• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.249-255
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• 2004

Chinese cabbage ('Baechu') Kimchi was fermented at the three different temperatures right after it was prepared. Samples were taken everyday for measuring bacterial populations, pH, and titratable acidity through the whole periods of fermentation up to 50 days. pH values and developed acidity were significantly affected by the fermenting temperatures of 4, 10, and $20^{\circ}C$, suggesting that different bacterial flora has been established by the temperatures exposed. The modified MRS agar containing vancomycin (300 $\mu$g/mL) was used for isolating the vancomycin-resistant LAB strains and 127 isolates were finally obtained. Of the LAB isolates, 13 isolates were subjected to the identification experiments based on the biochemical characteristics and the molecular-typing approach, an ITS-PCR, whether they belong to the genus Leuconostoc or not. The data obtained from API 50 CHL kit resulted that six isolates were identified as the members of Leuconostoc and six as Lactobacillus brevis strains except for a single isolate YKI 30-0401, which was not able to be identified because its biochemical traits were not matched to the database of API 50 CHL kit. It was noted that some isolates were distinct in a couple of some biochemical characteristics compared with those of the reference Leuconostoc species. To overcome the limitations experienced in the commercial identification products above, an ITS-PCR experiment was also conducted for the isolates, resulting that eight isolates belong to Leu. mesenteroides ssp. mesenteroides or dextranicum with a single band of 564 bp, and four to L. brevis strains. The ITS-PCR profiles clearly differentiated the closely-related LAB isolates for which same results were obtained by the biochemical method. This molecular approach, however, failed to produce the amplicons for the YKI 20-1003, leaving the strain unidentified. Judging from the identification data obtained in the Kimchi fermented at $4^{\circ}C$ or $10^{\circ}C$, Leuconostoc spp. including Leu. mesenteroides/dextranicum were likely predominant species in the earlier stage and L. brevis occurred at the high level through the whole period. By contrast, L. brevis, as one of the major flora, possibly lead the fermentation from the beginning in the Kimchi fermented at $20^{\circ}C$.}C$.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.180-186
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• 1985

Field and phytotron experiments were conducted to determine the effect of morphological growth stage and environmental temperature on Weender components and net energy lactation (NEL) in corn cv. Blizzard and sorghum cv. Pioneer 931 and Sioux at Munich Technical University from 1978 to 1981. Various growth stages of maize and sorghum were grown for 42 days at 4 temperature regimes (30/25, 25/20, 28/18 and 18/8 degree C) and mid-summer sunlight over 13 hour days. The results obtained are summarized as follows: 1. Accumulation of crude protein in maize and sorghum plants was associated with leaf weight ratio and leaf area ratio ($P{\leq}0.1%$). Crude protein in the plants were shown to have a greate synthesis rates at early growth stages. The highest concentration of crude protein were found at 3-leaf stage with 31.4% and 33.9% for maize and sorghum, respectively. 2. Synthesis of crude fiber was increased after growing point differentiation markedly and were shown the highest concentration at heading stage with 28.4% and 31.5% for maize and sorghum, respectively. During the maturities, the crude fiber contents in maize were, however decreased and shown a value of 19.5% at physiological maturity, while that of sorghum were increased continuously. 3. NEL value in maize and sorghum plants were declined as morphological development and shown the lowest at growing point differentiation with 5.82 MJ (maize) and 5.46 MJ/kg (sorghum). During the late maturity, the NEL value of maize were increased markedly and shown a value of 6.70 MJ and 6.94 MJ/kg for milkstage and maturity stage, respectively, while NEL value in sorghum were not increased markedly. 4. Net energy lactation in maize and sorghum plants were associated with synthesis rate of non-structural carbohydrates, especially mono- and disaccharose while cell-wall constituents and crude fiber lowerd NEL contents ($P{\leq}0.1%$). 5. NEL accumulation and starch value were decreased under temperature. The NEL concentration of 4-leaf sorghum under different environmental temperatures of 30/25, 25/20, and 18/8 degree C were 4.87 MJ, 5.46 MJ and 5.81 MJ/kg, respectively.

• Journal of Animal Environmental Science
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• v.6 no.3
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• pp.191-199
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• 2000

This study was initiated to investigate the influence of biophysical condition on the composting characteristics, and conducted to develop technology for using recycled compost as a bulking agent cost to reduce operating cost. To methods of aeration, continuous aeration (CA: run No. I) and intermittent aeration (IA: run No. 2) were performed with three 12.3 liter laboratory scale vessels for ten days. Manure and rice hulls were mixed for thirst trial (I), rice hulls and recycled compost after first trial were mixed for second trial (II), dairy manure and only recycled compost after second trial were mixed for third trial (III). During the composting process, temperatures of the compost mass and ammonia emissions were measured. The quality and maturity of compost were ascertained by examining the characteristics and composition of the compost. Also, loss of mass was determined by measuring the mass of materials in the vessels before and after composting. The results in this study are as follows: 1. The periods of optimum temperature ($>55^{\circ}C$) to kill pathogens were maintained from 38 to 78 hours for CA and from 60 to 98 hours for IA. 2. The more recycled compost mixed, the more ammonia emitted. The maximum ammonia emissions were 287 ppm at CA and 420 ppm at IA. 3. Biofiltration system was required for the compo sting system using only recycled compost as an amendment, because the ammonia emissions was produced above 100 ppm at the end of composting process. 4. The quality and maturity of compost: - Fresh compost, were required drying, because moisture contents of the compost were approximately 70% in all tests. - The pH values were observed to rise smoothly, from 7.9 to 8.3 at CA and from 8.4 to 8.6 at IA. The CfN ratios of the fresh compost were ranged form 21.05 to 16.42 for CA and from 22.81 to 14.75 for IA. The final C/N ratios for test II and III were below 20.were below 20.

• The Korean Journal of Mycology
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• v.5 no.1
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• pp.13-19
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• 1977

In order to investigate histopathologically the nature of varietal resistance and infection process of the rice bast fungus, Pyricularia oryzae. this experiment was undertaken by using the resistant cultivar Tongil and susceptible cultivars Norin No.6 and Jinheung in 1973 to 1974. 1) It was found that appressorium of the fungus forms not only at 4 hours after incubation under the favorable conditions but also peak of appressorial formation is at 48 hours treatment. Physical stimulus known to be a definite factor for appressorial formation. The optimum temperature range for appressorial infection was at $24^{\circ}C$ to $28^{\circ}C$, and pH was between 4.8 to 8.0 with 6.8 as the optimum. 2) Although percent of appressorial formation on the leaves of resistant Tongil and susceptiible Norin No.6 were only slightly different, there was a remarkable difference between resistant and susceptible cultivars with regard to percent of hyphal infection and index for hyphal extension. Index of hyphal extension was 1.6-2.7 in Tonyil. while in susceptible cultivar was 3.4-6.6. The rate of discoloration of infected cells, a indication of hypersensitivity, was greater in the resistant than in susceptible cultvar. 3) Therefore, it could be concluded that resistance of Tongil cultivar may be attributable to a higher degree of mechanical barriers as well as a higher level of antifungal substance accumulation.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.43-51
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• 2022

This study was conducted to investigate the effect of ventilation at high temperature on the control of powdery mildew, silverleaf whitefly two-spotted spider mite occurred at Korean melon cultivation greenhouse, and on leaf rolling and flowering of the plant in summer season. 'Alchanggul' grafted onto 'Hidden Power' rootstock was planted on soil bed with the distance of 40 cm. Three ventilation temperatures of 45℃, 40℃, and 35℃ as set points were compared. Ventilation treatment was done by control of side window operation from 18th June to 13th July when silverleaf whitefly, mite, and powdery mildew were occurred in all greenhouses. The temperature inside greenhouse was increased up to the set temperature point on sunny days and maintained for about 9 hours with high relative humidity at 45℃ condition. The differences of day maximum air temperature and day minimum RH were the highest at 45℃ treatment. After 11 days of treatments, the damage by powdery mildew and two-spotted spider mite was almost recovered at 45℃ treatment but not at 40 and 35℃. The population of silverleaf whitefly and two-spotted spider mite were significantly decreased at 45℃ treatment at 14 days after treatment, while powdery mildew symptom was not significantly decreased. Leaf rolling was observed at high temperature but not severe at 45℃ treatment. After 26 days of treatments, female flowers did not bloom at all at 45℃ treatment, and the number of male flowers was 1.2 among 15 nodes of newly grown shoots. As the result, it indicates that ventilation at the high temperature of 45℃ for about 2 to 3 weeks can be an applicable method to control above mentioned pests and disease, and to recover the vegetative growth of Korean melon by reducing flowering of the plant.

• Journal of Applied Biological Chemistry
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• v.60 no.1
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• pp.79-86
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• 2017

Microbes in forest are very important due to not only to enhance soil fertility but also maintain a healthy ecosystem by supplying the energy available to living organisms by producing various kinds of enzymes related to degradation of lignocellulosic biomass. In order to isolate a lignocellulosic biomass degrading bacterial strain from the Jurassic park located in Gyeongnam National University of Science and Technology, We used the Luria-Bertani-Carboxymethyl cellulose (CMC) agar trypan blue method containing 0.4 % carboxymethyl cellulose and 0.01 % trypan blue. As a result, we isolated a bacterial strain showing both activity on the CMC and xylan. To identify the isolated strain, 16S rRNA sequencing and API kit analysis were used. The isolated strain turned out to belong to Bacillus species and then named Bacillus sp. GJY. In the CMC zymogram analysis, it showed that one active band of about 28kDa in size is present. Xylan zymogram analysis also showed to have one active band of about 25kDa in size. The optimal growth temperature of Bacillus sp. GJY was $37^{\circ}C$. The maximal activities of CMCase and xylanase were 12 hour after incubation. The optimal pH and temperature for CMCase were 5.0 and $40^{\circ}C$, respectively, whereas the optimal pH and temperature for xylanase was 4.0 and $40^{\circ}C$. Both activities for CMCase and xylanase showed to be thermally stable at 40and $50^{\circ}C$, while both activities rapidly decreased at over $60^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.5
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• pp.612-617
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• 2008

Tetrodotoxin (TTX) analogues were first determined from the liver extracts of puffer fish, Takifugu niphobles, by LC/MS with Hydrophilic Interaction Liquid Chromatography (HILIC). In total, 7 TTX analogues were detected within 20 minutes as follows; 5,6,11-trideoxyTTX (34.0%, 1,029.6 nmol/g), 6,11-dideoxyTTX (29.3%, 887.6 nmol/g), TTX (22.1%, 667.8 nmol/g), 4,9-anhydro-TTX (11.2%, 339.3 nmol/g), 11-deoxyTTX＋5-deoxyTTX (2.6%, 78.6 nmol/g), and 4-epiTTX (0.8%, 23.6 nmol/g). Mouse toxicity of diluted liver extracts showed the highest toxicity at pH 3 (8.7 MU/mL) and decreased, as increasing pH, to 1.4 MU/mL at pH 10. At acidic (pH 5) and neutral conditions (pH 7), mouse toxicity of liver extracts (79 MU/mL) decreased slowly, as increasing temperature from $80^{\circ}C$ to $115^{\circ}C$, and time until 1 hour; in contrast, at the akaline condition (pH 9), the toxicity decreased rapidly to the more than half within 10 minutes. Individual toxicity of the fillet of T. niphobles were between $43.2{\sim}106.7$ MU, and $64{\sim}78%$ of its toxicity was eluted to soup when boiled with 3 volumes of water during 10 minutes.