• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.215-222
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• 1999

Platycodon root contains abundant pharmaceutical substances and is widely used as a food and a medicinal herb. This study was conducted to determine the cultural environment and soil morphological characteristics of platycodon. Sampling sites were Keochang 4, Kimhae 7, Haman 6, Chinju 6 and Koseong 3 fields in Kyongnam province and Hongcheong 6 fields in Kangwon province. The average continious cropping year was highest Chinju 8.0-years old, whereas lowest Hongcheon 2.3-years old. The average cropping area and compost application were highest Hongcheon 1.3ha and $108Mg\;ha^{-1}$ respectively than other areas. The slope was in order to Koseong steep slope with 35%. Koechang 28%, Flaman 16%, Chinju 11.7%, Kimhae 11% and Hongcheon 7.5%. The drainage classes was well drained in Koechang. Kimhae, Chinju and Koseong, while it s poorly drained in Hongcheon and Haman. Distribution of topography was highest rolling 37.9% and drainage classes was highest well drained 48.3%. The root disease incidence rate was in the order of Haman 56.8%, Hongcheon 52.5%, Kimhae 36.7%, Koechang 35.3%, Chinju 32.3% and Koseong 30.0%. The yield at the Chinju $36.17Mg\;ha^{-1}$ was higher than that of Koseong $25.00Mg\;ha^{-1}$, Kimhae $13.57Mg\;ha^{-1}$, Koechang $11.75Mg\;ha^{-1}$, Haman $9.50Mg\;ha^{-1}$ and Hongcheon $5.24Mg\;ha^{-1}$. The average temperature was correlated with the disease incidence rate by $Y=3.07X^2-87.16X+649.26(R^2=0.947^{**})$ and yield by $Y=-478.68X^2+13403X-90836(R^2=0.763^*)$. The root disease incidence rate was correlated with drainage classes Y=19.1X-5.26($R^2=0.592{***}$), topography Y=9.68X+10.77($R^2=0.205^{**}$) and slope Y=0.85X+-27.88 ($R^2=0.143^*$). The yield was correlated with drainage classes Y=-10X+42($R^2=0.348^{**}$), topography Y=-5.34X+34.5 ($R^2=0.134^*$) and slope Y=-0.68X+25.48($R^2=0.129^*$). The optimum cultivated land of perennial platycodon was average temperature $14^{\circ}C$, direction of southeast, topography of flat or undulating, slope of 0-6%, well drained.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.260-266
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• 1981

Some properties of cellulase and xylanase produced from Pleurotus ostreatus 301 and Lentinus edodes 3-1 during its growth in rice straw medium were investigated. The cellulase activities of P. ostreatus 301 and L. edodes 3-1 were increased in proportion to substrate concentration within 0.6% and 0.8%, respectively, and xylanase activities of two strains were increased within 1%. The reducing sugar production of cellulase and xylanase in two strains were proportionaly increased until 30 min. and 60 min. respectively. The opium pH for cellulase activities of P. ostreatus 301 and L. edodes 3-1 were pH 4.0 and pH 4.5, respectively, and xylanase activities of two strains were pH 5.0. The stable pH range for cellulase activities of P. ostreatus 301 was within 4.0 to 6.0 and L. edodes 3-1 was within 3.0 to 5.0, Xylanase activities of P. ostreatus 301 was within 4.5 to 6.0 and L. edodes 3-1 was within 3.5 to 6.0. The optium temperature for cellulase activities of P. ostraeatus 301 and L. edodes 3-1 were $40^{\circ}C$ and $50^{\circ}C$, respectively, but xylanase activities of P. ostreatus 301 and L. edodes 3-1 were $50^{\circ}C$ and $45^{\circ}C$, respectively. Thermal stability of enzymes were below of optimum temperature and these were mostly inactivate at $70^{\circ}C$ for 10 min of the metalic ions tested, cellulase activities of L. edodes 3-1 was increased by $Co^{++},\; Mg^{++}$ at the concentration of $10^{-2}M$, but were greatly inhibited by $Hg^{++},\;Cu^{++}$ in two strains. Xylanase activities were increased by $Ca^{++},\;Co^{++},\;Mg^{++}$ and $Cd^{++}$ but was greatly inhibited by $Hg^{++}$.

• Journal of Mushroom
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• v.14 no.4
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• pp.202-206
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• 2016

Oyster mushrooms are widely cultivated and consumed in Korea. P. ostreatus 'Suhan(ASI 2504)' is an ideal cultivar for mushroom farmers due to its dark pileus and thick stipe; however, as it is very sensitive to environmental conditions, an alternative cultivar is required. To develop a new cultivar, parental strains 'Suhan(ASI 2504)' and 'ASI 0665 (Heuktari)' were selected from various collected strains according to morphological characteristics. P. ostreatus 'Soltari' was developed by DiMon crossing between the dikaryotic strain 'Suhan' and the monokaryotic strain derived from 'Heuktari'. Thirty-eight of the 100 crossed strains were selected following analysis of mitochondrial genetic characteristics, and 'Soltari' was ultimately selected by continuous cultivation tests. The mitochondrial DNA profile of 'Soltari' was found to be the same as that of 'Heuktari, and a nuclear DNA profile of 'Soltari' was similar as those of the parental strains, 'Suhan' and 'Heuktari.' 'Soltari' mycelium grows adequately in moderate to high temperatures of $12-20^{\circ}C$, although its optimum temperature was found to be $30^{\circ}C$. Fruiting body production per 1.1-L cultivation bottle was approximately 158.8 g. Its stipe length and thickness were comparable to those of diameter and thickness were somewhat lower (42.72 vs. 51.33 mm and 18.18 vs. 22.46 mm, respectively). 'Soltari' was found to be more resistant to high $CO_2$ atmosphere than 'Suhan', and the color of the pileus of 'Soltari' was dark gray at high temperature. Therefore, it is suggested that this new cultivar 'Soltari' is a good alternative cultivar and will contribute to energy saving in oyster mushroom farms.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.843-850
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• 2000

We have produced the microcapsule composed of ${\alpha}-tocopherol$ as a core material (Cm) and the gelatinized polysaccharide as a wall material (Wm). Firstly, we have developed a simple, sensitive, and quantitative analysis method of the microencapsulation product using 5% cupric acetate pyridine solution. We could then optimize all the conditions for the microencapsulation process such as the ratio of [Cm] to [Wm], the temperature of dispersion fluid, and the emulsifier concentration using response surface methodology (RSM). As for the microencapsulation of ${\alpha}-tocopherol$, the regression model equation for the yield of microencapsulation (YM, %) to the change of an independent variable could be predicted as follows : YM=99.77-1.76([Cm]:[Wm])-1.72$([Cm]\;:\;[Wm])^2$. From the ridge of maximum response, the optimum conditions for the microencapsulation of ${\alpha}-tocopherol$ were able to be determined as the ratio of [Cm] to [Wm] of 4.6:5.4(w/w), the emulsifier concentration of 0.49%, and dispersion fluid temperature of $25.5^{\circ}C$, respectively. Finally, the microcapsules produced under the optimal conditions were applied for the analysis of storage stability. The optimal conditions for the storage were found to be the values of pH 9.0 and $25{\sim}35^{\circ}C$. And the storage stability of the microcapsules containing ${\alpha}-tocopherol$ were higher than 99% for a week at pH 9.0 and $25^{\circ}C$.

• Korean Journal of Food Science and Technology
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• v.23 no.1
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• pp.44-51
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• 1991

The thermal resistance of the important microorganisms in takju. Korean traditional turbid alcoholic beverage, was measured and optimun heating time and temperature to achieve the commercial pasteurization of these microorganisms were examined. Most of the vegetative bacterial cells in takju were destroyed by heating at over $60^{\circ}C$, except for the spore forming organisms, which did not actively grow in takju after pasteurization. The important microorganisms for the quality deterioration of pasteurized takju were then appeared to be yeast and molds, and their thermal resistances were measured. The thermal resistances of these microorganisms changed greatly depending upon the heating method. The D values of yeast in takju were 3.5 min at $65^{\circ}C$ and 0.46 min at $80^{\circ}C$ in cap-tube, and 7.1 sec at $65^{\circ}C$ and 2.3 sec at $80^{\circ}C$ in a continuous coil heat exchanger. Those of molds were 2.7 min at 65℃ and 0.25 min at $80^{\circ}C$ in cap-tube, and 3 sec at $65^{\circ}C$ and <1 sec at $80^{\circ}C$ in the coil heat exchanger. The acidity and pH did not change at $30^{\circ}C$ for two weeks after pasteurization by heating in the coil heat exchanger at $65^{\circ}C$ for 17 sec, but the viscosity increased slightly by the heat treatment. Significant differences in sensory quality, especially the formation of burnt smell and bitterness by heating takju for 12D of yeast at $70,\;80\;and\;85^{\circ}C$, respectively, were observed and this resulted in the significant reduction in overall likeness of pasteurized takju. However, when the heating temperature was fixed to $80^{\circ}C$, the overall likeness of pasteurized takju did not affected significantly by the heating time ranging from 8D to 12D of yeast. It was concluded that the optimum pasteurization condition of takju in a continuous heat exchanger was heating at $80^{circ}C$ for 23sec(10D of yeast).

• Journal of Korean Society of Environmental Engineers
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• v.30 no.6
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• pp.659-665
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• 2008

This study is about zeolite synthesis from the sewage sludge incinerator fly ash of "S" sewage treatment center located in Seoul. For this purpose, the properties of raw fly ash as starting material, the hydrothermal conditions for zeolite synthesis and the environmental applicabilities of synthesized zeolites were examined. Fly ash from sewage sludge incinerator has large quantities of SiO$_2$ and Al$_2$O$_3$ and their contents are 42.8 wt.% and 21.2 wt.% respectively. So fly ash is considered to be possible starting material for zeolite synthesis. The results from leaching test of fly ash showed that the concentration of hazardous metals were very low as compared with the Korea leaching standard of the Waste Management Law. But the concentration from total recoverable test of fly ash were higher than the fertilizer standard of Fertilizer Management Law. Major zeolite products synthesized by hydrothermal reaction are analcime in teflon vessel and zeolite P1 in borosilicate flask. Optimum conditions for the synthesis of analcime were 1 N of NaOH concentration, 16 hour of reaction time and 135$^{\circ}C$ of reaction temperature. For the zeolite P1 formation, the proper conditions were demonstrated to be 5 N of NaOH concentration, 16 hour reaction time and 130$^{\circ}C$ of reaction temperature in this study. Hazardous metal contents in the analcime product are similar with those in raw fly ash. In case of the zeolite P1, the contents are reduced to nearly a half. Raw fly ash and the analcime product showed NH$_4{^+}$ ion exchange capacity of 0$\sim$1.0 mg of NH$_4{^+}$g$^{-1}$ and 3.0$\sim$7.4 mg of NH$_4{^+}$g$^{-1}$, respectively. However, the zeolite P1 product reached exchange capacity to 14.6$\sim$17.8 mg of NH$_4{^+}$g$^{-1}$. This values are in the range of those of natural clinoptilolite and phillipsite. From this point of view, zeolite synthesis from sewage treatment sludge incinerator fly ash is a good alternative for solid waste recycling.

• Applied Biological Chemistry
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• v.13 no.3
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• pp.207-218
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• 1970

Studies were carried out to develope the most economical and practical methods of packaging and preservation of kimchi, so commercialization of kimchi manufacture could proceed rapidly. The results obtained may be summarized as following. (1) It is generally established that the acceptable range of lactic acid content of kimchi is between 0.4% and 0.75%. Based on sensory evaluation, kimchi having lactic acid content below 0.4% and above 0.75% was not edible, and the time of optimum taste corresponded to the vicinity of 0.5% of lactic acid content. For the refrigeration storage with or without preservatives, the packaging kimchi in plastic film must be done at the lactic acid content of 0.45%, for lactic acid fermentation will continue slowly after the packaging. However, for the heat sterilized kimchi the packaging should be done at the 0.5% of lactic acid content for the best because lactic acid fermentation is completely stopped after the packaging. (2) Polyethylene, polypropylene, and polycello were chosen as suitable packaging materials. Polyethylene is cheapest among them but kimchi packaged in this film was damaged frequently in handling process and gave off kimchi flavor. On the other hand polypropylene also gave off kimchi flavor, but its higher mechanical strength gave better protection to kimchi and it had superior display effect due to the transparancy. Therefore polypropylene made much better packaging material. Polycello proved to be the best packaging material from the standpoint of physical characteristics but its price is higher than that of other plastic films. To be effective, the thickness of plastic films for packaging kimchi must exceed 0.08mm. (3) Keeping property of kimchi appeared to be excellent by means of freezing. However, by the time the frozen kimchi was thawed out at room temperature, moisture loss due to drip was extensive, rendering the kimchi too stringy. (4) Preservation of kimchi at refrigerated temperatures proved to be the best method and under the refrigerated condition the kimchi remained fresh as long as 3 months. The best results were obtained when kimchi was held at $0^{\circ}C$. (5) In general, preservatives alone were not too elective in preserving kimchi. Among them potassium sorbate appeared to be most effective with the four fold extension of self-life at $20^{\circ}C$ and two fold extension at $30^{\circ}C$. (6) In heat sterilization the thickness of packaged kimchi product had a geat effect upon the rate of heat penetration. When the thickness ranged from 1.5 to 1.8cm, the kimchi in such package could be sterilized at $65^{\circ}C$ for 20 minutes. Kimchi so heat treated could be kept at room temperature as long as one month without apparent changes in quality. (7) Among combination methods, preservation at refrigerated and heat sterilization could be favorably combined. When kimchi was stored at $4^{\circ}C$ after being sterilized at $65^{\circ}C$ for 20 minutes, it was possible to preserve the kimchi for more than 4 months.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.1
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• pp.43-55
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• 1976

Fertilization and early development of turbo cornutus was studied based on the samples which were collected in Yeosu area. Particular emphasis was paid on induction of artificial spawing, fertilization rate, preembryonic development, the growth of the early larva and larval survival to various salinity. Among the various methods for induction of artificial spawning which have been tested for the present study, drying by exposure to air is the. most efficient, and percentage fertilization rate was $83.8-96.4\%$. The diameter of fertilized eggs was $0.182{\pm}0.0028mm$; and the diameter of egg membrane was $0.245{\pm}0.093mm$. Under the temperature range of $20.6-25.4^{\circ}C$ the larvae hatched out after 11:05-11:15 hours of fertilization. After 3.0-3.5 days of fertilization the planktonic larvae begand to settle, and the settlement terminated within 5 days. During the period of 150 days of early culturing the diameter growth of shell(M) and the diameter of shell aperture(A) was formulated as follows: $$1972\;M=0.33e^{0.02070D}$$ $$A=0.19e^{0.02282D}$$ $$1973\;M=0.32e^{0.02282D}$$ $$A=0.16e^{0.02596D}$$ During the same period of early culturing the relative growth of shell diameter and the diameter of shell aperture was formulated as follows : 1972 A=0.6478 S-0.1575 1973 A=0.5897 S-0.0515 After 11 days of larval hatching $0.02-0.18\%$ of planktonic larvae settled. After 150 days of settlement the survival rate of the early shells was $7.4-21.6\%$. Under the temperature range of $21.0-22.7^{\circ}C$ the optimum salinity range for the development of egg and the planktonic larvae was $30-35\%_{\circ}$.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.286-294
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• 2014

The purpose of this study is to investigate the effects of applying density current generator (hereafter referred to as DCG to large lakes on the operating conditions of DCG, de-stratification, water quality improvement and inhibition of algae occurrence. As a result of a survey conducted to derive the optimum operating parameters of DCG in a condition to minimize eco-toxicity, the following conclusions were obtained. During the survey period, a marked stratification appeared in September to October 2011 and May 2012. At this time, the average depth of water to form thermocline was found to be $5{\pm}2$ m, so the location of discharge port for the operation of DCG was determined to be about 5 m below from the surface. To minimize the adverse effects of benthos and obtain the effect of water mixture at the time of water circulation, the mixing ratio of surface water and deep water was designed to be 3:1 by means of ecotoxicological assessment on the DCG operating characteristics. To select the appropriate operating hours for DCG, DCG was operated by 12 hr, 24 hr, 36 hr and 48 hr. As its result, the formation of thermocline did not occur during the operation of 36 hr. Also, It was effected that start reoperating from 3rd day after stop 2days under the condition of operated during 36 hr with calculated power consumption. Under the above conditions, the results of DO and water temperature analysis during the operation of DCG showed that the stratification, which was distinct previously, appeared to be weak, and relatively lower levels than those before operation were found as a result of water quality analysis on COD and chlorophyll-a, which leads to the conclusion that the water body is maintained at a stable condition due to the circulation of water by the occurrence of density current resulting from the operation of DCG.

• Korean journal of applied entomology
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• v.57 no.2
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• pp.57-64
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• 2018

The fungus gnat, Bradysia difformis, has been recognized as an important pest of greenhouse crops. There is a need for research on the control of the fungus gnat. However, it is difficult to obtain many generations of the fungus gnat for several kinds of research. Indoor propagation is a very useful method for obtaining enough individuals in cases where the need is for larvae in soil. This study was conducted to determine the optimum growing media and temperature conditions for rearing the fungus gnat in the laboratory. Under experimental temperature conditions, hatching, pupation, and eclosion rates were the highest at $20^{\circ}C$. The developmental period of the fungus gnat was shortened with higher temperatures. The greatest number of eggs was an average of 144 at $20^{\circ}C$. Using different types of larvae growth media, the highest hatching rates were 84.7 and 84.4% in water agar and potato disks, respectively. The larval period was the shortest, at 14.7 days, when grown on potato disks. The highest pupation and eclosion rates were 85.2 and 82.6% on potato disks, respectively. The highest number of eggs was an average of 125.6 on potato disks. Regarding the effects of different growth media on the eclosion rate of B. difformis, the highest eclosion rate was 88.4% on the soil mix, and was 50% on oatmeal, 25% on shredded potato. The results of four different inoculation levels of larvae on eclosion rate of B. difformis showed that the highest eclosion rate was 84.7% for 1,000 larvae. The eclosion rate was shortened with a higher number of larvae inoculated/cage. In the growth medium used, 3,000 eggs were better for the initial level of inoculation, showing a relatively high emergence rate and short developmental period. Mass rearing procedures were explained in detail.