• Biotechnology and Bioprocess Engineering:BBE
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• 제3권1호
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• pp.44-47
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• 1998

Maximum cellulase production was sought by comparing the activities of the cellulases produced by different Trichoderma reesei strains and Aspergillus niger. Trichoderma reesei Rut-C30 showed higher cellulase activity than other Trichoderma reesei stains and Aspergillus niger that was isolated from soil. By optimizing the cultivation conditions during shake flask culture, higher cellulase production could be achieved. The FP(filter paper) activity of 3.7U/ml and CMCase (Carboxymethylcellulase) activity of 60U/ml were obtained from shake flask culture. When it was grown in 2.5L fermentor, where pH and DO levels are controlled, the enzyme activities were 133.35U/ml (CMCase) and 11.67U/ml(FP), respectively. Ammonium sulfate precipitation method was used to recover enzymes from fermentation broth. The dried cellulase powder showed 3074.9U/g of CMCase activity and 166.7U/g of FP activity with 83.5% CMCase recovery.

• Natural Product Sciences
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• 제3권2호
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• pp.106-107
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• 1997

Indole-3-methylethanoate was isolated for the first time form natural source i.e. from the leaves of Camellia sinensis (L.) O. Kuntz and fully characterized by physical and chemical evidence, the biological activity of the compound was studied by wheat coleoptile bioassay which showed growth promoting activity.

• Safety and Health at Work
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• 제8권4호
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• pp.393-397
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• 2017

Background: It has been suggested that engaging technology can empower individuals to be more proactive about their health and reduce their health risks. The aim of the present intervention was to study the effects of technology-aided testing and feedback on physical activity and biological age of employees in a middle-sized enterprise. Methods: In all, 121 employees (mean age $42{\pm}10$ years) participated in the 12-month three-arm cluster randomized trial. The fitness measurement process (Body Age) determined the participants' biological age in years. Physical activity was measured with the International Physical Activity Questionnaire Short Form. Results: Physical activity did not change during the intervention. Biological age (better fitness) improved in all groups statistically significantly (p < 0.001), but with no interaction effects. The mean changes (years) in the groups were -2.20 for the controls, e2.83 for the group receiving their biological age and feedback, and -2.31 for the group receiving their biological age, feedback, and a training computer. Conclusion: Technology-aided testing with feedback does not seem to change the amount of physical activity but may enhance physical fitness measured by biological age.

• The Plant Pathology Journal
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• 제22권3호
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• pp.289-294
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• 2006

Two isolates of mucous bacteria, mc75 and pc78, were isolated from fungal culture plate as culture contaminants with an interesting swarming motility. Both isolates were identified as Pseudomonas fluorescens based on microscopy, biochemical analysis, Biolog test and DNA sequence analysis of the 16S rRNA gene. Both strains have the exactly the same 16S rRNA gene sequences, and yet their biological control activity were not identical each other. In vitro analysis of antagonistic activity of two isolates against several plant pathogenic fungi indicated that both produced diffusible and volatile antifungal compounds of unknown identities. Treatment of the bacterial culture of P. fluorescens pc78 and its culture filtrate exhibited a strong biological control activity against rice sheath blight in vivo among six plant diseases tested. More effective disease control activity was obtained from treatment of bacterial culture than that of culture filtrate. Therefore, in addition to antifungal compound and siderophore production, other traits such as biofilm formation and swarming motility on plant surface may contribute to the biological control activity of P.fluorescens pc78 and mc75.

• Journal of Microbiology and Biotechnology
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• 제17권4호
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• pp.650-654
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• 2007

In our previous work, a method of pretreating lipase was developed to prevent loss of its activity during covalent immobilization. In this study, Rhizopus oryzae lipase was pretreated before immobilization and then immobilized on a silica gel surface. The effects of the various materials and conditions used in the pretreatment stage on the activity of immobilized lipase were investigated. Immobilized lipase pretreated with 0.1% of soybean oil had better activity than those pretreated with other materials. The optimal temperature, agitation speed, and pretreating time for lipase pretreatment were determined to be $40^{\circ}C$, 200rpm, and 45min, respectively. The activity of immobilized soybean oil pretreated lipase was 630U/g matrix, which is 20 times higher than that of immobilized non-pretreated lipase. In addition, immobilized lipase activity was maintained at levels exceeding 90% of its original activity after 10 reuses.

• Applied Biological Chemistry
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• 제46권3호
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• pp.155-164
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• 2003

Biological Hammett Equation에 기초하여 Hansch-Fujita식으로 제안된 정량적인 구조 활성상관(QSAR) 기법 (Sung, Nack-Do (2002) Development of new agrochemicals by quantitative structure-activity relationship (QSAR) methodology. Kor. J. Pestic. Sci. 6: 166-174, 231-243 및 7: 1-11)에 따른 새로운 농약의 탐색과 개발에 관련하여 1990년도를 전후한 국내에서 이루어진 QSAR 기법중 주로 2D QSAR기법의 활용연구 현황에 대하여 조명하였다.

• Journal of Microbiology
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• 제41권1호
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• pp.22-27
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• 2003

A lipase from Aeromonas sp. LPB 4, a psychrotophile isolated from a sea sediment was purified and characterized. The lipase was purified 53.5 fold to a homogeneous state by acetone precipitation and QAE sephadex column chromatography and its molecular weight was determined to be 50 kDa by SDS-PAGE. The enzyme exhibited maximum activity at 10$^{\circ}C$ and was stable at temperatures lower than 50$^{\circ}C$. This lipase favored substrates containing medium carbon chain of acyl group, while too low and high carbon chain decreased its activity. The lipolytic activity of purified lipase was slightly increased by the addition of 0.1% detergent, but decreased by 1% of detergent. Butanol severely decreased the lipase activity while methanol increased the activity about 15%.

• Journal of Microbiology and Biotechnology
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• 제16권7호
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• pp.1041-1046
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• 2006

Selenium-containing peptide (selenium peptide) was produced by autolysis of total proteins of Saccharomyces cerevisiae grown with inorganic selenium. Selenium peptide exhibited antioxidant activity as a glutathione peroxidase (GPx) mimic, and its activity was dependent on the hydrolysis methods. The GPx-like activity of the hydrolyzed selenium peptide increased 2.7-folds when digested by protease, but decreased by acid hydrolysis. During the autolysis of the yeast cell, the GPx-like activity and selenium content increased 4.3- and 2.3-folds, respectively, whereas the average molecular weight (MW) of selenium peptide decreased 70%. The GPx-like activity was dependent on the MW of selenium peptide and was the highest (220 U/mg protein) at 9,500 dalton. The maximum GPx-like activity (28,600 U/g cell) was obtained by 48 h of autolysis of the cells, which were precultured with 20 ppm of selenate. Selenium peptide showed little toxicity, compared with highly toxic inorganic selenium. These results show the potential of selenium peptide as a nontoxic antioxidant that can be produced by simple autolysis of yeast cells.

• Journal of Microbiology
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• 제41권4호
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• pp.289-294
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• 2003

Gelatinase is a proteolytic enzyme that hydrolyzes gelatin. Gelatinolytic activity was detected from culture broths of Streptomyces griseus IFO13350 and HH1 by paper disc assays on 0.5% agar plates containing 1% gelatin. The concentrated extracellular protein from the S. griseus was analyzed by SDS polyacrylamide gel, and two proteins, with molecular weights of 30 and 28 kDa, respectively, were identified to have gelatinase activity by gelatin zymography. The protein with a molecular weight of 28 kDa was confirmed to be S. griseus trypsin (SGT). The effects of metal ions and metal chelators on the protease activity of the SGT were studied. Of the metal ions tested, only manganese was found to enhance the protease activity, 2.6 times, however, $Co^{2+},\;Cu^{2+},\;and\;Zn^{2+}$, and metal chelators, such as EDTA and EGTA, inhibited the SGT activity. When the protease activity of the SGT was measured at various pHs, in the presence of 5 mM $MnCl_2$, its highest activity was at pH 11.0, whereas only 60% of the maximum activity was observed between pHs 4.0 and pH 6.0, and almost 80% activity between pHs 7.0 to pH 10.0. The protease activity was measured at various temperatures in the presence of 5 mM $MnCl_2$. The SGT was found to be stable up to $60^{\circ}C$ for 30 min, while only 16% of the enzyme activity remained at $60^{\circ}C$, and at $80^{\circ}C$ almost all the activity was lost. The optimal temperature for the protease activity was $50^{\circ}C$.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2003년도 생물공학의 동향(XIII)
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• pp.672-673
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• 2003