• Food Science and Preservation
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• v.18 no.1
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• pp.87-90
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• 2011

The methanol extracts of 19 commercial herb medicines was analyzed to antibacterial activities against Edwardsiella tarda, causing several fish diseases. Rhus javanica showed most strong antibacterial activity against E. tarda and Escherichia coli. Methanol extract of R. javanica was further extracted using several organic solvents having different polarity. Extract from ethyl acetate fraction showed strong activity against E. tarda as well as E. coli. Minimal inhibitory concentration, MIC of R. javanica extract was measured and resulted showing $64\;{\mu}g/m{\ell}$ for E. tarda and $256\;{\mu}g/m{\ell}$ for E. coli. It is needed that, from these results, further purification and isolation of reposible compound of these activities and further study on the synergy effect using combination with antibiotics against pathogenic bacteria.

• Microbiology and Biotechnology Letters
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• v.36 no.3
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• pp.195-200
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• 2008

Saxifraga stolonifera (Saxifragaceae) is a perennial herbaceous plant growing in Korea, China, Japan and Russia. The aerial part has been used as herbal medicine for treatment of pneumonia, frostbite, inflammation and microbial infection. In this study, fresh juice and methanol extract were prepared from the aerial part of S. stolonifera, and their antimicrobial, antithrombin, and antioxidant activity were evaluated, respectively. The fresh juice showed weak antimicrobial activity against Proteus vulgaris, Escherichia coli O157:H7 and Candida albicans with ignorable DPPH scavenging activity. But, the methanol extract showed strong antioxidant activity ($IC_{50}$ of $37.5{\mu}g/mL$) with minor, broad-range antimicrobial activity. Antithrombin activities were not observed in fresh juice and extract, up to 1.5 mg/mL. Sequential organic solvent fractionation of methanol extract showed that $IC_{50}s$ of ethylacetate and the butanol fraction were 6.9 and $7.8{\mu}g/mL$, respectively, that is comparable with vitamin C or butylated hydroxytoluene. Analysis of component in extract and fractionates suggested that the antioxidants in fractions are diverse and the active substances have glycosylated phenolic structure. Our results suggest that the aerial part of S. stolonifera could be used as the natural source of potential antioxidant.

• Journal of Life Science
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• v.32 no.10
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• pp.778-783
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• 2022

This study isolated a new agarase-producing bacterium and characterized its agarase. A new agar-degrading strain was isolated from the seashore of Namhae in Gyeongnam province, Korea, and was purely cultured using the Marine Agar 2216 media. The isolated bacterium was identified as Simiduia sp. SH-2 after 16S rRNA gene sequencing. The crude agarase was obtained from the culture medium of the Simiduia sp. SH-2 strain, and the agar-degrading activity was measured. The highest level of activity of the Simiduia sp. SH-2-derived agar-degrading enzyme was 625 U/l. Agar degradation activity was most significant at 40℃ and pH 7.0. Compared to the activity at 40℃, the relative activity was 31% at 20℃ and 71% at 30℃. Compared to the activity at pH 7.0, the relative activity was 94% and 89% at pH 6.0 and pH 8.0, respectively. Residual activity was greater than 96% after exposure to 20℃ and 30℃ for 2 hr and more than 49% after exposure to 40℃ for 2 hr. Simiduia sp. SH-2 was identified as a strain producing β-agarase that creates neoagarooligosaccharides, such as neoagarotetraose and neoagarohexaose. Therefore, the Simiduia sp. SH-2 strain and its β-agarase are expected to be useful functional material producers in the food, cosmetic, and pharmaceutical industries.

• Microbiology and Biotechnology Letters
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• v.35 no.3
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• pp.238-244
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• 2007

To identify the useful biological activities and the superiority in quality of Korean traditional liquors, we prepared the alcohol-free concentrates from different types of commercial traditional liquors, Takju ($T1{\sim}T3$), Yakju/Cheongju ($Y-1{\sim}Y-5$), Fruit wine (F-1) and Soju (S-1, S-2), respectively. We investigate their compositions as well as antimicrobial, antioxidant, and anti-thrombosis activity. Among the 11 traditional liquors, Y-3, Y-4, Y-5 and F-1 showed higher total-polyphenol, total-flavonoids and reducing sugars than the others. The strong antibacterial and anti-thrombosis activities were identified in Y-3, Y-4, Y-5 and F-1, and a minor antioxidant activity was found in F-l. The antibacterial activity of the Y-3, Y-4, Y-5 and F-1 alcohol-free concentrates showed a broad-spectrum, and growth inhibition was found in gram-positive, gram-negative, and ampicillin-resistant bacteria. The sequential solvent fractionation of Y-3, Y-4, Y-5 and F-1, and following analysis showed that ethyl acetate fractions of Y-3, Y-4, Y-5 and F-1 possess strong antibacterial and anti-thrombosis activity. Especially, the ethyl acetate fractions of Y-3, Y-4 and F-1 showed superior anti-thrombosis activity compared than that of aspirin. Our results suggest that the useful substances are produced from substrates and edible plant added during the fermentation, and the Korean traditional liquors could be developed as strong antibacterial and anti-thrombosis agents.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.8
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• pp.1221-1226
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• 2003

High hydrostatic Pressure was applied to Foxtail Millet Yakju to investigate the effects of high pressure on inactivation of microorganisms and enzymes. Total bacteria, lactic acid bacteria and yeast in untreated Yakju were $1.5{\times}$10$^4$,1.9${\times}$10$^4$ and 1.4${\times}$10$^4$ CFU/mL, respectively. Total bacterial count was reduced to 4.1${\times}$l0$^2$ CFU/mL, while lactic acid bacteria and yeast were sterilized completely in Yakju heated at $65^{\circ}C$ for 15 min. Lactic acid bacteria and yeast decreased greatly with the increase of treatment pressure, and were sterilized completely in Yakju treated at more than 300 ㎫ for 10 min/$25^{\circ}C$. Total bacteria were not completely sterilized with pressurization of even 600 ㎫ at room temperature and reduced to 2 log cycle even at $65^{\circ}C$. Total bacteria decreased by 2∼3 log cycle with the increase of treatment time from 10 to 60 min at $25^{\circ}C$/300 ㎫. Pressurization of Yakju caused a partial inactivation of $\alpha$ -amylase and glucosamylase, and the activities of $\alpha$ -amylase and glucoamylase decreased by 18.1% and 21.1%, respectively at $25^{\circ}C$/600 ㎫/10 min. Activities of $\alpha$ -amylase and glucoamylase decreased with the increase of temperature, and 22.2% and 32.1% of the original activity were remained with the treatment at $65^{\circ}C$/300 ㎫/10 min, respectively. Enzyme activities decreased slightly with the increase of treatment time at $65^{\circ}C$/300 ㎫.

• Journal of Life Science
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• v.29 no.12
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• pp.1401-1407
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• 2019

To elucidate whether or not solvent-tolerant bacteria use anti-oxidative defense systems to defend themselves against toxic solvents, oxidative enzyme activity and total anti-oxidative capacity (T-AOC) were investigated in two tolerant strains of Pseudomonas sp. under toluene stress. The superoxide dismutase (SOD) activities of solvent tolerant BCNU 106 exhibited relatively increased levels at a toluene concentration of 100 mg/l, where those of solvent tolerant BCNU 171 increased at 200 mg/l. A greater than three-fold increase in catalase (CAT) levels was observed at concentrations of 200 and 300 mg/l in BCNU 106, and a two-fold increase was monitored at the same concentrations in BCNU 171. High glutathione S-transferase (GST) levels were also observed in the solvent tolerant bacteria. Higher levels of T-AOC was expressed in the solvent tolerant strains than in the ordinary non-tolerant KACC 10266. The highest plateau of SOD in BCNU 171 was observed at 1 hr of toluene exposure. CAT levels plateaued at 1 hr and 14 hr in BCNU 106 and reached the highest plateau at 3 hr in BCNU 171. The highest peak of T-AOC occurred at 9 hr in BCNU 106, and two high peaks occurred in BCNU 171, at 1 hr and at 9 hr of toluene exposure. The solvent-tolerant bacteria showed active antioxidant responses and could survive under harsh environments, including the presence of solvents, through means of antioxidant defense systems.

• Journal of Life Science
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• v.22 no.2
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• pp.266-280
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• 2012

Agar is a cell wall component of macro red algae that can be hydrolyzed by agarase. Agarases are classified into ${\alpha}$-agarase (E.C. 3.2.1.158) and ${\beta}$-agarase (E.C. 3.2.1.81), in accordance with their cleavage pattern, and can be grouped in the glycoside hydrolase (GH)-16, -58, -86, -96, and -118 family according to the amino acid sequences of the proteins. Many agarases and/or their genes have been detected, isolated, and recombinantly expressed from bacteria, and metagenomes have their origins in sea and terrestrial environments. Products of agarases, agarooligosaccharides and neoagarooligosaccharides, represent wide functions such as antitumor, immune stimulation, antioxidation, prebiotic, hepa-protective, antibacterial, whitening, and moisturizing effects; hence, broad applications would be possible in the food industry, cosmetics, and medical fields. In addition, agarases are also used as a tool enzyme for research. This paper reviews the sources, purifications and detection methods, and application fields of agarases. The role of agarases in agar metabolism and the function of their enzymatic products are also surveyed.

• Korean Journal of Microbiology
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• v.54 no.3
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• pp.272-279
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• 2018

This study was carried out to evaluate antimicrobial activity of isolated bacteria from various soils against two strains of Propionibacterium acnes causing acne vulgaris. Among several hundreds of bacterial strains, Paenibacillus elgii DS381, Paenibacillus elgii DS1515, Burkholderia gladioli DS518, and Streptomyces lienomycini DS620 showed high antimicrobial activities against the strains of P. acnes. All isolated bacteria showed 15.5 to 34.3 mm inhibition zone diameter in an agar well diffusion test, and especially DS620 showed the highest inhibition zone diameters (28.3~34.3 mm). Antibacterial substances were expected as lipopeptide (pelgipeptin and paenipeptin) from strains DS381 and DS1515, protease from DS518, and anthracycline antibiotic (daunomycinone) from DS620, and all these showed very low minimum inhibitory concentration [DS381 and DS1515 (0.078 mg/ml), DS518 (0.312 mg/ml), DS620 (0.000078 mg/ml)] against P. acnes. These antibacterial substances could completely kill P. acnes within 24 h in a time-kill assay. These results suggest that antibacterial substances produced by these bacteria may be utilized as useful antimicrobial agent against P. acnes and treatment medicine for acne vulgaris.

• Microbiology and Biotechnology Letters
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• v.34 no.2
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• pp.83-93
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• 2006

In heavily industrialized areas, soil sites are contaminated with high concentrations of heavy metals. These pollutants are highly accumulated to the human body through the food web and cause serious diseases. To remove heavy metals from the soil, a potential strategy is the environmental friendly and cost effective phytoremediation. For the enhancement of remediation efficiency, the symbiotic interaction between the plant and plant growth-promoting rhizobacteria (PGPR) has been attended. In this review, the interaction of the plant and PGPR in the heavy metal-contaminated soil has been reviewed. The physicochemical and biological characteristics of the rhlzosphere can influence directly or indirectly on the biomass, activity and population structure of the rhizobacteria. The root exudates are offered to the soil microbes as useful carbon sources and growth factors, so the growth and metabolism of rhizobacteria can be promoted. PGPR have many roles to lower the level of growth-inhibiting stress ethylene within the plant, and also to provide iron and phosphorus from the soil to plant, and to produce phytohormone such as indole acetic acid. The plant with PGPR can grow better in the heavy metal contaminated soil. Therefore higher efficiency of the phytoremediation will be expected by the application of the PGPR.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.53-59
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• 1996

This study was conducted to evaluate the effects of fowl dzopping. saw dust and rice hall on the soil microflora in vitro. The experiment was designed in seven treatments with the various organic materials and they were only soil (control). soil + fowl dropping (S+F), soil+fowl dropping+rice hull (S+F+R) soil+fowl dropping*saw dust (S+F+S). soil+chemical fertilizer (S+C.F), fowl dropping+rice hull (F+R) and fowl dropping+saw dust (F+S). All the samples of treatment were incubated in $28{\pm}2^{\circ}C$ condition and tested the activity of soil microflora for 84 days The activity of fungi, total bacteria, gram-negative bacteria and actinomycetes showed the highest values at, twenty-first day and the spore-forming bacteria was at forty-second day after incubation. The number of fungi and gram-negative bacteria showed the highest values in the treatment of F+S, the spore-forming bacteria and the actinomycetes were in the S+F+S. and the number of total bacteria was in the F+C.F., but in the treatment of F+R. all the microorganism except fungi showed the lowest values in their numbers. The composition ratio of dead bacteria was higher in the treatments of S+F+R and F+R than in those of others as 70% and 40% respectively. Actinomycetes isolated from the treatments of S+F and S+F+S were identified as Streptomyces sp.. Nocardia sp., Micromonospora sp. Actinomadura sp. and Saccharomonospora sp.