• Microbiology and Biotechnology Letters
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• v.38 no.1
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• pp.77-83
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• 2010

The fructus of Crataegus pinnatifida Bunge (CBF) has been used as medicinal and food source in worldwide. In this study, antimicrobial activity of the methanol extract and its sequential organic solvent fractions of CBF against different pathogenic bacteria and fungi, including multidrug resistant Pseudomonas aeruginosa and Candida sp., were investigated. The methanol extract of CBF was active against various gram-positive and gram-negative bacteria, and the ethylacetate and butanol fractions of CBF showed strong antibacterial activity against Listeria monocytogenes, Staphylococcus epidermidis, Staphylococcus aureus, Bacillus subtilis, Salmonella typhimurium, Proteus vulgaris, Escherichia coli and various multidrug resistant Pseudomonas aeruginosa with minimal inhibitory concentration of 1.0~7.5 mg/mL. Also the fractions showed anti-Candida activity against C. albicans, C. kruseis and C. geochares. The methanol extract of CBF and its solvent fractions, except n-hexane fraction, did not show any hemolytic activity against human red blood cell up to $500\;{\mu}g/mL$, respectively. The hemolysis in n-hexane fraction at $500\;{\mu}g/mL$ was less than 9.9%. Our results suggest that the CBF could be developed as a potent antibacterial agent, especially for multidrug resistant Pseudomonas aeruginosa.

• Journal of agriculture & life science
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• v.43 no.3
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• pp.45-54
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• 2009

This study was designed to investigate the effect of cactus (Opuntia ficus-indica var. saboten) extracts on the intestinal bacteria, antioxidative activity and angiotensin -I-converting enzyme(ACE) inhibitory activity. The antimicrobial activities were measured using the 96well-plate method and disc plate method with concentration of 20mg of cactus extract. The stem extract of cactus was inhibitory against Eubacterium limosum, Clostridium perfringens, C. butyricum, C. difficile and Staphylococcus aureus, but was not inhibitory against Bacteroides fragilis, Bifidobacterium bifidum, Lactobacillus acidophilis, Streptococcus thermophilus. The fruit extract of cactus showed no inhibition against Bacteroides fragilis, Bifidobacterium bifidum, Lactobacillus acidophilis, and Streptococcus thermophilis. Their inhibitory activities were not reduced after heat and pH treatment. Antioxidative effects of cactus extracts showed high total polyphenol and flavonoid contents and high activity against free radical DPPH. The stem and fruit extract of cactus showed strong ACE inhibitory activities of 88.8% and 69.2%, respectively. In conclusion cactus (Opuntia ficus-indica var. saboten) extract might be utilized as a functional food material to control intestinal microflora.

• Journal of the Korean Applied Science and Technology
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• v.40 no.5
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• pp.1126-1135
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• 2023

Nine microbial strains were isolated from the byproduct of ginseng processing and field of ginseng cultivation. Two strains among them were confirmed. Phylogenetic analysis of these 𝛽-Glucosidase strains confirmed that strain GYP-1 belongs to the Rhodotorula and strain GYP-3-3 belong to genus Brachybacterium. Rhodotorula sp. GYP-1 was finally selected due to its high biomass production. The 𝛽-Glucosidase activity of Rhodotorula sp. GPY-1 was assessed at 30 ℃, and Higher than 70% of the enzyme activity was maintained at the temperature range of 20-40℃. Although the optimum pH for the highest enzyme activity was pH 5.0, the enzyme was stable throughout the pH range of 5.0-8.0. In addition, Rhodotorula sp. demonstrated antifungal activity against the ginseng root rot disease caused by Botrytis.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.217-226
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• 2009

Allyl isothiocyanate (AIT), the principle ingredient of antimicrobial ingredients from horseradish root, can be prepared from extracts of horseradish root or synthetic method. It is reported that the horseradish root extract has the antimicrobial effect against various oral microorganisms, while there is no further study about the antimicrobial effect against the oral microorganisms of synthetic AIT derived from synthetic method. The aim of the study is to compare the difference of the antimicrobial effect between horseradish root extracts and synthetic AIT. To evaluate the antimicrobial effect, we measured the minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC), and the results are like following. 1. The MIC of horseradish root extract against 7 kinds of oral pathogenic microorganisms is about 117$\sim$1,750 ppm(0.0117$\sim$0.175%), and the MIC of the synthetic AIT is about 344$\sim$3,000 ppm(0.0344$\sim$0.3%), which have the antimicrobial effects against all kinds of microorganisms. 2. The MBC of the horseradish root extracts against the 7 kinds of oral microorganisms is about 625.2$\sim$6,000 ppm(0.06252$\sim$0.6%), and the MBC of the synthetic AIT is about 1,750$\sim$7,000 ppm(0.175$\sim$0.7%), which have the antimicrobial effects against all kinds of microorganisms.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.4
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• pp.375-385
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• 1987

This study was carried out to investigate the effects of pesticides on soil respiration, microflora and enzymes in loam soil, and on pathogenic microorganisms in continuous pepper cropping soil. The results are summarized as follows. No significant effect of pesticides on soil respiration was shown, with the exception of propoxur which slightly increased at $10{\mu}g\;g^{-1}$ treatment. When pesticides were treated, the amount of soil microorganisms generally decreased at the early stage of incubation and the number of microflora was much more decreased at 60-day incubation. When pesticides were treated, the amount of soil enzyme activity was inhibited at the early stage of incubation and gradually recovered at the last stage of incubation. The amount of polygalacturonase activity was increased at the 20-and 30-day incubation in propoxur treatment plot. The amount of ${\beta}$-glucosidase and dehydrogenase activity was increased at 20-and 60-day incubation in carbofuran and acephate treatment plot. The amount of phosphatase activity was increased at 60-day incubation in propoxur and isoprocarb treatment plot. The amount of Fusarium generally decreased in continuous pepper cropping soil, with the exception of isoprocarb and acephate treatment plot which significantly increased. The amount of Pythium increased at 60-day incubation with the exception of captan treatment plot which significantly decreased.

• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.23-33
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• 2023

Sucrose (suc) is a disaccharide that consists of glucose (glu) and fructose (fru). It is a carbohydrate source that acts as a nutrient molecule and a molecular signal that regulates gene expression and alters metabolites. This study aimed to evaluate whether suc-specific signaling induces an increase in bioactive compounds by exogenous suc absorption via roots or whether other factors, such as osmotic stress or biotic stress, are involved. To compare the osmotic stress induced by suc treatment, 4-week-old cultured mugwort plants were subjected to Hoagland nutrient solution with 10 mM, 30 mM, and 50 mM of suc or mannitol (man) for 3 days. Shoot fresh weight in suc and man treatments was not significantly different from the control. Both man and suc treatments increased the content of bioactive compounds in mugwort, but they displayed different enhancement patterns compared to the suc treatments. Mugwort extract treated with suc 50 mM effectively protected HepG2 liver cells damaged by ethanol and t-BHP. To compare the biotic stress induced by suc treatment, 3-week-old mugwort plants were subjected to microorganism and/or suc 30 mM with Hoagland nutrient solution. Microorganisms and/or suc 30 mM treatments showed no difference about the shoot fresh weight. However, sugar content in mugwort treated with suc 30 mM and microorganism with suc 30 mM treatment was significantly higher than that of the control. Suc 30 mM and microorganism with suc 30 mM were effective in enhancing bioactive compounds than microorganism treatment. These results suggest that mugwort plants can absorb exogenous suc via roots and the enhancement of bioactive compounds by suc treatment may result not from osmotic stress or biotic stress because of microorganism, but by suc-specific signaling.

• Korean Journal of Microbiology
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• v.40 no.2
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• pp.94-99
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• 2004

The activities of enzymes that act on oxygen derivatives in Rhodobacter sphaeroides D-230 were investigated under various culture conditions. Intracellular SOD activity from the cells grown in aerobic or anaerobic culture conditions was highest at pH 7.0 and pH 8.0, respectively. On the other hand, extracellular SOD activity was highest at pH 6.0. Catalase activity was highest at neutral pH in both cases. Growth of R. sphaeroides D-230 in aerobic or anaerobic culture conditions was inhibited by methyl viologen. As R. sphaeroides D-230 was cul-tured aerobically, SOD activity was increased about 2-fold by addition of iron ion. But $Mn^+2$ had little effect on the SOD activity of R. sphaeroides D-230 grown in aerobically. NaCN, the inhibitor of Cu$.$Zn-SOD, did not inhibit SOD activity. But, $NaN_3$, the inhibitor of Mn-SOD, inhibited SOD activity in anaerobic cultures con-dition. Therefore, R. sphaeroides D-230 produce Mn-SOD in anaerobic condition, although Fe-Sod is produced in aerobic condition. The activity of catalase was induced by methyl viologen, however, extremely inhibited by NaCN and $NaN_3$.

• Microbiology and Biotechnology Letters
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• v.32 no.3
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• pp.230-237
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• 2004

In this study nitroreductase from Pseudomonas sp. HK-6 capable of degrading 2,4,6-trinitrotoluene (TNT) was characterized. Through a series of purification process including ammonium sulfate precipitation, DEAE-sepharose, and Q-sepharose, three different fractions I, II, and III having the enzyme activity of NTRs whose molecular weights were approximately 27 kDa were detected in fractions from HK-6 cells. Specific activity of the three fractions were approximately 4.85 unit/mg, 5.47 unit/mg, and 5.01 unit/mg, and concentrated to 9.0-, 10.1-, and 9.3-fold compared to crude extract, respectively. The optimal pH and temperature for the three NTR fractions were approximately 7.5 and $30^{\circ}C$, respectively. Metal ions, $Ag^{＋}$ , $Cu^{ 2+}$, $Hg^{2＋}$ inhibited approximately 70% of enzymes activities of all NTR, while $Fe^{2＋}$ did not stimulate or inhibit the activities. Monitoring the effect of chemicals on the enzyme activity revealed that those NTR fractions lost enzyme activity in presence of $\beta$-mercaptoethanol, but were a little influenced by dithiothreitol, EDTA and NaCl. The three NTR fractions demonstrated enzyme activities for nitrobenzene and RDX as well as TNT.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.277-284
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• 2000

In order to investigate the changes of microorganisms, enzyme activity and physiological functionality of five types of traditional Deonjang prepared with various concentrations of Lentinus edodes. The pH of traditional Deonjang was decreased but total acidity was increased during fermentation. NaCl concentrations was increased up to $15.67{\sim}16.02%$ until $30{\sim}45$ days of fermentation but decreased after that. Amino acidity was increased on the traditional Deonjang with increasing the mixture ratio of Lentinus edodes. Reducing sugar content was increased up to $30{\sim}45$ days of fermentation. Total sugar content was increased up to $18.21{\sim}20.57%$ until 30 days of fermentation. As the mixing ratio of Lentinus edodes increased, total sugar also increased. The number of bacteria was highest in all sample after 45 days fermentation, while that of mold was decreased during fermentation. Amylase activity was decreased but protease activity, tyrosinase inhibitor and ACE inhibitor were increased on the traditional Doenjang with increasing the mixture ratio of Lentinus edodes. Antimutagenic activities of traditional Deonjang (10% Cortinellus edodes) were 83.15%, 65.88% against MNNG, NPD on S. typhimutium TA100 and 54.59%, 55.00% against NQO, NPD on S. typhimutium TA98

• Microbiology and Biotechnology Letters
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• v.45 no.1
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• pp.81-86
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• 2017

Alignment of 967 reference sequences of the typical 2-Cys peroxiredoxin family of proteins revealed that 10 amino acids were conserved, with over 99% identity. To investigate whether the conserved aspartic acid residues and serine residue affect the peroxidase and chaperone activity of the protein, we prepared yeast TSA1 mutant proteins in which aspartic acids at positions 75 and 103 were replaced by valine or asparagine, and serine at position 73 was replaced by alanine. By non-reducing SDS-PAGE, TSA1 and the S73A, D75V and D75N mutants were detected in dimeric form, whereas the D103V and D103N mutants were detected in various forms, ranging from high molecular-weight to monomeric. Compared with wild type TSA1, the D75N mutant exhibited 50% thioredoxin peroxidase activity, and the S73A and D75V mutants showed 25% activity. However, the D103V and D103N mutants showed no peroxidase activity. All proteins, except for the D103V and D103N mutants, exhibited chaperone activity at $43^{\circ}C$. Our results suggest that the two conserved aspartic acid residues and serine residue of TSA1 play important roles in its thioredoxin peroxidase activity, and D103 plays a critical role in its chaperone activity.