• Journal of Microbiology and Biotechnology
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• v.20 no.3
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• pp.518-524
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• 2010

A mannanase gene (man26B) was obtained from a sea bacterium, Paenibacillus sp. BME-14, through the constructed genomic library and inverse PCR. The gene of man26B had an open reading frame of 1,428 bp that encoded a peptide of 475- amino acid residues with a calculated molecular mass of 53 kDa. Man26B possessed two domains, a carbohydrate binding module (CBM) belonging to family 6 and a family 26 catalytic domain (CD) of glycosyl hydrolases, which showed the highest homology to Cel44C of P. polymyxa (60% identity). The optimum pH and temperature for enzymatic activity of Man26B were 4.5 and $60^{\circ}C$, respectively. The activity of Man26B was not affected by $Mg^{2+}$ and $Co^{2+}$, but was inhibited by $Hg^{2+},\;Ca^{2+},\;Cu^{2+},\;Mn^{2+},\;K^+,\;Na^+$, and $\beta$-mercaptoethanol, and slightly enhanced by $Pb^{2+}$ and $Zn^{2+}$. EDTA did not affect the activity of Man26B, which indicates that it does not require divalent ions to function. Man26B showed a high specific activity for LBG and konjac glucomannan, with $K_m,\;V_{max}$, and $k_{cat}$ values of 3.80 mg/ml, 91.70 ${\mu}mol$/min/mg protein, and 77.08/s, respectively, being observed when LBG was the substrate. Furthermore, deletion of the CBM6 domain increased the enzyme stability while enabling it to retain 80% and 60% of its initial activity after treatment at $80^{\circ}C$ and $90^{\circ}C$ for 30 min, respectively. This finding will be useful in industrial applications of Man26B, because of the harsh circumstances associated with such processes.

• Analytical Science and Technology
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• v.13 no.2
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• pp.151-157
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• 2000

Effects of acids and pre-reductants in the analysis of arsenic have been studied by hydride generation-atomic absorption spectrometry. The analytical results were strongly dependent on the acid concentrations. All the pre-reductants was very effective to observe the arsenic signal at strong acid concentrations (3 M-5 M). However, at the low acid condition (${\leq}0.1M$), L-cysteine only showed a reasonable effect on the absorption signal. When the sample was treated with the nitric acid, absorption signal was unstable and was also decreased. Although interference effects were observed from metal ions such as $Cr^{6+}$ and $Br^{5+}$ at low acid condition, the generation of hydride could be increased by the strong acid condition.

• Microbiology and Biotechnology Letters
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• v.22 no.5
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• pp.507-514
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• 1994

Acetyl xylan esterase was produced by E. coli HB101 harboring a recombinant plasmid pKMG6 which contained the estI gene of Bacillus stearothermophilus. The maximum production was observed when the E. coli strain was grown at 37$\circC for 12 hours in the medium containing 0.5% acetyl xylan, 1.0% tryptons, 1.0% sodium chloride, and 0.5% yeast extract. The esterase produced was purified to homogeneity using a combination of ammonium sulfate fractionation, DEAE Sepharose CL-6B ion exchange chromatography and Sephacryl S-200 gel filtration. The native enzyme had an apparent molecular mass of 60 kd and was composed of two identical subunits of 29 kd. The N-terminal amino acid sequence of the polypeptide was Ala-X-Leu-Gln- Ile-Gln-Phe-X-X-Gln. The acetyl esterase displayed a pH optimum of 6.5 and a temperature opti- mum of 45$\circC. The heavy metal ions such as Ag$^{++}$, Hg$^{++}$ and Cu$^{++}$ inhibited nearly completely the activity of the esterase, and no specific metal ion was found to be required for the enzyme activity. The enzyme readily cleaved MAS, $\beta$-D-glucose pentaacetate, $\alpha$-naphthyl acetate, $\rho$-nitrophenyl acetate as well as acetyl xylan, but had no activity on $\rho$-nitrophenyl propionate, $\beta$-nitrophenyl butyrate or $\beta$-nitrophenyl valerate. The Km and Vmax values for MAS were 2.87 mM and 11.55 $\mu$mole/min, respectively. Synergistic behavior was demonstrated with a combination of xylanase and esterase from B. stearothermophilus in hydrolyzing acetyl xylan.

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.236-245
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• 1993

Single crystals, SbSI : V, SbSeI : V, BiSI : V, BiSeI : V, SbSI : Cr, SbSeI : Cr, BiSI : Cr, BiSeI : Cr, SbSI : Ni, SbSeI : Ni, BiSI : Ni, and BiSeI : Ni were grown by the vertical Bridgman method. It is found that the grown single crystals have an orthorhombic structure and the indirect optical transitions. The temperature dependence of energy gap shows the two reflection point related with the phase transitions and is well fitted with Varshni equation in the continuous region. The optical absorption peaks due to the doped impurities (V, Cr and Ni) are respectively attributed to the electron transitions between the split energy levels of $V^{+2}$, $Cr^{+2}$ and $Ni^{+2}$ ions sited at $T_d$ symmetry of the host lattice.

• Korean Journal of Food Science and Technology
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• v.11 no.1
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• pp.42-49
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• 1979

In order to evaluate the utility of the anthocyanins of Amaranthys tricolor L. as an edible pigment, the present study was undertaken to investigate the effects of pH. temperature, ascorbic acid, sugars and their degradation products, quercetin, thiourea, sodium pyrophosphate and metal ions on the stability of the anthocyanins in the model systems. The results obtained from this study were as follows. 1. The degradation of total anthocyanins was retarded as the pH levels decreased from 8.0 to 1.0. At pH 1.0, however. the initial degradation reaction proceeded faster than at pH 2.0 to 3.0 2. On heating in buffered aqueous solution at $80^{\circ}C$, the total anthocyanin content was higher at pH 2.0 than other pH levels. Increasing the storage temperature accelerated greatly the pigment degradation. In darkness at $40^{\circ}C$, after 10 days, only 19% of the original amount was left, while at $2^{\circ}C$, under the same conditions of storage, approximately 90% of the pigment was retained. The half-life of the pigment, 63.0 days at $2^{\circ}C$, shortened to 1. 7 days at $40^{\circ}C$. 3. An increase in ascorbic arid concentration from 0. 15 to 0.50 mg/ml lowered the anthocyanin retention. 4. There was no significant difference between glucose and fructose in anthocyanin degradation effect. Furfural was more effective than other sugar degradation products, formic acid or levulinic acid in accelerating anthocyanin breakdown. 5. Neither quercetin nor sodium pyrophosphate had a protective effect on the anthocyanins in the presence of ascorbic acid, while, in the systems 0.5 or 1 mg/ml of thiourea with $150{\;}{\mu}g/ml$ of ascorbic acid, the loss of anthocyanins was significantly reduced. 6. Both mercuric and cupric ions in 30 ppm greatly accelerated anthocyanin degradation.

• Journal of Life Science
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• v.18 no.6
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• pp.789-795
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• 2008

To study the possible use of probiotics in fish farming, we evaluated antagonism of antibacterial strain Bacillus amyloliquefaciens H41 against the fish pathogenic bacterium Vibrio anguillarum NCMB1. The purification of growth inhibition factor produced by B. amyloliquefaciens H41 was achieved by obtaining supernatant of this bacterium. The growth inhibition factor was purified to homogeneity by 70% ammonium sulfate precipitation, DEAE-sephadex A-50 ion exchange chromatography, sephadex G-200 gel filtration column chromatography, and sephadex G-50 gel filtration column chromatography with 40.8 fold of purification and 2.9% yield. The molecular weight of the purified growth inhibition factor was 48 kDa as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis. The optimum pH and temperature for the growth inhibition factor were pH 7.5 and $30^{\circ}C$, respectively. The activity of growth inhibition factor was enhanced slightly by some metal ions, such as $Mg^{+2}$, $Mn^{+2}$, but was inhibited by the addition of $Co^{+2}$, $Hg^{+2}$, $Zn^{+2}$ and $Ag^{+2}$. NaCl stability of the growth inhibition factor was observed with 50% residual activity at 3% NaCl concentration. Toxicity test showed that the purified B. amyloliquefaciens H41 growth inhibition factor did not affect the live of Japanese flounder (Paralichthys olivaceus) and the effectiveness was 78% of residual lethality compared to commercial antibacterial agents.

• Korean journal of applied entomology
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• v.13 no.1 s.18
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• pp.1-10
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• 1974

The activities of pectolytic and cellulolytic enzymes produced from slices of ginseng root infected with Cylindrocarpon destructains(Zins.) Scholtern were proportional to each concentration and reaction time. Activities of cellulase(Cx), endo-polygalacturonase(endo-PG), endo-polymethylg-alacturonase(endo-PMG), exo-polygalacturonase(exe-PG), and exe-polymethylgalacturonase(exo-PMG) were maximum on the 4th day after inoculation. No endo-PG and endo-PMG were detected at the first and second days, while exo-PG exo-PMG were active. On the 6th day, all pectic enzymes were completely lost, whereas Cx remained at a high concentration. pH optima of Cx, endo-PG, endo-PMG, exo-PG, and exo-PMG were 6.0, 5.5, 8.0, 7.0 to 7.5, and 8.5, respectively. Temperature optima of Cx, endo-PG, endo-PMG exo-PG, and exo-PMG were $66^{\circ}C\;53^{\circ}C\;41^{\circ}C\;37^{\circ}C\;and\;40^{\circ}C$, respectively. Cx was only inhibited by $0.05M\; Hg^{++}$ among 16 ions tested. Inhibitory effects of ions on pectolytic enzymes varied, however$M Fe^{+++}\;and\;0.05M\;Al^{+++}$ were the best in general. Among 8 fungicides, none of them inhibited all the enzymes studied at $0.1\%$, active ingredients. Exo-PG were highly inhibited by all of the fungicides, of which difolatan was the most inhibitory to all the pectic enzymes. $Ca^{++}\; at\; 0.02M\; and\;Fe^{+++}\;at\;0.02M$ completely inhibited all the pectolytic enzymes, and Cx was inhibited $30\%$ and $70\%$ at the same concentration, respectively Formalin almost inhibited exo-PG and exe-PMG at $0.8\%$ but not the other enzymes especially Cx. Difolatan at $0.8\%$ inhibited all the enzymes concerned above $80\%$. The cellulolytic and pectolytic enzymes of C. destructans must be closely associated with the ginseng root rot and should be inhibited to control the disease effectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.273-288
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• 1991

To elucidate the physiological and biochemical differences between chondrichthyes and osteichthyes, the properties of the specific digestive enzymes in cat-shark, Cephaloscyllium umbratile, and mackerel, Scomber japonicus, were studied. Homogenous trypsin proved through the disc-electrophoresis, SDS-PAG electrophoresis and gel filtration was obtained from the pancreas of cat-shark by $50-70\%$ saturated ammonium sulphate fractionation, DEAE-Sephadex A-50 column chromatography, benzamidine-Sepharose 6B affinity chromatography and Sephadex G-75-120 gel filtration. Two types of trypsins were also obtained from the pyloric caeca of mackerel by $30-70\%$ saturated ammonium sulphate fractionation and the slightly modified procedure from the method adopted in the purification of cat-shark trypsin. The two trypsins, designated trypsin A and B, were proved their homogeneity by disc- and SDS-PAG electrophoresis and gel filtration. The molecular weights of the trypsins were estimated to be 31,700 for cat-shark trypsin, 30,000 for mackerel trypsin A and 29,000 for mackerel trypsin B by SDS-PAG electrophoresis, but those were estimated to be 21,500 for cat-shark trypsin, 23,700 for mackerel trypsin A and 21,500 for mackerel trypsin B by gel filtration. The trypsins exhibited their optimum conditions at pH 9.0 and on temperature ranged from $45^{\circ}C\;to\;50^{\circ}C$ for cat-shark, and at pH 8.0 and a temperature of $50^{\circ}C$ for mackerel trypsin A and B, respectively. The cat-shark trypsin was stable at pH 10.0 and the temperature below $10^{\circ}C$, whereas the mackerel trypsin A and B, were stable in the range over pH 7.0 to pH 9.0 below $10^{\circ}C$ and at pH 8.0 below $35^{\circ}C$, respectively. The mackerel trypsins were severely inhibited by some heavy metal ions such as $Ag^{2+},\;Cu^{2+}\;and\;Hg^{2+}$ compared to cat-shark trypsin. All of the enzymes were also inhibited by antipain, leupeptin, TLCK(tosyllysine chloromethyl ketone) and SBTI(soybean trypsin inhibitor) remarkably. The inhibitory effects of PMSF(phenylmethane sulphonylfluoride), DFP(diisopropyl fluorophosphate) and benzamidine were indicated that these enzymes belong to serine-proteases.

• Applied Biological Chemistry
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• v.24 no.4
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• pp.260-266
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• 1981

Some properties of cellulase and xylanase produced from Pleurotus ostreatus 301 and Lentinus edodes 3-1 during its growth in rice straw medium were investigated. The cellulase activities of P. ostreatus 301 and L. edodes 3-1 were increased in proportion to substrate concentration within 0.6% and 0.8%, respectively, and xylanase activities of two strains were increased within 1%. The reducing sugar production of cellulase and xylanase in two strains were proportionaly increased until 30 min. and 60 min. respectively. The opium pH for cellulase activities of P. ostreatus 301 and L. edodes 3-1 were pH 4.0 and pH 4.5, respectively, and xylanase activities of two strains were pH 5.0. The stable pH range for cellulase activities of P. ostreatus 301 was within 4.0 to 6.0 and L. edodes 3-1 was within 3.0 to 5.0, Xylanase activities of P. ostreatus 301 was within 4.5 to 6.0 and L. edodes 3-1 was within 3.5 to 6.0. The optium temperature for cellulase activities of P. ostraeatus 301 and L. edodes 3-1 were $40^{\circ}C$ and $50^{\circ}C$, respectively, but xylanase activities of P. ostreatus 301 and L. edodes 3-1 were $50^{\circ}C$ and $45^{\circ}C$, respectively. Thermal stability of enzymes were below of optimum temperature and these were mostly inactivate at $70^{\circ}C$ for 10 min of the metalic ions tested, cellulase activities of L. edodes 3-1 was increased by $Co^{++},\; Mg^{++}$ at the concentration of $10^{-2}M$, but were greatly inhibited by $Hg^{++},\;Cu^{++}$ in two strains. Xylanase activities were increased by $Ca^{++},\;Co^{++},\;Mg^{++}$ and $Cd^{++}$ but was greatly inhibited by $Hg^{++}$.

• Journal of Environmental Health Sciences
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• v.23 no.3
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• pp.27-39
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• 1997

This study, collaborated Gifu University, Japan, was performed to analyze chemical pollutants and microorganism and to clarify the distribution of sulfate-reducing bacteria and their insolubilization of heavy metal ions in leachates sampled seasonally between 1994 and 1996 from Nanjido waste landfill site, sampled 4 times between 1995 and 1996 from Pusan and Daejeon waste landfill site, and sampled 1 time between 1992 and 1994 from Hokkaido, Nagoya, Osaka and Hukuoka waste landfill site in Japan. The results were as follows: 1. The temperatures of internal leachate and leachate effluent were 40$\circ$C and 30$\circ$C, respectively, and the pH values of both leachates were about 8.0 at Nanjido waste landfill site. The concentration of SO$_4^{-2}$ gradually increased with the degree of stabilization and that of NO$_3$-N was detected in a part of sampling sites at one and half years, and in all sampling sites at 3 years after completion of landfill. 2. The organic substances in leachate of Nanjido waste landfill site decreased with the degree of stabilization and they were very fluctuated with measuring point and time. The concentration of organic substance and heavy metals in internal leachate were higher than in leachate effluent and those of Cd, Hg, and Pb were lower than detection limit except a part of samples in 1996. 3. APCs in internal leachate and leachate effluent were not much different and the minimum of APCs in internal leachate and leachate effluent were $1.0\times 10^4$/ml and $4.0\times 10^1$/ml, respectively. 4. The maximums of SRBs in Nanjido, Pusan, and Daejeon waste landfill site were 9180 MPN/ml, 24000 MPN/ml, and 348 MPN/ml, respectively and the maximum of SRBs in Japan waste landfill site was 9300 MPN/ml. 5. During 2-week-SRB culture, the values of MPN were high at 50$\circ$C for initial culture period and at 30$\circ$C for last culture period. MPN started to appear at first day and rapidly increased between 7th day and 9th day. 6. Cadmium and copper were insolubilized by SRB within 6 hr and iron and zinc were done within 48 hr. The rates of insolubilization of Cd, Cu, Fe, Zn, T-Cr were 100%, 99.5%, 95.0%, 99.8%, 16.1% after 48 hr treatment with SRB, respectively.