• Microbiology and Biotechnology Letters
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• 제21권1호
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• pp.30-35
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• 1993

Clp is a relatively abundant ATP-dependent protease found in E. coli. Its specific activity was proportional to the concentration of the limiting amount of Clp A and an excess amount of Clp P, and vice versa. Clp A has an intrinsic ATPase activity that is stimulated by casein, and contains a second site for binding A TP, in addition to the ATPase site. The modification of sulfhydryl groups in Clp A with reagents which have bulky groups such as N-phenylmaleimide led to nullifying both ATPase and protease activity. The same sites were modified by sulfhydryl reagents. It seems that the sulfhydryl groups of Clp A are not directly involved in catalysis. Since non-hydrolyzable analogs of ATP do not activate Clp, ATP hydrolysis may be essential for the proteolytic activity of Clp protease. Clp A and Clp P did not associate in the absence of nucleotide. The results suggest that the activity of the proteolytic component, Clp P, is regulated by the A TP-dependent cycling of Clp A between the activator form and the non-activator form.

• Korean Journal of Microbiology
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• 제51권4호
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• pp.444-447
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• 2015

This study was carried out to determine the antibacterial activity of $SeO_2$ against pathogenic bacteria, methicillin-resistant Staphylococcus aureus (MRSA). Using the disc diffusion method, $SeO_2$ showed higher antibacterial activity against Gram-positive bacteria than Gram-negative bacteria used in this study. Coccus-form bacteria showed much susceptible to $SeO_2$, compared to bacillus-form bacteria. Compared to antibiotics-susceptible S. aureus, antibiotics used in this study showed lower antibacterial activity against MRSA. As $200-500{\mu}g/disc$ of $SeO_2$ was applied, diameters of clear zone for S. aureus and MRSA were 20-32.7 mm and 13.5-17.9 mm, respectively. For MRSA, minimal inhibitory concentration of $SeO_2$ was $40{\mu}g/ml$. When $SeO_2$ was added in culture broth, cell growth of MRSA was inhibited. These results will be applied to determine antibacterial mechanism of MRSA and other pathogenic microorganisms.

• Journal of Life Science
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• 제14권5호
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• pp.815-820
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• 2004

A bacterum containing antitumor activity was isolated from traditional korean food, Jeotgal. Through the 16s rRNA sequence analysis, the bacterium was identitied as a strain of Bacillus subtilis SW-l. The best culture condition for antitumor activity of the bacterium is 3% of soluble starch and 1 % of yeast extract as corbon and nitrogen sources, respectively. Cytotoxicitic concentrations of the culture supernatant of B. subtilis SW-1 against cancer cell lines, A549 and SK-OV3 were 30 ul/ml and 40 ul/ml, respectively, as $IC_{50}$/ values. In DNA fragmentation assay, the culture supernatant showed the programmed cell death (apoptosis) to cause degrading the chromosomal DNA like ladder. Taken together, the culture supernatant of the B. subtilis SW-1 has some possibility to be used as an antitumor agent.

• Journal of Soil and Groundwater Environment
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• 제12권5호
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• pp.54-63
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• 2007

To examine the effects of amendments on heavy mineral oil degradation, a pilot scale experiment was conducted for over 105days. During the experiment, soil samples were collected and analyzed periodically for the determination of residual hydrocarbon and microbial activities. At the end of the experiment, the initial level of contamination ($6,205{\pm}173mgkg^{-1}$) was reduced by $33{\sim}45%$ in the amendment amended soil; whereas only 8% of the hydrocarbon was eliminated in the non-amended soil. Heavy mineral oil degradation was much faster and more complete in compost amended soils. Enhanced dissipation of heavy mineral oil in compost amended soil might be derived from increased microbial activities (respiration, microbial biomass-C) and soil enzyme activity(lipase, dehydrogenase, and FDA hydrolase) were strongly correlated with heavy mineral oil biodegradaton (P < 0.01).

• Journal of the Korean Wood Science and Technology
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• 제31권1호
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• pp.32-40
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• 2003

Antimicrobial and antioxidative activities of heartwood extractives of domestic species were investigated to develop a natural fungicide or preservative. Four lignan derivatives and one taxane were isolated from heartwood of Taxus cuspidata which has been selected due to its high antioxidative activity among the tested species. The chemical structures were identified as : taxusin, isolariciresinol (4, 4', 9, 9'-tetrahydroxy-3', 5-dimethoxy-2, 7'-cyclolignan), lariciresinol (4, 4', 9-trihydroxy-3, 3'-dimethoxy-7, 9'-epoxylignan), taxiresinol (3, 4, 4', 9-tetrahydroxy-3'-methoxy-7, 9'-epoxylignan) and isotaxiresinol (3', 4, 4', 9, 9'-pentahydroxy- 5-methoxy-2, 7'-cyclolignan) on the basis of spectroscopic data and their chemical correlations. According to the results of free radical scavenging activity, isolariciresinol, lariciresinol and isotaxiresinol showed higher radical scavenging activity than those of 𝛼-tocopherol and butylated hydroxytoluene (BHT), the strongest natural and synthetic antioxidants. However, taxusin did not show any free radical scavenging activity. In this regard, it could inferred that high antioxidative activity of extractives of T. cuspidata was derived from isolariciresinol, lariciresinol and isotaxiresinol.

• The Korean Journal of Mycology
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• 제47권3호
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• pp.259-269
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• 2019

Brown spot and sheath rot of rice are caused by fungal pathogens such as Curvularia lunata, Cochliobolus miyabeanus, and Sarocladium oryzae, and cause losses such as reduced rice yield and quality, which is an enormous problem with serious long-term effects. To search biological control agents of phytopathogenic fungi, five kinds of useful Bacillus-like isolates which are excellent in extracellular enzyme activity and produce siderophore were selected from paddy soil of Sunchang in Korea. The selected isolates were tested for excellent antifungal activity against three of the phytopathogenic fungi that frequently occur in rice, and JSRB 177 strain had the most excellent antifungal activity. Based on the experimental results, JSRB 177 is finally selected as a candidate for biological control and identified to Bacillus subtilis through 16S rRNA sequence analysis. In addition, physiological characteristics of JSRB 177 confirmed by analysis of carbohydrate fermentation patterns and enzyme production ability. Based on the above results, JSRB 177 is expected to be used as a biological control agent for the rice pathogenic fungi. In the future, further studies related to industrialization such as port test and establishment of mass production process are needed.

• Korean Journal of Food Science and Technology
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• 제54권1호
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• pp.75-79
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• 2022

Fresh, washed ginseng can be contaminated with microorganism loads as high as 6.5 log CFU/g for total bacteria and 4.3 log CFU/g for mold. The goal of this study was to test eight antibacterial agents on ginseng. Immersing fresh ginseng washed in 1% (w/w) sodium citrate, sodium diacetate, sodium acetate, citric acid, and sodium lactate solution for 1 h resulted in a bactericidal effect of 31.0-97.5% for total bacteria. Among the organic acids, sodium citrate had the best antibacterial effect, with total bacteria reduced from 6.5 log to 4.9 log CFU/g. A 1% (w/w) vitamin B₁ lauryl sulfate solution with surfactant function by hydrophilic and hydrophobic sites can reduce 2.7 log CFU/g (99.8% inactivation) on total bacteria. In the 1% (w/w) calcium oxide solution, total bacteria were reduced by 3 log, showing an excellent inactivation effect of 99.9%. Calcium oxide is a highly useful material for inactivation of microorganisms in fresh ginseng.

• Applied Biological Chemistry
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• 제48권3호
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• pp.201-206
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• 2005

The development of microbial inoculant was conducted using a by-product of oriental herbal medicine. The constituent of the by-product, which was high in organic matter, was 11.3% of crude protein, 5.1% of crude lipid, 49.7% of NDF (neutral detergent fiber), and 33.8% of ADF (acid detergent fiber). Microorganisms isolated from the by-product of oriental herbal medicine were 35 species. Among them, 6 bacterial species, 4 fungal species, 2 actnomycetes species, and 1 yeast species were effective in the utilization of the by-products. The 13 strains screened were tested for the plant growth-promoting effect in soybean seedling. BL-333 strain was found to increase the soybean yield by about 23% as compared with control. The strain BL-333 was identified as Paenibacillus marcerans. P. marcerans BL-333 showed high anti-fungal activities against virulent fungi, especially Fusarium sp. and Collectotrichum sp. Yields of plants which were inoculated with microbial inoculant prepared with P. marcerans BL-333 and by-product of oriental herbal medicine were found to be higher than control by $3{\sim}24%$. The yield was especially promoted in lettuce, radish, chinese cabbage and cucumber plants.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 한국환경과학회 2006년도 추계 학술발표회 발표논문집
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• pp.521-524
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• 2006

본 연구에서는 농업폐기물인 감귤박의 효율적인 재활용 방안으로 고부가가치 제품인 활성탄을 제조하여 이용하는 가능성에 대하여 조사한 결과, 감귤박 폐액으로부터 건조한 시료의 조성은 대부분이 탄수화물로 구성되어 있으며, 또한 이는 미생물, 농약 및 중금속에 오염되지 않은 순수한 천연 재료로 구성되어 있음을 알 수 있었다. 또한 탄화공정 및 활성화공정을 통해 제조된 활성탄의 요오드 흡착능이 KS 규격 중 1급(활성탄 1,100 mg/g 이상)보다 높은 값으로 나타나 공업용 활성탄으로의 활용이 가능할 것으로 사료된다.

• Microbiology and Biotechnology Letters
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• 제7권3호
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• pp.165-173
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• 1979

Recovery component for cell division in UV-irradiated E. coli B was detected with use of the cell extract of E. coli B/r which is a resistant mutant of E. coli B against UV-irradiation. The active substance was non-dialyzable and increased the activity by adding B-NAD remarkably. One more factor for increasing or promoting the restoration recognized was magnesium. Magnesium was effective to stabilze the substance in procedure of isolation. Two active substances were obtained from sucrose gradient centrifugation. One of them was recovred from the botton area and the other from top area just below below surface. the former was not stabilized by magnesium, while the latter stabilized the activity by it remarkably. The former which did not require magnesium was insensitive to protease and the latter which required magnesium was sensitive to it. Both were insensitive to RNase and DNase. Recovery ratio was doubled by using nitrogen gas than aeration in purification process. DNA-ligase less mutant was revealed same activity on it's recovery ratio with the parent strain of E. coli K-12. The active substance stimulating the filament cell may exist as a complex which is inactivated easily in the dissociated state ana requrie B-NAD or magnesium.