• Microbiology and Biotechnology Letters
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• v.27 no.5
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• pp.354-358
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• 1999

In order to know the antifungal characteristics of saturated fatty acids having 6 to 12 carbons, their minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) were estimated against Saccharomyces cerevisiae. Fatty acids from C6 to C11 exhibited increasing activity with chain length, but C12 fatty acid did not show activity at all. In relation to antifungal modes of actions, fatty acids investigated showed on inhibitory activity toward the plasma membrane H+-ATPase of Saccharomyces cerevisiae. Their inhibitions to the glucose-induced acidification and ATP hydrolysis caused by the proton pump were found to be in common wiht antifungal activities. At the test concentration of 1mM, hexanoic acid (C6) showed the lowest inhibition of about 30%, while undecanoic acid(C11) showed the strongest inhibition of over 90%. In addition, as seen with antifungal activity, the inhibitory activity of dodecanoic acid (C12) was suddenly reduced to less than 50%.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.781-788
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• 2007

The Carbon source to enhance the denitrification is essential matter in the advanced sewage treatment. For the high level of nutrient removal, external carbons such as ethanol, methanol, volatile fatty acids and so on should be needed. In this study, the methods to increase the sludge solubilization and acidification rate were compared with waste activated sludges and food waste leachate. Ultrasonication and acids were used for the pretreatment of organic particles in sludges. As a results, the optimal temperature and HRT were $60^{\circ}C$ and 5 days, respectively. HAc, HPr, HBr, and other VFAs for acid fermentations reduced up to 22, 16, 14, and 48% with HRT reduction. For the increase of solubilization, 28% of solids destruction rate was shown at 0.3 watts/mL.

• Proceedings of KOSOMES biannual meeting
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• 2005.05a
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• pp.119-122
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• 2005

As it is known that the korean coastal fishing areas are getting contaminated by heavy metals from the sediment, the authors conducted the experiments to treat the heavy metals with bioleaching process. As a result, it is found that (1) acidification for the leaching of heavy metals is effectively processed when adding more than $0.3\%$ of sulfur and $0.1\%$ of ferrous sulfate. and (2) copper is rapidly solubilized irrespective of addition of sulfur, while solubilization is not processed even of FeS is added., and (3) bioleaching with sulfur and FeSO4 is possible method to effectively treat the heavy metals form the contaminated sediments.

• Journal of Microbiology
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• v.37 no.1
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• pp.1-9
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• 1999

The Biolog redox technology was carried out for evaluation of acidification effect on microbial communities at each stage of pH gradient microcosm. While the number of heterotrophic bacterial population and activities of extracellular enzyme decreased as the pH decreased, the number of total bacteria in the microcosm was not affected. The average color development of sample at each pH-gradient showed a sigmoidal curve, and at higher pH, more overall color development appeared in Biolog plates. Average color development value in Biolog plates was stabilized at 50 hours as an optimum incubation time. The color production in the Biolog plates was caused by cell density at above pH 5.0, but by cell activity below pH 4.0. Principal component analysis of color responses revealed distinctive patterns among the pH-gradient microcosm samples.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2001.05a
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• pp.185-186
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• 2001

Recently, industrial activities have increased atmospheric concentration of sulfur and nitrogen oxides, resulting in acidification in the environments. In addition, acidification accelerates the mobilization of metals that are toxic to fish and increases their concentrations in the aquatic environment. Increased metals may interfere with reproductive physiology in fish. Al and Cd are such metals that impaired the preduction of Vitellogenin (VTG), a egg yolk precursor proteins. (omitted)

• IMMUNE NETWORK
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• v.20 no.5
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• pp.37.1-37.15
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• 2020

Mycobacterium tuberculosis (Mtb) is an etiologic pathogen of human tuberculosis (TB), a serious infectious disease with high morbidity and mortality. In addition, the threat of drug resistance in anti-TB therapy is of global concern. Despite this, it remains urgent to research for understanding the molecular nature of dynamic interactions between host and pathogens during TB infection. While Mtb evasion from phagolysosomal acidification is a well-known virulence mechanism, the molecular events to promote intracellular parasitism remains elusive. To combat intracellular Mtb infection, several defensive processes, including autophagy and apoptosis, are activated. In addition, Mtb-ingested phagocytes trigger inflammation, and undergo necrotic cell death, potentially harmful responses in case of uncontrolled pathological condition. In this review, we focus on Mtb evasion from phagosomal acidification, and Mtb interaction with host autophagy, apoptosis, and necrosis. Elucidation of the molecular dialogue will shed light on Mtb pathogenesis, host defense, and development of new paradigms of therapeutics.

• Journal of fish pathology
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• v.2 no.2
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• pp.115-124
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• 1989

• Proceedings of the Zoological Society Korea Conference
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• 1996.10a
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• pp.112.2-112
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• 1996

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
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• 1997.10b
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• pp.162.2-162
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• 1997

No Abstract, See Full Text

• Animal cells and systems
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• v.3 no.2
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• pp.153-159
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• 1999

In an artificial pH-gradient batch culture system, the effects of acidification on the species composition of a heterotrophic bacterial community were analyzed. As a result of this study, it was found that total bacteria numbers were not affected by acidification and that the population of hetero-trophic bacteria decreased as pH became lower. The heterotrophic bacteria isolated from the entire pH gradient were 12 genera and 22 species. Among them, 64% were gram negative and 36% were gram positive bacteria. As pH decreased, the distribution rate of gram negative bacteria increased while that of gram positive bacteria decreased. The diversity of genera decreased from 13 to 5 as pH decreased from 7 to 3. The G+C content of all of the 202 isolated strains varied from 22.8 to 77.0%, and increased in interspecies of same genus as pH decreased. As a result of clustering analysis, the diversity index of species ranged from 1.13 to 2.37, and it had lower indices as pH decreased. In order to evaluate the diversity of numbers of sample of different size, a rarefaction method was used to analyze the expected number of species appearance according to pH. The statistical significance of species diversity was verified by the fact that the number decreased at lower pH.