• Korean Journal of Food Science and Technology
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• v.41 no.4
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• pp.399-404
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• 2009

The goal of this study was to improve the quality of cheonggukjang by the optimization of the inoculation methods of the Bacillus subtilis (B. subtilis) and Lactobacillus plantarum (L. plantarum) strains. In order to optimize the mixed cultivation of B. subtilis and L. plantarum, the B. subtilis strain was inoculated into steamed soybeans after cultivation of L. plantarum. Inoculation size of B. subtilis was changed to the simultaneous inoculation method in order to stimulate the growth of the L. plantarum in cheonggukjang. The viable cell count of L. plantarum increased from $2{\times}10^7$ CFU/g to $2-6{\times}10^8$ CFU/g and B. subtilis grew to $9{\times}10^8$ CFU/g. These results showed that 2 strains were successfully able to grow in the steamed soybean for good quality of cheonggukjang by optimization of the inoculation methods. The sensory evaluation indicated that a favorable aroma and overall acceptance of cheonggukjang by the optimized mixed cultivation of B. subtilis and L. plantarum, which was relatively higher than those of cheonggukjang by single strain inoculation of B. subtilis.

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.139-146
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• 2000

산업적으로 유용한 미생물 유래 셀룰로오스를 생산 이용하기 위해 전국 각지 양조식초의 덧으로부터 세룰로오스의 생산성이 높고 조질의 균일성을 나타내는 균주를 분리하였다 분리균 GS11은 gram 음성이고 간균(0.6$\times$2.2~3.2 $\mu\textrm{m}$)의형태를 하고 있으며 편모를 가지고 있어 운동성을 보였다. 또한 세포내 지방산 조성은 다량의 불포화 지방산 {{{{ {C}_{18:1} }}}}과 포화지반산 {{{{ {C}_{16:0 } }}}}, {{{{ {C}_{14:0 } }}}} 이 대부분을 차지하였고 DNA 염기조성 (G+C) 함량은 58.4% 이였으며 ubiqunone 은 {{{{ { Q}_{10 } }}}}을 갖는 것으로 나타났다 이러한 형태학적 생리.생화학적 특성의 결과에 따라 본 균주는 Acetobacter xylinum GS11으로 동정되었다 A. xylinum, GS11 의배양기간 동안 셀룰로오스 생산성을 검토하고자 250mL 삼각플라스크에 균주를 접종하여 $30^{\circ}C$에서 12일간 정치배양하였다 그결과 기질인 glucose의 소비는 접종 후 급소하게 감소하여 셀룰로오스 생산에 이용되었으며 셀룰오스의 생산은 배양 9일 경에 2.8g/l로 최대의 생산량을 나타냈다.

• Research in Plant Disease
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• v.18 no.4
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• pp.317-323
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• 2012

The study aims to identify the pathogenicity of Phytophthora. capsici isolates in major pepper-producing areas in Korea and the inherit genetic pattern of phytophthora blight resistance by inocula. With five kinds of testing materials including 'Kataguma (Sakata Korea)' peppers, a disease-susceptible material, '#308', a phytophthora blight resistance material, 'CM334', and their $F_1$ and $F_2$, respective isolates of P. capsici obtained from Icheon, Eumseong, Buan, Imsil and Yeongyang regions together with six kinds of peppers' inoculum including PA-159 (KACC No.40482) received from Korean Agricultural Culture Collection were used for inoculation. The disease-susceptible material '#308', the resistant material 'CM334' and the non-segregating generation of $F_1$ represented 4.94-5.00, 1.00-1.07, and 1.01-1.08 phytophthora blight incidence respectively in the group comparison by isolate. This result means that the phytophthora blight resistance was clearly distinguished among testing materials in the group comparison by P. capsici isolate. Moreover, $F_2$ segregating generation showed 1.79-2.31 phytophthora blight incidence which turned out to be identical in the group comparison by the six isolates of P. capsici isolate and with similarity between both the resistant and susceptible materials. Thus, the result proved that using the six isolates of P. capsici tested as inocula was suitable to investigate the phytophthora blight resistance. When it comes to group comparison of $F_2$ segregation generation, however, isolates were divided with PA-159 isolate being the center: a group consisting of isolates from Icheon, Buan, and Imsil and a group consisting of Yeongyang and Eumseong isolates with higher pathogenicity. The expected segregation ratio of the phytophthora blight resistance in $F_2$ generation by isolate was analyzed. PA-159 isolate showed 3:1 or 9:3:3:1, indicating that one to two genes were involved. On the other hand, results also proved that there is an interaction of genes since both Eumseong and Yeongyang isolates showed a segregation ratio of 11:5 while the Icheon isolate represented 12:3:1.

• Food Science and Preservation
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• v.22 no.4
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• pp.545-552
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• 2015

This study investigated the quality characteristics of popped rice Doenjang prepared with different Bacillus strains (Bacillus subtilis KACC 15935, and Bacillus subtilis HJ18-9). The changes in the enzyme activity (protease, cellulase, and ${\alpha}$-amylase), amino-type nitrogen and ammonia-type nitrogen contents, and the reducing sugar were investigated during the fermentation period. Enzymes such as protease, cellulase, and a-amylase plays an important role in the changes in composition of nutrients, and in flavor and taste of popped rice Doenjang. Protease activities of the popped rice deonjang fermented with different Bacillus strains (control, B. subtilis KACC 15935, and B. subtilis HJ18-9) was in the range of 171.77-185.97 unit/g at the beginning of fermentation, and there were no significant differences among the samples. On the other hand, the protease activity in popped rice Doenjang fermented with B. subtilis HJ18-9 increased significantly up to $248.77{\pm}4.53unit/g$ at the end of fermentation (p<0.05). Cellulase activity and a-amylase activity of popped rice Doenjang in HJ18-9 was higher than these of other samples. After 56 days of fermentation, amino-type nitrogen in popped rice deonjang fermented with control, B. subtilis KACC 15935, and B. subtilis HJ18-9 increased significantly up to $174.99{\pm}3.70$, $166.59{\pm}1.40$, $225.39{\pm}3.70mg%$, respectively (p<0.05). These results suggested that B. subtilis HJ18-9 was a suitable starter for the preparation of soybean paste.

• Korean journal of applied entomology
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• v.26 no.3 s.72
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• pp.171-178
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• 1987

Pathogenic isolates of Alternaria mali produced host-specific toxin(AM-toxin) in liquid culture. The toxin was also released by germinating spores of the fungus. The physiological event of apple leaves induced by germinating spores was an increased loss of electrolytes from susceptible leaves. This reaction was evident soon after spore inoculation, indicating that the leakage was caused by AM-toxin from germinating spores. Typical symptoms were developed only in susceptible leaves of apple within 48hr after inoculation with pathogenic spores. Similar symptoms occurred on susceptible leaves when non-pathogenic isolates plus AM-toxin were used.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.148-156
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• 2016

This study examined effects of Enterobacter ludwigii SJR3 showing a high 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, on growth of tomato plant and its expression of stress-related genes under drought and salt stress. SJR3 strain was inoculated at $10^6cell/g$ soil to 4-week grown tomato plants, and drought and salt stresses were treated. After additional incubation for 1 week, root length, stem length, fresh weight and dry weight of tomato plants treated with SJR3 increased by 37.8, 37.2, 96.8 and 146.6%, respectively compared to those of uninoculated plants in drought stress environment, and they increased by 19.2, 25.4, 19.5, and 105.8%, respectively in salt stress environment. Proline content in tomato leaves increased significantly under stress conditions as one of a protecting substance against stresses, but proline contents in tomato treated with SJR3 decreased by 62.1 and 54.1%, respectively. Relative expression of genes encoding ACC oxidase, ACO1 and ACO4, ethylene response factor genes ERF1 and ERF4, and some other stress-related genes were examined from tomato leaves. Compared to the non-stressed tomato, expressions of all stress-related genes increased significantly in the stressed tomato, but gene expressions in the inoculated tomato were similar to those of no-stressed control tomato. Therefore, E. ludwigii SJR3 may play an important role in mitigating drought and salt stress in plants, and can increase productivity of crops under various abiotic stresses.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.210-219
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• 2017

This study was conducted to establish an efficient screening method for radish (Raphanus sativus) cultivars that are resistant to black spot, which is caused by Alternaria brassicicola. Seven A. brassicicola isolates were selected and investigated for their ability to produce spores and pathogenicity. Of these isolates, A. brassicicola KACC 40036 and 43923 produced abundant spores in V-8 juice agar medium and showed pathogenicity and strong virulence on radish seedlings. We examined the resistance of 61 commercial cultivars of radish to A. brassicicola KACC40036, and found that there are no highly resistant radish cultivars; however, some cultivars, such as 'Geumbong' and 'Searom', showed weak resistance to A. brassicicola. For further study, we selected four radish cultivars that showed different disease responses to A. brassicicola KACC40036. According to the growth stage of the radish seedlings, inoculum concentration, and incubation temperature of radish, development of black spot on four cultivars has been investigated. The results showed that younger seedlings were more sensitive to A. brassicicola than older seedlings, and the disease severity depended on the concentration of the spore suspension. The disease severity of plants incubated in humidity chamber at $25^{\circ}C$ was greater than that of plants grown at $20^{\circ}C$ or $30^{\circ}C$. Taken together, we suggest the following method for screening for radish plants that are resistant to A. brassicicola: 1) inoculate 16-day-old radish seedlings with an A. brassicicola spore suspension ($2.0{\times}10^5spores{\cdot}mL^{-1}$) using the spray method, 2) incubate the inoculated plants in a humidity chamber at $25^{\circ}C$ for 24 h and then transfer the plants to a growth chamber at $25^{\circ}C$ with 80% relative humidity under a 12 h light/dark cycle, and 3) assess the disease severity of the plants two days after inoculation.

• Food Science and Preservation
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• v.24 no.5
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• pp.707-713
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• 2017

The objective of this study was to select yogurt starter from Korean traditional fermented foods. The 2 strains (KM24, KM32) among 50 strains of isolated lactic acid bacteria selected as starter based on milk clotting ability, antimicrobial activity against various pathogens, tolerance in artificial gastric and bile juice and growth in 10 % skimmed milk. The strains were identified as Lacobacillus plantarum (KM32) and Pediococcus pentosacesus (KM24) by 16S rRNA gene sequencing. Viable cell number of yogurt fermented with mixed strains (KM24 and KM32) was 9.66 log CFU/mL after fermentation for 48 h and maintained $10^9CFU/mL$ during fermentation for 72 h at $37^{\circ}C$. The pH and titratable acidity of mixed cultured yogurt were 4.25% and 0.83% after fermentation for 48 h at $37^{\circ}C$, respectively. The physico-chemical characteristics of mixed cultured yogurt after fermentation for 48 h were $38.45{\mu}g/mL$ (polyphenol content), 48.57% (DPPH radical scavenging activity) and 465.40 cp (viscosity), respectively. The mixed cultured yogurt maintained $10^9CFU/mL$ of lactic acid bacteria during storage 10 days at $4^{\circ}C$. The viable cell number of yogurt prepared with mixed culture(KM32+KM24) maintained higher and than that of control (L. casei) during storage. These results indicated the potential use of selected strains (KM32+KM24) isolated from kimchi as a yogurt starter with strong acid tolerance and probiotics properties.

• Korean Journal of Soil Science and Fertilizer
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• v.23 no.3
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• pp.220-226
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• 1990

This experiment was carried out to study the effects of Bradyrhizobium moculation and fertilizer N application on symbiotc $N_2$ fixation of peanut (Arachis hypogaea L. cv. Younghotangkong) at newly reclaimed soil. Treatments consisting of B. sp. (Vigna) HCR-3 and HCR-46 with control and five levels of nitrogen (0, 4, 8, 16, 32kg/10a) were arranged with split design of four repetitions. The results obtained were as follows. The number of viable Bradyrhizobium in rhizosphere was decreased to 20 days after sowing and thereafter it was remarkably increased, until full ripe stage of pods, decreased as fertilizern rates increased. Nodulation and nitrogenase activity were reduced with increasing levels of fertilizer, whereas top dry matter and nitrogen accumulation where increased. Seed yield of Bradyhizobium inoculation under the fertilizer N zero level was similar to that N : 8kg/10a under uninoculation. It suggested that Bradyrhizobium inoculation could replace the effect of nitrogen application.

• Korean Journal of Organic Agriculture
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• v.14 no.4
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• pp.399-410
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• 2006

This study was carried out to identity the effects of antifungal bacteria isolated from the soil grown kiwi fruit plants on the growth inhibition of Botrytis cinerea causing gray mold in kiwi fruit plants in the southern districts of Jeonnam. Two hundred and fifty antagonistic microorganisms were isolated and examined into the antifungal activity against Botrytis cinerea. We screened and isolated four bacterial strains which strongly inhibited Botrytis cinerea from the soil grown kiwi fruit plants. And the best antifungal bacterial strain which called CHO 163 was finally selected. Antagonistic microorganism CHO 163 was identified to be the genus Bacillus sp. based on the morphological and biochemical characterization. Bacillus sp. CHO 163 showed 86.9% of antifungal activity against Botrytis cinerea. By the bacterialization of culture broth and heated filtrates of culture broth, Bacillus sp. CHO 163 showed almost all of antagonistic activity against Botrytis cinerea. And we also confirmed that in vitro the treatment of Bacillus sp. CHO 163 cultured by SD+B+P broth efficiently controled the growth of Botrytis cinerea causing gray mold in kiwi fruit plants.