCFs stored in a vehicle trunk for up to 3 hours are as follows: 2.72 → 3.41 log CFU/g in spring, 3.11 → 4.32 log CFU/g in summer, 3.08 → 3.81 log CFU/g in autumn, 2.71 → 3.36 log CFU/g in winter. S. aureus exceeding the tolerance was detected even when the FCFs were stored in a vehicle trunk for 1 h in summer and autumn and 2 h in spring and winter. Among three boxes (corrugated box, styrofoam box, and corrugated box coated with an aluminum film), the styrofoam box maintained the lowest temperature and showed the lowest growth rate of microorganisms on FCF after storage for 3 h in the vehicle trunk depending on whether ice was added. These results indicated that the possibility of food poisoning occurs when FCFs are exposed to the external environment. It is necessary to provide guidelines regarding storage temperature and allowable time for safe consumption of FCFs after purchase.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.174-187
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• 2008

In an effort to identify structure and function of microbial loop in Paldang reservoir, we monitored environmental and biological factors at Kyungan stream (station K), Paldang dam (station P) and the confluence of North and South Han River (station M) from March to December, 2005. DOC concentration was higher in March to May and November than the others. Nutrient concentration in station K detected relatively higher than that of two stations. Both of phosphate and silicate gradually increased at all stations until September, after then decreased. The highest Chl-$\alpha$ concentration was observed at all stations in April, and November. The carbon biomass of bacteria and HNF were relatively higher in March, May and August than the others, whereas that of the ciliate showed no significant difference in monthly fluctuation. Nevertheless, the significant relationships revealed between ciliate (P<0.001) and HNF (P<0.05) and bacterial density. Tintinnopsis cratera, Didinium sp., Vorticella sp., Paramecium sp. and Strombidium sp. were dominant species in ciliate community. The dominant species of phytoplankton were Stephanodiscus hantzschii and Cyclotella meneghiniana at almost stations in Spring, Summer and Autumn. However, Aulacoseira granulata accounted for >95% of phytoplankton biomass at station P and M in Autumn. The carbon biomass of zooplankton was highest at station P and M in June, and relatively higher biomass observed at all stations in August, October and November. Diaphanosoma brachyurum and Bosmina longirostris were dominant in stations P and M of June and in all stations of October and November, respectively. The maximum growth (A. granulata: $0.17\;d^{-1}$, S. hantzschii: $0.14\;d^{-1}$) and grazing rate (A. granulata: 1.93 preys $d^{-1}$, S. hantzschii: 1.63 preys $d^{-1}$) of Bosmina longirostris revealed in algal preys as Aulacoseira granulata and Stephanodiscus hantzschii. In conclusion, these results suggest that bacteria and phytoplankton can play the most crucial source as prey within microbial food chain in Spring and Summer and grazing food chain in Autumn, respectively.

• Korean Journal of Food Science and Technology
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• v.14 no.1
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• pp.72-79
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• 1982

Several mutants were isolated from the parent strain of Aspergillus niger CF: the first mutant strain CF-11 was obtained by UV irradiation, and the second mutant strain CF-21 and CF-22 were from NTG (N-methyl-N'-nitroso-N-nitroso-guanidine) treatment on the CF-11. These mutants were characterized, and their enzyme and acid production on wheat bran Koji and wheat flour Koji were studied. Asp. niger CF-22 mutant appeared to be tan type which conidial heads were discolored. It's glucoamylase activity was inreased approximately two times and its ${\alpha}-amylase$ about 50 percent as compared with that of the parent strain of Asp. niger CF, when grown on wheat bran Koji under the optimal conditions. Asp. niger CF-21 mutant showed slower growth rate and poor sporulation than the wild type, although its conidial heads were not discolored. Approximately 4-fold increment in its acid production was observed as compared with the weld type. The activities of glucoamylase and ${\alpha}-amylase$ of the Asp. niger CF-22 and CF-21 mutants were higher than those of the wild type, but their protease activity was rather lower. The maximum production of glucoamylase by the Asp. niger CF-22 mutant was obtained after 2 to 3 days incubation on wheat bran at 30 to $35^{\circ}C;$ ${\alpha}-amylase$2 days incubation at 30 to $35^{\circ}C$. The maximal levels of acid production by the mutant CF-21 was appeared after 2 days incubation on wheat bran Koji, and after 3 days on wheat flour Koji at $30^{\circ}C$. Little differences in the levels of acid production were observed between on wheat bran and flour Koji.

• Journal of Plant Biotechnology
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• v.40 no.2
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• pp.79-87
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• 2013

The aim of this study was to establish plant regeneration from leaf explants of Sedum tosaense Makino, which is globally rare and endangered species. The leaf explants of S. tosaense were cultured on the MS medium supplemented with different concentration of BA and NAA for callus induction. Callus induction was showed the highest (100%) on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA. The highest number of shoots were regenerated when callus were cultured on MS medium containing $2.0mg{\cdot}L^{-1}$ BA and $1.0mg{\cdot}L^{-1}$ NAA for 5 weeks. The axillary bud were cultured on the MS media supplemented with combination of BA and NAA for in vitro propagation. The highest number of adventitious shoot (7.9 per explants) formed at $1.0mg{\cdot}L^{-1}$ NAA and $2.0mg{\cdot}L^{-1}$ BA. For rooting, MS medium supplemented with or without $2.0g{\cdot}L^{-1}$ activated charcoal was tested. The optimal results were observed using MS medium supplemented with $2.0g{\cdot}L^{-1}$ activated charcoal, on which 85.7 (No. of root), 4.6 cm (length of root). 1,200 ppm $CO_2$ and 350 ppm $CO_2$ were supplied for make certain the effects of $CO_2$ on pre-acclimatization by photoautotrophic culture. 1,200 ppm $CO_2$ treatment was established higher than 350 ppm $CO_2$ treatment. Soil acclimatization of in vitro plantlets was the best in mixture soil consisted of peat moss and perlite with 100% survival rate and they showed the maximum growth.