• Journal of Korean Society of Environmental Engineers
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• v.36 no.4
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• pp.265-270
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• 2014

Protease producing microorganisms were isolated from many kinds of food waste and fermented foods, which contains high amount and variable kinds of degraded substances. Several microorganisms were identified by 16S rRNA full sequencing analysis methods. The activity of protease was analyzed and identified in variable conditions for the application. For industrial use for biowaste treatment some proteases were isolated, identified and selected from microbial cells. And the tests were carried for the further use. The protein degrading activity at low temperature is useful for the treatment of organic waste, which contains much proteins. By the protein degradation process the organic waste can be utilized in variable fields, for example from feedstuff supplement to fertilizer for agriculture. Bacterial cells with protease activity at low temperature were isolated and identified. The optimal conditions for microbial cultivation and protease production were studied.

• Korean journal of applied entomology
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• v.36 no.3
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• pp.249-255
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• 1997

The sublethal temperature (5$^{\circ}$C for 2hr) led the fifth instar larvae of beet armyworm, Spodoprern exigucr (Hiibner), to increase cold tolerance to subzero lethal temperatures ( 'rapid cold hardening' ). The strength of rapid cold hardening was, however, varied among different populations which showed different cold tolerance in response to cold temperatures. To analyse the physiological factors affecting the rapid cold hardening, hernolymph osmolalities. supercooling points, glycerol contents, and cold stress proteins were measured by treating the fifth instar larvae with the sublethal low temperatures. The treated larvae showed increase of hemolymph osmolalities and glycerol contents. Changes of the osmolalities were greater in cold-hardy strains than in cold-susceptible strains. The sublethal temperature also induced them to express the cold-stress proteins (I0 - 20kD) in the hemolymph. but did not to change supercooling points.

• Korean journal of applied entomology
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• v.36 no.3
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• pp.256-263
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• 1997

Supercooling points (SCP) and cold tolerance of the tobacco cutworm, Spodol~rera litura Fabricius. were measured in response to subzero temperatures. SCPs were varied among developmental stages. Eggs showed the lowest SCP (-27$^{\circ}$C). Pupae and adults had the intermediate SCP(- 18$^{\circ}$C). The SCPs (- I0 to - 16$^{\circ}$C) of larvae increased with their ages. Lethal low temperature of each stage was higher than its SCP. Preexposure of eggs and larvae to a sublethal low temperature increased their survival capacities under lethal low temperatures. The sublethal temperature also induced the fifth instar larvae to increase hemolymph osmolality and to produce cold-induced proteins of apparent molecular weights of 20 and 27 kD. These results indicate that this species is classified into a freeze-susceptible insect.

• Korean journal of applied entomology
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• v.60 no.2
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• pp.193-199
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• 2021

Solenopsis japonica, which is belonging to Formicidae in Hymenoptera, is a native ant species in Korea. However, it had not been studied for cold hardiness of S. japonica to understand on its overwintering mechanisms in field so far. Cold tolerance on developmental stages was measured at different cold temperature with various exposure times. Workers showed more survival at 5℃ and 10℃ compared with other stages and elevated cold tolerance when workers were exposed at 15℃ for more than 12h incubation as a rapid cold hardening (RCH) condition. RCH treatment not only increased survival of workers at cold temperatures, but also decreased supercooling point (SCP) and freezing point (FP). RCH group increased the survival rate by 44% at 10℃ compared with Non-RCH group. SCP and FP were depressed from -10.0 to -14.2℃ and from -11.3 to -15.3℃, respectively, after RCH treatment. Cold temperature increased expression level of cold- and stress-related genes such as glycerol kinase and heat shock protein. These results indicate unacclimated cold tolerance of S. japonica and its acclimation to low temperature by RCH.

• Korean journal of applied entomology
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• v.34 no.4
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• pp.287-294
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• 1995

Studies were carried out to elucidate the efficacy of exogeneous 20-hydroxyecdysone treatment on terminating pupal diapause in the fall webworm. Hyphantria cunea Drury. And the difference was also investigated between normal adult development and post-diapause development after 20-hydroxyecdysone treatment. In the diapause termination rate of pupae treated with 20-hydroxyecdysone after storage for various periods at 16L:8D and $25\pm$$1^{\circ}C$, at the highest rate was observed from the group stored for the longest period and the lowest rate from those stored for 1.5 months. The time needed for adult emergence was inversely proportional to the chilling (at $0\pm$$1^{\circ}C$) period, and the longer its exposure period at low temperature, the higher its sensitivity to 20-hydroxyecdysone treatment. Pupal diapause duration was almost the same, regardless of storage period in the total darkness or at the photoperiod of 16L:8D, and also they successfully emerged to adult even without any experience at low temperature. The oxygen consumption rate in normally developing pupae showed nearly a typical U-form. But, that of diapausing pupae treated with 20-hydroxyecdysone slowly increased and jumped 14 days after the treatment. Pupal diapause began before formation of adult tissues, an a timing of adult tissue formation coincided with ascending timing of the metabolic rate in both normally developing pupae and diapausing pupae treated with 20-hydroxyecdysone. The diapausing pupae treated with 20-hydroxyecdysone was similar to normally developing pupae in band patterns of proteins from haemolymph or fat body.

• Food Science and Preservation
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• v.23 no.5
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• pp.666-672
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• 2016

The objective of this study was to evaluate the effects of low temperature-adapted Saccharomyces cerevisiae Y297 and fermentation temperatures on the quality of Yakju brewed. Physicochemical properties of Yakju brewed were compared pH, total acidity, ethanol, free amino acid, organic acid contents, and volatile flavor compounds in S. cerevisiae Y297 with control treatment. Cooked non-glutinous rice and saccharogenic amylase in koji were mixed with ethanol-producing yeasts and then fermented at $15^{\circ}C$, $20^{\circ}C$, and $25^{\circ}C$ for 20 days. Yakju brewed using the Y297 treatment showed the highest ethanol yield (17.9%) at $20^{\circ}C$. Expression of heat shock protein (HSP) 104 was evaluated by immunoblotting as an indication of adaptation to low temperatures ($15^{\circ}C$); levels of the HSP104 protein were higher in the Y297 treatment than in the control. Organic acid analysis showed that the lactic acid content of Yakju brewed using the control was the highest at $25^{\circ}C$. Finally, free amino acid analysis showed that the Y297 treatment had a higher proportion of essential amino acids than the control. Overall, these results indicate that S. cerevisiae Y297 could be used as a suitable yeast for Yakju brewed under low temperature ($15^{\circ}C$) condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.350-359
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• 1993

The effect of gibberellic acid ($GA_3) and abscisic acid (ABA) on KCl-enhanced proteolysis of senescing leaves of rice(Oryza sativa L. cv. Chilsung) was studied. Emphasis was given to their effects on KCI-enhanced efflux of amino acids and proteinase activity. When treated singly, $GA_3 affected leaf proteolysis little, while ABA increased proteolysis, the rate of amino acid efflux, and ribulose -1,5 -bisphosphate carboxylase / oxygenase (Rubisco)-degrading endoproteinase activity. An additive increase in all three parameters mentioned above was observed when leaves were treated with ABA and KCl. No such an additive effect was found when $GA_3 was treated with KCl. Both $GA_3 and ABA helped to alleviate the KCI-suppressed activity of Rubisco-degrading exoproteinases. The additive increase in proteolysis of rice leaves in the presence of both ABA and KCl could thus be ascribed to a further increase in the efflux of protein hydrolyzates and Rubisco-degrading endoproteinase activity. An increase in proteolysis was accompanied by a decrease in water absorption, and the combined treatment of ABA with KCl resulted in a further reduction of water absorption.

• Food Science and Preservation
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• v.23 no.3
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• pp.291-300
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• 2016

Kiwifruit (Actinidia chinensis, Hayward) was stored at $25^{\circ}C$ for 0~30 days and investigated to find out the optimum storage time to obtain the best physical and functional properties for consumers' preference. Kiwifruits was stored at different time period (0, 5, 10, 15, 20, and 30 days) for investigating their physiochemical quality, nutritional components, and functional characteristics. Kiwifruits stored for 20~30 days showed the best physiochemical quality such as higher total acidity and proper firmness. They were also more enriched with dietary fibers, free sugar, and organic acid, although no significant changes were observed in crude protein, crude fat, and moisture content. For functional properties, kiwifruits stored for 20 days showed significantly higher contents of total phenolics, flavonoids, and actinidin. In addition, it showed stronger antioxidant activity, whitening effect, and proteolytic activity when compared with other samples. SDS-PAGE analysis showed the presence of actinidin enzyme in kiwifruits. These results indicated that the kiwifruits stored for 15~20 days possessed excellent quality and high concentrations of nutritional and functional compounds, which could be best for both fresh consumption and product processing.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 1978.10a
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• pp.204.2-205
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• 1978

발효유 원료유중에 항생물질이 함유되어있을 경우 이것이 발효유 제조에 미치는 영향을 검토하였다. 발효유의 원가유 살균과정, 배양기간, 보존기간중에 있어서 항생물질의 변화를 검토하기 위하여 Bacillus stearothermophilus var. calidolactis C 953을 사용한 cylinder plate법으로 penicillin의 역가를 측정하였다. 저온 장시간 $살균(60^{\circ}C,$ 30분) 조건에서는 조금도 불활성화되지 않았으나, 온도를 높이고, 시간을 길게함에 따라 점점 불활화률이 높아져 $고압멸균조건(121^{\circ}C,$ 15분)에서는 약 90% 이상이 불활화되었다. 또 현재 우리나라에서 발효유제조에 사용되고 있는 Lactobacillus casei, Hy3와 Lactoba-cillus bulgaricus Hy4A, Hy4B를 사용하여 $37^{\circ}C에서$ 배양할 경우 배양기간 중에 있어서 penicillin은 2일내에 95% 이상 불활화되었다. 그리고 $보존기간(5^{\circ}C)$ 중에는 phosphate buffer(pH 6.0)와 10% skim milk의 경우에 10일까지도 거의 불활화가 되지 않았으나, 발효유내에서는 5일만에 85% 이상이 불활화된다는 결과를 얻었다. 이와같은 발효유 배양기간과 보존기간 중의 penicillin 불활화의 원인을 규명하기 위하여 각종 유기산의 영향을 조사한 결과(조건 pH.3.30~3.45, 보존온도 $37^{\circ}C),$ 염산과 유산의 경우 24시간, 구연산의 경우 48시간, 초산의 경우 72시간내에 실험에 사용한 penicillin 농도의 99.99%가 불활화되었다. 이러한 결과로 볼 때 유산발효에서 penicillin이 불활화되는 주원인은 발효에 의하여 생성된 유기산에 의한 것으로 추정된다.방식이군이 중지방식이군과 고지방식이군에 비해 혈장내 LCAT 활성이 유의하게9p<0.001) 증가하였다. 3) 간의 콜레스테롤합성 능력은 정어리유군이 다른지방군보다(p<0.001), 무지방식이군이 식이지방첨가군보다(p<0.001), 동물성지방군의 식물성유지군보다 유의하게(p<0.001) 증가하였으나, 식이 지방의 수준에 의한 차이는 나타나지 않았다. 수용성 식이섬유소가 생리져 기능이 거의 비슷하고 무독성이 관찰됨으로써 신갈나무로부터 제조된 수용성 식이섬유소의 제조 방법이 우수하다고 볼 수 있다.있었다.세에 해당되는 중년 여성의 에너지, 단백질, 철분 섭취량을 권장량과 비교하여 보면, 각각 74.8$\pm$12.6%, 94.6$\pm$26.4% 및 64.5$\pm$14.1%로 당뇨군 (각각 112.8$\pm$28.5%, 157.8$\pm$68.2%, 92.8$\pm$21.7%)에 비해 유의하게 낮았고 정상군과는 유의한 차이를 보이지 않았다.상고나성이 있었다. 혈중 호모시스테인 농도는 질병의 위험요인으로서 뿐 아니라 대사적으로 밀접하게 연관된 비타민 영양상태의 biomarker로서도 그 영향력이 크다고 할 수 있다. 따라서 성별에 다른 다양한 연령집단에서 건강한 일반인과 심혈관계 질환자 등을 대상으로 호모시스테인과 비타민 영양상태에 대한 연구가 체계적으로 이루어 져야 할 것이다.태를 보다 효율적으로 증진시킬 수 있는 대안이 마련되어져야 한다고 사료된다.$\ulcorner$순응$\lrcorner$의 범위를 벗어나지 않는다. 그렇기 때문에도 $\ulcorner$순응$\lrcorner$과 $\ulcorner$표현$\lrcorner$의 성격과 형태를 외형상으로 더욱이 공간상에서는

• Journal of Food Hygiene and Safety
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• v.37 no.2
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• pp.97-106
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• 2022

Listeria monocytogenes (L. monocytogenes) is one of gram-positive foodborne pathogens with a very high fatality rate. Unlike most foodborne pathogens, L. monocytogenes is capable of growing at low temperatures, such as in refrigerated foods. Thus, various physical and chemical prevention methods are used in the manufacturing, processing and distribution of food. However, there are limitations to the methods such as possible changes to the food quality and the consumer awareness of synthetic preservatives. Thus, the aim of this study was to evaluate the anti-listeria activity of lactic acid bacteria (LAB) isolated from kimchi and characterize the bacteriocin produced by Lactococcuslactis which is one of isolated strains from kimchi. The analysis on the anti-listeria activity of a total of 36 species (Lactobacillus, Weissella, Lactobacillus, and Lactococcus) isolated from kimchi by the agar overlay method revealed that L. lactis NJ 1-10 and NJ 1-16 had the highest anti-listeria activity. For quantitatively analysis on the anti-listeria activity, NJ 1-10 and NJ 1-16 were co-cultured with L. monocytogenes in Brain Heat Infusion (BHI) broth, respectively. As a result, L. monocytogenes was reduced by 3.0 log CFU/mL in 20 h, lowering the number of bacteria to below the detection limit. Both LAB strains showed anti-listeria activity against 24 serotypes of L. monocytogenes, although the sizes of clear zone was slightly different. No clear zone was observed when the supernatants of both LAB cultures were treated with proteinase-K, indicating that their anti-listerial activities might be due to the production of bacteriocins. Heat stability of the partially purified bacteriocins of NJ 1-10 and NJ 1-16 was relatively stable at 60℃ and 80℃. Yet, their anti-listeria activities were completely lost by 60 min of treatment at 100℃ and 15 min of treatment at 121℃. The analysis on the pH stability showed that their anti-listeria activities were the most stable at pH 4.01, and decreased with the increasing pH value, yet, was not completely lost. Partially purified bacteriocins showed relatively stable anti-listeria activities in acetone, ethanol, and methanol, but their activities were reduced after chloroform treatment, yet was not completely lost. Conclusively, this study revealed that the bacteriocins produced by NJ 1-10 and NJ 1-16 effectively reduced L. monocytogenes, and that they were relatively stable against heat, pH, and organic solvents, therefore implying their potential as a natural antibacterial substance for controlling L. monocytogenes in food.