• Journal of Dairy Science and Biotechnology
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• v.37 no.1
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• pp.49-56
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• 2019

Vulvovaginal candidiasis is a major urogenital infection in women. Lactobacilli are important in maintaining vaginal health. In the present study, the effect of heat adaptation at $47{\sim}52^{\circ}C$ prior to heat stress at $60^{\circ}C$ in improving the viability of Lactobacillus salivarius MG242 was examined. L. salivarius MG242 has antifungal effects against Candida albicans. Heat-adapted cells had a higher survival rate than non-adapted cells during the subsequent heat stress. When chloramphenicol was added during the adaptation process, heat tolerance was abolished, suggesting the involvement of de novo protein synthesis with the heat adaptation of L. salivarius MG242 strain. Exopolysaccharide quantification and scanning election microscopy did not reveal any appreciable changes during heat adaptation. The antifungal activity of L. salivarius MG242 against C. albicans was maintained during the heat adaptation. These results suggest that heat adaptation can be applied for the development of probiotic products using L. salivarius MG242 to improve its stress tolerance during processing.

• KSBB Journal
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• v.18 no.4
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• pp.294-300
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• 2003

In the previous study, we have isolated several vaginal lactobacilli from Korean woman and selected one of them (KLB12) for further study, which was indentified as Lactobacillus fermentum by sequence analysis of 16S rRNA gene. Formulated L. fermentum KLB12 can be used for ecological treatment of bacterial vaginosis. For pharmaceutical formulation, the spray-drying process is required where stress such as high temperature is routinely applied. In this study, we found that heat stress at 60$^{\circ}C$ for 20∼30min reduced the viable cell population of KLB12 by 10$\sub$6/～10$\sub$9/. However, adaptation of KLB12 cells at 52$^{\circ}C$ made them more thermotolerant upon exposure to 60$^{\circ}C$. The level of thermal protection in RSM (reconstituted skim milk) by adaptation in acid (pH 5), cold (4$^{\circ}C$), ethanol (3％), NaCI (0.3M) was also examined. Although not as efficient as the homologous stress, adaptations in both cold and NaCI gave considerable cross protection against heat stress. When chloramphenicol was added during heat adaptation, adaptation effect was abolished. This suggests that de novo protein synthesis is necessary during the adaptation process. Important changes in proteome during heat adaptation was examined with two-dimensional gel electrophoresis.

• KSBB Journal
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• v.29 no.2
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• pp.81-86
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• 2014

Lactobacilli, the dominant species of microorganisms in the vaginal flora of healthy women, play important roles to prevent bacterial vaginosis and other sexually transmitted diseases. In this study, we carried out studies on stress adaptation prior to various stress treatment. We found that heat or salt adapted KLB46 showed higher cell viability than non adapted upon heat stress at $60^{\circ}C$ for 20 min. When chloramphenicol was added during the adaptation process, heat tolerance was abolished. This result suggested that de novo protein synthesis was essential during adaptation.

• Journal of Korean Biological Nursing Science
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• v.16 no.3
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• pp.164-172
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• 2014

Purpose: The purpose of this study was to identify the effects of an extreme heat Adaptation Program on the blood pressure, stress response, self-efficacy, and knowledge of management of hypertension and extreme heat of patients who suffered from hypertension. Methods: A quasi-experimental study with a non-equivalent control group pretest-posttest design was used. The data collection period was between July 2 and August 20, 2012. Thirty-seven patients participated in the study (18 in the experimental group and 19 in the control group). Data were analyzed using $X^2$-test, t-test, and Cronbach's alpha coefficients with SPSS/WIN 19.0. Results: Patients who participated in the program showed statistically significant improvements in systolic blood pressure (SBP), self-efficacy, and knowledge of management of hypertension and extreme heat. Conclusion: The results indicate that this extreme heat adaptation program can be utilized for patients suffering from hypertension in order to reduce their SBP and to increase self-efficacy and knowledge of management of hypertension and extreme heat. Therefore, it is recommended that this program be used for elderly patients suffering from chronic disease.

• Journal of Microbiology and Biotechnology
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• v.30 no.5
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• pp.739-748
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• 2020

In this study, a method of heat adaptation was implemented in an attempt to increase the upper thermal threshold of two Streptococcus thermophilus found in South Korea and identified the alterations in membrane fatty acid composition to adaptive response to heat. In order to develop heat tolerant lactic acid bacteria, heat treatment was continuously applied to bacteria by increasing temperature from 60℃ until the point that no surviving cell was detected. Our results indicated significant increase in heat tolerance of heat-adapted strains compared to the wild type (WT) strains. In particular, the survival ratio of basically low heat-tolerant strain increased even more. In addition, the strains with improved heat tolerance acquired cross protection, which improved their survival ratio in acid, bile salts and osmotic conditions. A relation between heat tolerance and membrane fatty acid composition was identified. As a result of heat adaptation, the ratio of unsaturated to saturated fatty acids (UFA/SFA) and C18:1 relative concentration were decreased. C6:0 in only heat-adapted strains and C22:0 in only the naturally high heat tolerant strain were detected. These results support the hypothesis, that the consequent increase of SFA ratio is a cellular response to environmental stresses such as high temperatures, and it is able to protect the cells from acid, bile salts and osmotic conditions via cross protection. This study demonstrated that the increase in heat tolerance can be utilized as a mean to improve bacterial tolerance against various environmental stresses.

• Journal of Environmental Impact Assessment
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• v.21 no.1
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• pp.71-80
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• 2012

Against the backdrop of the clear impact of climate change, it has become essential to analyze the influence of climate change and relevant vulnerabilities. This research involved evaluating the impact of heat waves in Seoul, from among many local autonomous bodies that are responsible for implementing measures on adapting to climate change. To carry out the evaluation, the A1B scenario was used to forecast future temperature levels. Future climate scenario results were downscaled to $1km{\times}1km$ to result in the incorporation of regional characteristics. In assessing the influence of heat waves on people-especially the excess mortality-we analyzed critical temperature levels that affect excess mortality and came up with the excess mortality. Results of this evaluation on the impact of climate change and vulnerabilities indicate that the number of days on which the daily average temperature reaches $28.1^{\circ}C$-the critical temperature for excess mortality-in Seoul will sharply increase in the 2050s and 2090s. The highest level of impact will be in the month of August. The most affected areas in the summer will be Songpa-gu, Gangnam-gu, and Yeongdeungpo-gu. These areas have a high concentration of residences which means that heat island effects are one of the reasons for the high level of impact. The excess mortality from heat waves is expected to be at least five times the current figure in 2090. Adaptation plan needs to be made on drawing up long-term adaptation measures as well as implementing short-term measures to minimize or adapt the impact of climate change.

• Journal of Korea Planning Association
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• v.53 no.7
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• pp.87-107
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• 2018

With more than 10 million inhabitants, in particular, Seoul, the capital of Korea, has already experienced a number of severe heat wave. To alleviate the potential impacts of heat wave and the vulnerability to heat wave, policy-makers have generally considered the option of heat wave strategies containing adaptation elements. From the perspective of sustainable planning for adaptation to heat wave, the objective of this study is to identify the elements of vulnerability and assess heat wave-vulnerability at the dong level. This study also performs an exploratory investigation of the spatial pattern of vulnerable areas in Seoul to heat wave by applying exploratory spatial data analysis. Then this study attempts to select areas with the relatively highest and lowest level of adaptive capacity to heat wave based on an framework of climate change vulnerability assessment. In our analysis, the adaptive capacity is the relatively highest for Seongsan-2-dong in Mapo and the relatively lowest for Changsin-3-dong in Jongno. This study sheds additional light on the spatial patterns of heat wave-vulnerability and the relationship between adaptive capacity and heat wave.

• Microbiology and Biotechnology Letters
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• v.31 no.1
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• pp.63-68
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• 2003

Saccharomyces cerevisiae KNU5377 is a constitutively thermotolerant, fermentative strain at high temperatures over 4$0^{\circ}C$. The exposure to 0.5 M NaCl caused S. cerevisiae KNU5377 to be lost its constitutive thermotolerance. Furthermore, the NaCl adaptation beyond 0.3 M during the overnight culture forced the strain-specific fermentation ability of S. cerevisiae KNU5377 to be disappeared. However, these phenomena did not occur in the reference, Saccharomyces cerevisiae ATCC24858. As a result, this adaptation led both strains to show the closely similar thermotolerance level and alcohol fermentation ability, implying the NaCl adaptation eliminated its strain-specific characteristics of S. cerevisiae KNU5377 Therefore it indicated that the superior intrinsic characteristics of S. cerevisiae KNU5377 must be related to the NaCl adaptation. On the other hand, the heat adaptation elevated alcohol productivity for both strains, but surprisingly did it for KNU5377 at the rate of two times higher than the reference's one; this suggests that KNU5377 possesses more efficient system enough to cause the difference. Consequently, these characteristics of S. cerevisiae KNU5377 must be interesting targets for further study to understand on how KNU5377 could acquire the constitutive thermotolerance and the outstanding fermentative capacity at high temperatures.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.249-252
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• 2009

Two-dimensional gel electrophoresis (2-DE) was employed to assess the thermo-tolerance characteristics of Bifrdobacterium infantis ATCC 27920 to mild heat adaptation. When exposed to various heat levels, pH, and hydrogen peroxide ($H_2O_2$) stress conditions, B. infantis ATCC 27920 exhibited high level of stress resistance. Under mild-heat treatment ($46^{\circ}C$), no significant change in viability level was observed after 2 hr. Interestingly, improved viability was observed in mild-heat adapted ($46^{\circ}C$ for 1 hr) cultures exposed to $55^{\circ}C$, in comparison to control experiments. Viability was not affected by pH, bile, and $H_2O_2$ stress conditions. 2-DE analysis revealed those mild-heat adaptation up-regulated 4 proteins and down-regulated 3 proteins. Among these protein spots, isopropyhnalate dehydratase (leuD), glycosyltransferase (glgA), and ribosomal protein L5 (rp1E) were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALD1-TOF/MS).

• KSBB Journal
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• v.16 no.6
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• pp.626-631
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• 2001

Lactobacilli have been considered to play important roles in the health of human vagina. They secrete inhibitory substances to prevent vaginal infection by pathogenic organisms. In a previous study, we have isolated several lactobacilli from Korean woman and one of them (KLB46) was selected and indentified as Lactobacillu crispatus which showed high antimicrobial activity. In this study. cold adaptation prior to subsequent stresses exposure was examined whether L. crispatus KLB46 maintain the viability better than the non-adapted calls under stresses. For pharmaceutical formulation, the lyophilization process is required where stresses such as freezing/thawing and dehydration are routinely applied. Formulated L. crispatus KLB46 can be used for ecological treatment of bacterial vaginosis. The response of cold-adapted cells to other environmental stresses such as acid, heat, ethanol, NaCl, and H$_2$O$_2$ was also examined. The results showed that cold-adapted cells maintained higher survival rate compared with the non-adapted cells (freezing-thawing. 3-folds; dehydration: 3-folds; acid, 3-folds; heat, 10-folds). However, we did net observe any positive effect of cold adaptation on other stresses such as ethanol, NaCl and H$_2$O$_2$. When chloramphenicol was added during cold adaptation, adaptation effect was abolished. This confirms that de novo protein synthesis is necessary during the adaptation process. Moreover, we have identified cold shock protein homolog that codes for a major cold shock protein by PCR amplification using degenerate primers.