• Fisheries and Aquatic Sciences
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• 제27권6호
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• pp.379-391
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• 2024

Tocopherol, carotenoids, and chlorophyll are the primary components of the antioxidative response in microalgae. Conditions of stress, such salt stress, can trigger the processes responsible for the accumulation of tocopherol and carotene. It has been found that the most difficult part of culturing microalgae is keeping it affordable. This study investigated the effects of different salt types and concentrations on the amount of α-tocopherol, carotenoid derivatives, and flocculation efficiency of Euglena sp. Cultures of Euglena sp. was developed under salt stress conditions of NaCl 200 mM and KCl 200 mM. UV-VIS spectrophotometry was used to confirm the presence of α-tocopherol and carotenoid derivatives under thirteen days of salt stress testing. Increasing salinity has a significant effect on Euglena sp., causing spherical cell morphologies with aspect ratio 1.385 ± 0.031 for NaCl 200 mM and 1.414 ± 0.040 for KCl 200 mM. Increasing salinity also slowing down development with specific growth rate value of 0.171 ± 0.006 per day and 0.122 ± 0.029 per day for NaCl and KCl 200 mM, respectively. Nevertheless, the amount of α-tocopherol in Euglena sp. increases with a high salt concentration; algal cells flocculated more successfully when increasing the salt concentrations (NaCl 200 mM and KCl 200 mM) was added. Due to the inhibition of photosynthetic activity in salt-stressed cells, the control group exhibited higher levels of carotenoid derivatives (ranging from 0.5-1 ㎍/mL) and pheophytin a and b (0.0062 ± 0.001 ㎍/mL and 0.0064 ± 0.001 ㎍/mL) than the group treated with salt stress. In conclusion, salt stress was an effective way to raises the concentration of α-tocopherol and significantly reduce the expense of harvesting Euglena sp.

• 유기물자원화
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• 제14권2호
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• pp.83-90
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• 2006

음식물 쓰레기로 만든 퇴비 중의 염분함량을 1% 이하로 조절하기 위해 지금까지 여러 가지 방법이 개발되었다. 그러나 이런 방법들은 침출수 과다로 인한 환경오염 또는 높은 설치비 등의 문제를 가지고 있어 실용화에 어려움이 있다. 염분이 충분히 제거되지 않은 음식물 쓰레기로 만든 퇴비를 농지에 사용할 경우 염해로 인한 식물의 성장 장애 및 염류축적이 일어날 수 있다. 본 연구는 음식물 쓰레기 퇴비에 함유된 염분을 $KHSO_5$, $KHSO_4$, $K_2SO_4$로 구성된 삼중염을 이용하여 분해하는 방법이며 기존 화학적 처리방법과 달리 염분을 분해하여 칼륨비료의 원료인 KCl로 전환시켰다. 또한 음식물 쓰레기 퇴비화 발효설비에서 음식물 쓰레기 600톤에 삼중염을 적용해본 결과 발효시의 온도가 평균 $5^{\circ}C$가 상승되었다. 온도상승과 함께 전처리 공정 및 발효공정에서 현저한 악취저감 효과가 나타났으며 이는 삼중염으로 인한 염분함량 감소로 호기성균의 활성화 및 악취원인물질을 효과적으로 제거하기 때문이다.

• 한국가스학회지
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• 제24권5호
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• pp.56-64
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• 2020

해양 가스전의 다양한 생산환경에서 PVCap의 하이드레이트 억제 성능을 평가하고자 PVCap 농도, 과냉각 온도, 염수 농도, MEG 혼합 농도 변화에 따라 하이드레이트 지연시간을 측정하였다. 이를 위해 고압의 하이드레이트 반응 실험 장치를 제작하였으며, 하이드레이트 평형 조건 및 지연시간 측정결과를 선행 실험과 비교함으로써 실험장치의 신뢰성에 대한 타당성을 검증하였다. 과냉각 온도 6.1, 9.2, 12.1℃조건에서 PVCap 농도 0.1~1 wt%의 억제 성능을 분석한 결과, 과냉각 온도가 증가함에 따라 PVCap으로 인한 지연시간이 감소하였다. 염수 농도가 3 wt%에서 7 wt%까지 증가하였을 때, PVCap 폴리머 체인의 구조 저하가 발생하여 PVCap 0.5 wt% 조건에서 최대 78%까지 지연시간이 감소하였다. MEG 10 wt%와 PVCap을 혼합한 HHI(hybrid hydrate inhibitor)의 경우, 아억제(under-inhibition) 영향으로 PVCap 1 wt%에 비해 지연시간의 변화가 크지 않았으나, MEG 20 wt%인 HHI에서는 하이드레이트 억제 효율이 1.7배 증가하였다.

• 한국식품위생안전성학회지
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• 제23권2호
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• pp.91-97
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• 2008

Kimchi is a representative traditional food in Korea and a type of vegetable product that is the unique complex lactic acid fermentation in the world. It can be considered as a unique fermented food generated by various flavors, which are not included in raw materials, that can be generated by mixing and fermenting various spices and seasonings, such as red pepper powder, garlic, ginger, and salted fish, added to Chinese cabbages. Functionalities in Kimchi have been approved through several studies and the probiotic function that is mainly based on lactic acid bacteria including their physical functions in its contents has also verified. Studies on the verification of the safety of Kimchi including its physiological functions have been conducted. In particular, the function of lactic acid bacteria, which is a caused of the fermentation of Kimchi. Although the lactic acid bacteria contributed to the fermentation of Kimchi is generated from raw and sub-materials, the lactic acid bacteria attached on Chinese cabbages has a major role in the process in which the fermentation temperature and dominant bacteria are also related to the process. The salt used in a salt pickling process inhibits the growth of the putrefactive and food poisoning bacteria included in the fermentation process of Kimchi and of other bacteria except for such lactic acid bacteria due to the lactic acid and several antimicrobial substances generated in the fermentation process, such as bacteriocin and hydrogen peroxide. In addition, the carbon dioxide gas caused by heterolactic acid bacteria contributes to the inhibition of aerobic bacteria. Furthermore, special ingredients included in sub-materials, such as garlic, ginger, and red pepper powder, contribute to the inhibition of putrefactive and food poisoning bacteria. The induction of the change in the intestinal bacteria as taking Kimchi have already verified. In conclusion, Kimchi has been approved as a safety food due to the fact that the inhibition of food poisoning bacteria occurs in the fermentation process of Kimchi and the extinction of such bacteria.

• Journal of Microbiology
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• 제37권2호
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• pp.59-65
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• 1999

RecA protein can promote strand assimilation, homologous pairing, and strand exchange. All these reactions require DNA-dependent ATP hydrolysis by recA protein, and the activities of recA protein are affected by the ionic environment. In this experiment, DNA-dependent ATPase activity showed different sensitivity to anionic species. ATP hydrolysis and strand exchange were relatively sensitive to salt in the reactions with NaCl, strongly inhibited at 100 mM NaCl. However, the inhibition by sodium acetate or sodium glutamate was not observed at 50∼100 mM concentration. Addition of sodium glutamate to the standard reaction condition increased the apparent efficiency of ATP hydrolysis during strand exchange. The condition including 50∼100 mM sodium-glutamate might be similar to the physiological condition.

• Journal of Microbiology and Biotechnology
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• 제19권4호
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• pp.346-350
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• 2009

Although salt is known to influence the performance of nitrification significantly, it has not been well reported on how salt affects ammonia-oxidizing bacterial(AOB) community compositions and dynamics in wastewater treatment bioreactors. In this study, these questions were evaluated in a full-scale bioreactor treating saline wastewater. Clone library analysis for the ammonia monooxygenase subunit A gene revealed that AOB belonging to the Nitrosomonas europaea and the N. oligotropha lineages inhabited in the bioreactor. Terminal restriction fragment length polymorphism analysis for monthly samples demonstrated a fluctuation pattern among AOB populations, although AOB within the N. europaea lineage were dominant during the test period. Correlation analysis between patterns of terminal restriction fragments and environmental variables suggested that sodium, chloride, and sulfate were less important; rather, temperature was the most significant factor affecting the AOB community in the bioreactor.

• Journal of Applied Biological Chemistry
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• 제50권2호
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• pp.74-77
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• 2007

Crude extracts of 69 marine organisms (27 salt marsh plants and 42 seaweeds) were screened for the inhibitory activity against the protein tyrosine phosphatase 1B (PTP1) in vitro. The most active extracts were methanol extracts from Derbesia marina (80.6% in inhibitory activity) and Symphycladia latiscula (85.6%) at the concentration of $15{\mu}g/mL$. Methanol extracts of Codium adhaerens and Hisikia fuziformis were moderately inhibitory with 71.2 and 69.1% inhibition, respectively. It was peculiar that only the extracts from seaweeds show inhibitory activity where those from salt marsh plants do not show any significant effect.

• 동아시아식생활학회지
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• 제24권5호
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• pp.641-645
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• 2014

This study was performed to investigate the possibility of using three commercial bifidobacteria as a starter for soybean paste fermentation. In order to determine susceptibility to inhibition by high concentrations of salt in soybean paste, cell growth of three strains in sterilized soybean paste was analyzed. Bifidobacterium breve KCTC 5081 was the most resistant to salt, whereas Bifidobacterium bifidum KCTC 5082 showed low cell viability. Conversion efficiencies from glycoside isoflavone to aglycon isoflavone in soybean paste ranged from 11.3~28.6%, with Bifidobacterium longum KCTC 5734 the best strain. Therefore, B. longum KCTC 5734 may be used as a starter for Cheonggukjang fermentation, which is low-salt fermented soybean paste.

• 한국식품저장유통학회지
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• 제7권2호
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• pp.222-227
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• 2000

Antimutagenic activity of crushed kimchi fermented with starter under various conditions such as temperature(5-20$^{\circ}C$), salt concentration(2-10%), addition rate of starter (0-20%) was investigated. The kimchi was fermented with crushed Chinese cabbage without salting, red pepper powder, crushed garlic, crushed ginger, anchovy juice and starter. Well fermented kimchi juice(fermented at 10$^{\circ}C$ for 15 days) and sterilized radish juice was used as a source of lactic acid bacteria and starter medium, respectively. Antimutagenic activity showed the highest in the crushed kimchi fermented at 15$^{\circ}C$ for 15 days, 4% salt concentration, 5% starter added, respectively. The inhibition rate of mutagenic activity of the kimchi against S. typhimurium TA98 induced by NQO and S. typhimurium TA100 induced by MNNG was 56.41% and 60.11%, respectively. And the inhibition rate of the kimchi juice showed 56-60% per 100ul.

• Journal of Plant Biology
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• 제36권1호
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• pp.113-120
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• 1993

Effects of various NaCl concentrations on salt-tolerant callus of tobacco were investigated. Selection of NaCl-tolerant (S) callus was conducted by subculturing Nicotiana tabacum cv. BY 4 callus in 200 mM NaCl-containing MS medium for more than 18 months. In spite of the long subculture period, characteristics of salt tolerance were maintained very stably. Significant differences were found in ion contents of each callus which was subcultured with treatment of various NaCl concentrations: Na+ and Cl- became higher but Mg2+, Ca2+ and K+ became lower with the increasing external salt contents. Therefore, the ratios of Na+/Ca2+ and Na+/K+ also increased resulting close to those of halophytic property. The contents of chlorophylls and carotenoids in S callus were estimated to 3.1 and 2.9 times more, respectively. than those of non-selected (NS) callus (control). The higher content of external NaCl tended to increase the amount of water soluble proteins and to decrease the amounts of the total sugars, reducing sugars and free amino acids. The activity of peroxidase was increased with higher contents of external NaCl in S callus, but it was maintained at a higher level than S callus at lower NaCl, followed by a subsequent decrease above 80 mM NaCl in NS callus. These results suggest that S callus may have a biological system converting energy source to efficient growth leading to reduction of the growth inhibition under stress environment.