• 한국미생물·생명공학회지
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• 제31권1호
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• pp.63-68
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• 2003

구성적으로 고온내성과 고온발효능을 가지고 있는 Saccharomyces cerevisiae KNU5377 균주는 YPD 배지에 0.5M NaCl을 첨가한 YPDS 배지에서 자란 경우, 일반 YPD에서 성장한 지수성장기 세포에서 약 80%의 생존율을 보이던 고온내성이 20% 생존율을 보이고, 또한 약 8.5%정도의 알코올 생산량을 보이던 것이 6%수준으로 감소하여 대조균주와 유사한 고온발효능과 고온내성도를 보였다. 즉 구성적으로 아주 높은 내성도와 발효능을 가진 이 균주가 대조균주와 동질화되는 현상이 발생한 것이다. 이것은 S. cerevisiae KNU5377의 고온내성과 고온발효능의 원인이 이 균주 특유의 NaCl adaptation 과정과 밀접한 관계가 있음을 암시하는 것이다. 또한 이 균주의 고온발효능은 heat adaptation에 의해서 그 알코올 생산량의 증가폭 또한 대조 균주보다 2배 이상을 보이므로, 이 S. cerevisiae KNU5377가 가지는 생리적 특징이 최소한 대조균주에 비해서는 heat adaptation의 효과를 더 크게 볼 수 있는 시스템을 가지고 있음을 알 수 있었다. 이러한 특성들은 그 균주 특이적 현상의 원인을 밝힐 수 있는 중요한 단서로서 활용이 가능하며, 이 균주가 충분히 고온하에서의 알콜 생산 균주가 될 수 있음을 보여주고 있다.

• 한국축산식품학회지
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• 제36권4호
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• pp.469-475
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• 2016

This study examined the relationship between NaCl sensitivity and stress response of Listeria monocytogenes. Nine strains of L. monocytogenes (NCCP10805, NCCP10806, NCCP10807, NCCP10808, NCCP10809, NCCP10810, NCCP10811, NCCP10920 and NCCP 10943) were exposed to 0%, 1%, 2% and 4% NaCl, and then incubated at 60℃ for 60 min to select strains that were heat-sensitized (HS) and non-sensitized (NS) by NaCl exposure. After heat challenge, L. monocytogenes strains were categorized as HS (NCCP 10805, NCCP10806, NCCP10807, NCCP10810, NCCP10811 and NCCP10920) or NS (NCCP10808, NCCP10809 and NCCP10943). Total mRNA was extracted from a HS strain (NCCP10811) and two NS strains (NCCP10808 and NCCP10809), and then cDNA was prepared to analyze the expression of genes (inlA, inlB, opuC, betL, gbuB, osmC and ctc) that may be altered in response to NaCl stress, by qRT-PCR. The expression levels of two invasion-related genes (inlA and inlB) and two stress response genes (opuC and ctc) were increased (p<0.05) in NS strains after NaCl exposure in an NaCl concentration-dependent manner. However, only betL expression was increased (p<0.05) in the HS strains. These results indicate that the effect of NaCl on heat sensitization of L. monocytogenes is strain dependent and that opuC and ctc may prevent NS L. monocytogenes strains from being heat sensitized by NaCl. Moreover, NaCl also increases the expression of invasion-related genes (inlA and inlB).

• KSBB Journal
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• 제16권6호
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• pp.626-631
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• 2001

본 연구에서 L. crispatus KLB46을 저온 전처리함으로서 제제화 과정에 받게 되는 얼림과 녹임, 건조 스트레스뿐만 아니라, 여러 다른 환경 스트레스에 대한 내성이 증진된다는 것을 확인하였다. 그리고 내성 증진에 신규 단백질 합성이 필요함을 확인하였으며 나아가, 저온 충격 유전자 (csp)를 확인하였다. 따라서 이 균주를 제제화 하기 위한 방법으로 저온 전처리를 이용할 경우 생균력 유지에 큰 효과를 얻을 수 있다고 사료된다.

• 한국자기공명학회논문지
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• 제21권3호
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• pp.102-108
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• 2017

Escherichia coli responds to ever-changing external and internal stresses by rapidly adjusting its physiology for better survival. This adjustment occurs at all levels including metabolites as well as mRNAs and proteins. Although there has been many reports describing E. coli's adaptation to various stresses regarding transcriptomics or proteomics, only a few investigations have been reported regarding this adaptation viewed from metabolites' perspective. We applied four different types of stresses at four different doses as imposed by NaCl, sorbitol, ethanol, and pH to investigate the similarities or differences among the stresses, and which stress causes the largest perturbation of the metabolite composition. We profiled the metabolites under such external stresses by using two-dimensional NMR spectroscopy and identified 39 metabolites including amino acids, sugars, organic acids, and nucleic acids. According to our statistical analysis, the osmotic stress caused by sorbitol differentiated itself from others, while NaCl showed the largest dose dependent metabolic perturbations. We hope this work will form a foundation on which an approach to a successful protein production is systematically provided by a favorable metabolic environment by imposing proper external stresses.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.152-152
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• 2017

Plants exposed to environmental stress for long durations often can adapt to stress conditions with improved tolerance. Moreover this acquired tolerance to stress can be retained even after reverting to destressed growth conditions, which is known to stress memory. In these adaptation and stress memory processes, epigenetic regulation, such as DNA methylation and histone modifications play a key role. Here, we showed that regenerated rice plants from embryogenic callus exposed to gradually increasing NaCl concentrations (up to 120 mM NaCl) acquired salt tolerance and their enhanced tolerance are inherited to subsequent generations. The rice plants (R0) regenerated from rice callus under saline conditions were transplanted into normal paddy field and R1 seeds were harvested. These R1 seeds displayed higher germination rate on MS medium containing 100mM NaCl than wild-type. The callus derived from R1 seeds showed better growth than control callus on high salinity medium. And the salt-adapted R1 plants exhibited higher chlorophyll contents and also higher $K^+/Na^+$ ratio than wild-type rice under saline conditions. The results indicated that rice plants successfully adapted to saline growth conditions during regeneration on high salt medium and moreover this acquired tolerance to salt stress was inherited subsequent generation.

• The Korean Journal of Ecology
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• 제25권2호
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• pp.101-107
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• 2002

건조 및 염 환경에 우점종으로 분포하고 있는 명아주과 식물의 염 및 무기 영양 농도에 다른 생리적 적응특성을 비교하기 위해 염습지에 널리 분포하는 칠면초(Suaeda japonica), 퉁퉁마디(Salicornia herbacea) 및 채소로 재배되는 근대(Beta vulgaris var. 챠침)를 재료로 하여 염 농도 (0, 50, 100, 200, 400 mM NaCl) 및 무기 영양염 농도(Hoagland 용액의 1/1, 1/5, 1/10배액)를 달리하여 식물의 엽생장과 질소, 무기 이온, 전기 전도도 및 삼투조절물질의 변화를 정량적으로 분석하였다. 3종 명아주과 식물은 무기영양 및 염의 농도변화에 대해 식물체에 상당량의 염을 축적하였으며, 높은 내염성 기구를 통해 400 mM NaCl 처리에서도 현저히 생장을 촉진하는 호염성의 퉁퉁마디와 200 mM NaCl 처리까지 약간의 생장 촉진을 보이는 근대 및 높은 내염성을 가지면서 50 mM NaCl 이상 처리구에서 약간의 생장 저해를 보이는 칠면초의 세가지 염내성의 종 특성을 보였다. 무기이온의 동태에 있어서 3종 식물은 무기 영양 및 염 농도와 무관하게 체내에 소량의 수용성 Ca을 함유하였고(<10μM/g plant water), K이온은 염 농도가 증가함에 다라 다소 감소하였으며, Na+과 Cl-은 배지의 무기 영양과는 무관하게 염 농도가 증가함에 따라 현저히 증가하였다. 총 질소 함량은 무기 영양 및 염의 농도가 증가함에 따라 감소하는 경향을 보였으며, 전기 전도도와 삼투몰농도는 무기영양보다 염의 농도가 증가함에 따라 증가하는 양상을 보였다. Glycinebetaine과 proline의 함량은 각각 0.2∼2.5 μM/g plant water와 0.1 ∼ 0.6 ㎛M/g plant water였고, 50mM NaCl 처리구에서 최대치를 보였다.

• Ocean and Polar Research
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• 제26권3호
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• pp.433-438
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• 2004

Stress response to the seawater acclimation in coho salmon (Oncorhynchus kisutch) smolt was investigated. Salt concentration of rearing water was gradually increased for 3 days from freshwater to seawater (30 ppt salt level). The changes of serum concentrations of cortisol as a primary stress indicator, and as secondary indicators, glucose (GLC), lactate (LAC), triglyce.ide (TG), cholesterol (CHOL), sodium ion $(Na^+)$, chloride ion $(Cl^-)$ and enzyme activities (alanine aminotransferase, ALT: aspartate aminotrasferase, AST; lactate dehydrogenase, LDH) were quantified during the acclimation experiment. Among them, cortisol, LAC, TG, CHOL, ALT, AST concentrations showed rapid increase at the first exposure to the 10ppt salt level (day 1), and began to decrease to the constant values after day 2 of adaptation at 20ppt salt level. However, LDH concentration tended to decrease during the whole experimental period. $Na^+\;and\;Cl^-$ showed slight decrease at day 1, and increased to a little bit higher values after day 2 rather than those in freshwater. All the fishes started on taking a food after day 4 of seawater adaptation. From these results, to reduce osmotic shock inducible stress to fish in seawater acclimation, gradual increase of salt levels is recommended.

• 한국발생생물학회지:발생과생식
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• 제24권3호
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• pp.215-224
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• 2020

Seawater adaptability of steelhead trout increases along with the increase in the size of the fish, independent of parr-smolt transformation. Three 96 h seawater challenge tests were conducted to determine the size at which seawater adaptability of steelhead trout develops. Plasma Na⁺ and Cl^- levels, moisture content, gill Na⁺/K⁺ ATPase activity, and mortality during the 96 h after direct transfer to seawater (32 ppt) were determined. Plasma Na⁺ and Cl^- levels in 50 g fish continuously increased during the 96 h after the transfer to seawater (p<0.05), but the levels in 100 and 150 g fish leveled off after 24 h (p<0.05). Both 100 and 150 g size steelhead trout maintained muscle moisture content (%) better than 50 g size fish (p<0.05). Gill Na⁺/K⁺ ATPase activity in the 100 g size group increased in a time-dependent manner after transfer to seawater (p<0.05), whereas activity in the 50 and 150 g sizes did not increase (p>0.05), for which a possible explanation was discussed. A mere 2.6% mortality in both the 50 and 150 g size groups was observed. In conclusion, the current results indicate that 50 g size steelhead trout did not show development of a high level of hypoosmoregulatory capacity, whereas fish in the 100 and 150 g size groups showed a high level in our experimental conditions. Therefore, the steelhead trout larger than a 100 g size is recommended for transfer to seawater culture.

• 한국양식학회지
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• 제18권2호
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• pp.69-75
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• 2005

One 30-day feeding trial was conducted to examine the effects of dietary salt on seawater adaptability of rainbow trout (Onchorhynchus mykiss) fed three experimental diets containing 0% (control), 4% and 8% salt. The experimetal period included 30 days of feeding trial in freshwater, 3 days of the step by step seawater acclimation with-out feeding diets, and 21 more days of seawater adaptation period (not with all experimental fish) with feeding the basal diet. Growth rates from triplicate groups were determined fur 30 days of feeding trial. Blood samples were taken at the begining and at the end of feeding trial, and 3 times (on 1st, 4th and 8th day) of the seawater adaptation period. Daily survival rates of duplicate groups from three experimetal treatments were recorded for 21 days of the seawater adaptation period. Total average initial and final fish weight were $149.5{\pm}7.6\;and\;187.1{\pm}7.6g$. Feed efficiency of fish fed diets containing 4% and 8% salt were significantly better than those of fish fed the control diet. Average cumulative survival rates were 72, 80 and 88% from the control, 4% and 8% salt diets, respectively. Pulse rate per minutes decreased with dietary salt level. Serum $Na^+\;and\;Cl^-$ concentrations of fish fed 4% and 8% salt diets were significantly higher than those of fish fed the control diet (P<0.05), however, the concentrations were stabilized after 8 days of seawater adaptation. Serum cortisol, glucose, cholesterol and tryglyceride concentrations, and the osmorality of fish decreased with dietary salt level, these values were significantly lower than those of fish fed the control diet. These results indicated that the dietary supplementation of salt could have advantages for seawater adaptability of rainbow trout.

• The Korean Journal of Ecology
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• 제25권3호
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• pp.171-177
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• 2002

건조 및 염 환경에 우점종으로 분포하고 있는 명아주과 식물의 염 및 무기 영양 농도에 따른 생리적 적응특성을 비교하기 위해 염습지에 널리 분포하는 칠면초(Suaeda japonica), 퉁퉁마디(Salicornia herbacea) 및 채소로 재배되는 근대(Beta vulgaris var. cicla)를 재료로 하여 염 농도(0, 50, 100, 200, 400 mM NaCl) 및 무기영양염 농도(Hoagland 용액의 1/1, 1/5, 1/10배액)를 달리하여 식물의 엽생장과, 질소, 무기 이온, 전기 전도도 및 삼투조절물질의 변화를 정량적으로 분석하였다. 3종 명아주과 식물은 무기영양 및 염의 농도변화에 대해 식물체에 상당량의 염을 축적하였으며, 높은 내염성 기구를 통해 400 mM NaCl 처리에서도 현저히 생장을 촉진하는 호염성의 퉁퉁마디와 200 mM NaCl 처리까지 약간의 생장 촉진을 보이는 근대 및 높은 내염성을 가지면서 50 mM NaCl 이상 처리구에서 약간의 생장 저해를 보이는 칠면초의 세가지 염내성의 종 특성을 보였다. 무기이온의 동태에 있어서 3종 식물은 무기 영양 및 염 농도와 무관하게 체내에 소량의 수용성 Ca을 함유하였고($<10{\mu}M/g$ plant water), K이온은 염 농도가 증가함에 따라 다소 감소하였으며, $Na^+$과 $Cl^-$은 배지의 무기 영양과는 무관하게 염 농도가 증가함에 따라 현저히 증가하였다. 총 질소 함량은 무기 영양 및 염의 농도가 증가함에 따라 감소하는 경향을 보였으며, 전기 전도도와 삼투몰농도는 무기영양보다 염의 농도가 증가함에 따라 증가하는 양상을 보였다. Glycinebetaine과 proline의 함량은 각각 $0.2{\sim}2.5{\mu}M/g$ plant water와 $0.1{\sim}0.6{\mu}M/g$ plant water였고, 50 mM NaCl 처리구에서 최대치를 보였다.