• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.340-349
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• 2009

A CJ9 bacterial strain, which showed antifungal and antibacterial activities, was isolated from meju and identified as Bacillus polyfermenticus based on Gram staining, biochemical properties, as well as its 16S rRNA sequence. B. polyfermenticus CJ9 showed the antimicrobial activity against the various pathogenic molds, yeasts, and bacteria. The antibacterial activity was stable in the pH 5.0~9.0, but the activity was lost at $37^{\circ}C$ for 24 hr. The antifungal activity was stable in the pH range of 3.0~9.0 and reduced at $121^{\circ}C$ for 15 min, but antifungal activity was not completely destroyed. The antibacterial activity was completely inactivated by proteinase K, protease, trypsin, and $\alpha$-chymotrypsin. The antifungal activity was also completely inactivated by protease and $\alpha$-chymotrypsin, and reduced its activity by proteinase which indicated that the antifungal and antibacterial compounds have proteineous nature. The apparent molecular mass of the partially purified antifungal compound, as indicated by using the direct detection method in Tricine-SDS-PAGE, was approximately 1.4 kDa. The molecular mass of the antibacterial compound could not be determined because of its heat-liable characteristic.

• Journal of Microbiology
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• v.39 no.3
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• pp.168-176
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• 2001

Five different types of catalases from photosynthetic bacterium Rhodospirillum rubrum S1 grown aerobically in the dark were found in this study, and designated Catl (350 kDa), Cat2 (323 kDa), Cat3 (266 kDa), Cat4 (246 kDa), and Cat5 (238 kDa). Analysis of native PAGE revealed that Cat2, Cat3, and Cat4 were also produced in the cells anaerobically grown in the light. It is notable that only Cat2 was expressed much more strongly in response to the anaerobic condition. Enzyme activity staining demonstrated that Cat3 and Cat4 had bifunctional catalase-peroxidase activities, while Catl, Cat2, and Cat5 were typical monofunctional catalases. S1 cells grown aerobically in the presence of malate as the sole source of carbon exhibited an apparent catalase Km value of 10 mM and a Vmax of about 705 U/mg protein at late stationary growth phase. The catalase activity of Sl cells grown in the anaerobic environment exhibited a much lower Vmax of about 109 U/mg protein at late logarithmic growth phase. The catalytic activity was stable in the broad range of temperatures (30$\^{C}$-60$\^{C}$), and pH (6.0-10.0). R. rubrum S1 was much more resistant to H$_2$O$_2$in the stationary growth phase than in the exponential growth phase regardless of growth conditions. Cells of stationary growth phase treated with 15 mM H$_2$O$_2$for 1 h showed 3-fold higher catalase activities than the untreated cells. In addition, L-glutamate induced an 80-fold increase in total catalase activity of R. rubrum S1 compared with magic acid. Through fraction analyses of S1 cells, Cat2, Cat3, Cat4 and Cat5 were found in both cytoplasm and periplasm, while Catl was localized only in the cytoplasm.

• Journal of Families and Better Life
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• v.25 no.4
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• pp.113-137
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• 2007

This study examined the characteristics of total consumers' anti-sites on on-line and their changes according to the establishment year of consumers' anti-sites, the activities and the evaluation of consumers' anti-sites and their differences according to the characteristics of consumers' anti-sites. Total 649 consumers' anti sites were analyzed for examining the characteristics of total consumers' anti-sites and 18 anti sites were selected for examining the activities and the evaluations of consumers' anti site. The anti sites were evaluated by the index of using in preceding research. The result showed that about 90% of total consumers' anti-site were not activated, only a few consumers participated even in the activated sites, most activity of the anti-site were operated only on on-line not off-line, over half of anti-sites targeted to the company in the type of the subject of anti-site, and the majority of the external shape of anti-site were cafe. On the change of characteristics according to the opening year, the proportion of cafe and the sites acting on both on-line and off-line were increased year by year. The number of anti-sites was decreased since 2005 and the proportion of highly activated sites was lowest in 2005. On the activity of anti-sites, the number of providing the information were more than the number of presenting the complaint among the bulletin writings. The number of the bulletin writing were more in highly activated sites than in low activated sites. most of highly activated sites were problem solving type compared to the low activated sites. The number of the bulletin writings in company anti-sites were the most among three type of subject of anti-site. The number of the bulletin writings in cafe type were more than in home-page type. On the evaluation of consumers' anti-sites, most of the sites didn't update the notices and provided incomplete information how consumers participated in the protesting movements. The highly activated sites functioned better in most parts in providing a information, connection with other consumer and site manager, management of the site.

• Journal of the Korean School Mathematics Society
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• v.4 no.2
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• pp.75-84
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• 2001

The purpose of this research is to promote the academic achievement motivation and improve problem solving ability in Mathematics. In addition I hope to explore a new teaching method and facilitate students interest in mathmatics. If the teachers utilize an Internet Web Page and exchang information, the interaction activities will allow them to collect and analyse a variety of data. As this teaching method assists students motivation to get the effects of self-regulated learning strategies of students using the internet and their academic achievements and learning attitudes can be explored. The information will be gathered after the students participate in classes which were taught through the Edunet Homepage and the Department of Mathematics Homepage of KongJu National University. The Internet pages focused on the "Function" chapter of the first grade text for students attending middle school. The students were divided into two groups, experimental and comparative. Each group is composed of three levels, high, middle, and low. In the post experimental phase, two tests were administered which measured achievement ability and the learning attitude of the students. The results of the tests were then compared and analyzed. The results were as follows: First, the study demonstrated that self-regulated Learning Starategies towards Academic Achievements and Learning Attitudes were more effective than traditional teaching methods. These methods were significantly effective in the middle level and low level groups. The study demonstrated little to no improvement in the high level groups

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.223-229
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• 2003

The purpose of this work was to perform the characterization of NAD(P)H-nitroreductase isolated from Stenotrophomonas sp. OK-5 capable of degrading 2,4,6-trinitrotoluene (TNT). Initially, NADP(H)-nitroreductase by a series of purification processes including ammonium sulfate precipitation, DEAE-sepharose, andQ-sepharose was prepared. From samples harvested from fraction collector, three different fractions (I, II & III)having the enzyme activity of NAD(P)H-itroreductase were detected. Specific activities of three fractions I, II,and III of NAD(P)H-nitroreductase were determined to approximately 5.06 unit/mg, 4.95 unit/mg and 4.86 unit/mg, and concentrated to 10.5, 9.8, and 8.9-fold compared to crude extract, respectively. Among these three fractions,the fraction I of NAD(P)H-nitroreductase demonstrated the highest specific activity in this experiment. Several factors affecting on the enzyme activity of NAD(P)H-nitroreductase (fractions I, II & III) were investigated.The optimum temperature of all NAD(P)H-nitroreductase (fractions I, II & III) was 30oC, and the optimal pH was approximately 7.5. Metal ions such as Ag+, Cu2+, Hg2+ inhibited approximately 80% enzyme activity of all NAD(P)H-nitroreductase, and the enzyme activities were decreased about 30-40% inhibition in the presence of Mn2+ or Ca2+. However, Fe3+ showed stimulatory effect on the enzyme activity. The molecular weights of NAD(P)H-nitroreductase (fractions I, II & III) were measured about 27 kDa on the SDS-PAGE.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.159-165
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• 1997

We collected 3,237 plant samples, mainly leaves of various trees, from many provinces in Korea and a total of 1,925 Bacillus thuringiensis isolates were obtained and characterized. The isolates were characterized in terms of crystal morphology, PAGE pattern of the toxin proteins, plasmids pattern, biochemical characteristics, and bioassay. The microscopic observation showed that 49.1% of the isolates have bipyramidal shape crystals, 7.1% of spherical shape crystals, 1.4% of rhomboidal shape crystals, and others have small or amorphous inclusions. The insecticidal activities of the spore-crystal mixtures of isolates were tested against Plutella xylostella, Bombyx mori, Culex pipiens, and Agelastica coerulea. Bioassay showed that 51.3% of the isolates were shown to be active; lepidopteran-specific (44.8%), dipteran-specific(4.9%) and coleopteran-specific (1.6%). The remainder(48.8%) did not show any activity against the insects we tested. Interestingly though, some of these non-active isolates were shown to have bipyramidal crystals. By serotyping 22 isolates of our collection, we found that there are various kind of subspecies such as aizawai, amagiens, canadensis, darmstadiensis, galleriae, finitimus, kurstaki, morrisoni and neoleonensis, and three isolates have been classified into a new serotype, H49, and one of them, the type strain, named subsp. muju. From this study it was found that phylloplane is a good source for the isolation of Bacillius thuringiensis, and Bacillus thuringiensis is distributed widely in Korea.

• IMMUNE NETWORK
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• v.10 no.6
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• pp.230-238
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• 2010

Background: The MK1 strain, a novel bacterial isolate from soft-rotten tissue of the Neungee mushroom, produces copious amounts of exopolysaccharide (EPS) in a dextrose minimal medium. This study examined the molecular characteristics and immunomodulatory activity of MK1 EPS. Methods: The EPS in the culture supernatant was purified by cold ethanol precipitation, and characterized by SDS- PAGE/silver staining and Bio-HPLC. The immunomodulatory activities of the EPS were examined using the mouse monocytic cell line, RAW 264.7 cells. Results: The molecular weights of the purified EPS were rather heterogeneous, ranging from 10.6 to 55 kDa. The EPS was composed of glucose, rhamnose, mannose, galactose, and glucosamine at an approximate molar ratio of 1.00 : 0.8 : 0.71 : 0.29 : 0.21. EPS activated the RAW cells to produce cytokines, such as TNF-${\alpha}$ and IL-$1{\beta}$, and nitric oxide (NO). EPS also induced the expression of co-stimulatory molecules, such as B7-1, B7-2 and ICAM-1, and increased the phagocytic activity. The macrophage-activating activity of EPS was not due to endotoxin contamination because the treatment of EPS with polymyin B did not reduce the macrophage-activating activity. Conclusion: The EPS produced from the MK1 strain exerts macrophage-activating activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.6
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• pp.754-760
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• 1996

Effects of washing and additives on the texture of squid surimi gel which has been known to hard to gelation due to high protease activities and many water solubles were studied by SDS-PAGE, compression test, jelly strength and transmission electron microscopy analysis (TEM). Myosin (205 kDa) heavy chain was the major protein in water soluble fractions. It was impossible to make a gel after washing of the minced squid meat. These results suggested that squid (Todarodes pacificus) minced meat does not need a washing for good jelly products. $3.0\%$ of bovine plasma protein (BPP) produced the hardest gel ($16\%$ harder than the control) among the additives including egg white (EW), potato extracts (PE) and transglutaminase-K (TG-K) by compression test (P>0.05). Microstructure of control, $2\%$ EW and $4\%$ TG-K treated gels showed a sponge-like structure with more vacant space. Gels containing $3\%$ BPP formed the most rigid and arranged networks. Those results indicates that poor gel-network formation Was due to the degradation of myofibrillar proteins by proteases contained in the minced meat, which result in non-interlinkage.

• Journal of Microbiology and Biotechnology
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• v.27 no.2
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• pp.277-288
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• 2017

Rhizomucor miehei NRRL 5282 and Rhizopus oryzae NRRL 1526 can produce lipases with high synthetic activities in wheat bran-based solid-state culture. In this study, the purification and biochemical characterization of the lipolytic activities of these lipases are presented. SDS-PAGE indicated a molecular mass of about 55 and 35 kDa for the purified R. miehei and Rh. oryzae enzymes, respectively. p-Nitrophenyl palmitate (pNPP) hydrolysis was maximal at $40^{\circ}C$ and pH 7.0 for the R. miehei lipase, and at $30^{\circ}C$ and pH 5.2 for the Rh. oryzae enzyme. The enzymes showed almost equal affinity to pNPP, but the $V_{max}$ of the Rh. oryzae lipase was about 1.13 times higher than that determined for R. miehei using the same substrate. For both enzymes, a dramatic loss of activity was observed in the presence of 5 mM $Hg^{2+}$, $Zn^{2+}$, or $Mn^{2+}$, 10 mM N-bromosuccinimide or sodium dodecyl sulfate, and 5-10% (v/v) of hexanol or butanol. At the same time, they proved to be extraordinarily stable in the presence of n-hexane, cyclohexane, n-heptane, and isooctane. Moreover, isopentanol up to 10% (v/v) and propionic acid in 1 mM concentrations increased the pNPP hydrolyzing activity of R. miehei lipase. Both enzymes had 1,3-regioselectivity, and efficiently hydrolyzed p-nitrophenyl (pNP) esters with C8-C16 acids, exhibiting maximum activity towards pNP-caprylate (R. miehei) and pNP-dodecanoate (Rh. oryzae). The purified lipases are promising candidates for various biotechnological applications.

• Parasites, Hosts and Diseases
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• v.46 no.3
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• pp.183-186
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• 2008

Helminthic cysteine proteases are well known to play critical roles in tissue invasion, nutrient uptake, and immune evasion of the parasites. In the same manner, the sparganum, the plerocercoid of Spirometra mansoni, is also known to secrete a large amount of cysteine proteases. However, cysteine protease inhibitors regulating the proteolytic activities of the cysteine protease are poorly illustrated. In this regard, we partially purified an endogenous cysteine protease inhibitor from spargana and characterized its biochemical properties. The cysteine protease inhibitor was purified by sequential chromatographies using Resource Q anion exchanger and Superdex 200 HR gel filtration from crude extracts of spargana. The molecular weight of the purified protein was estimated to be about 11 kD on SDS-PAGE. It was able to inhibit papain and 27 kDa cysteine protease of spargana with the ratio of 25.7% and 49.1%, respectively, while did not inhibit chymotrypsin. This finding suggests that the cysteine protease inhibitor of spargana may be involved in regulation of endogenous cysteine proteases of the parasite, rather than interact with cysteine proteases from their hosts.