• Korean Journal of Microbiology
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• v.26 no.4
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• pp.355-361
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• 1988

The aims of the present studies were to understand the physiolosical and genetic characters of Streptomyces sp. isolated from soil. It revealed that Streptomyces sp. SMF301 had very fast growth rate and produced extracellular protease and heavily sporulated on rich media. It also showed $\beta$-lactamase activity and pigment production. Nonsporulating mutants were isolated after NTG or acriflavin treatment and their characters were compared with the parent strain. It was found that the mutants obtained by acriflavin treatment and ghier characters were compared with the parent strain. It was found that the mutants obtained by acriflavin treatment lost the pigment formation and $\beta$-lactamase production. Protease actibity of the mutant was lowered and the pH optimum was changed toward neutral. It was found that the changes were resulted from the reduction of alkaline protease biosynthesis in the bald mutant. Therefore it is considered that sporulation, pigment formation, $\beta$-lactamase production, and alkaline protease production in Streptomyces sp. might be controlled with a closely related relationship.

• Journal of the Korean Chemical Society
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• v.23 no.3
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• pp.165-174
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• 1979

A purification technique of glucose oxidase was developed. Using the gluconyl-${\omega}$-aminohexyl Sepharose affinity chromatography, it was partially purified 14.6 folds with 79.7% yield. With the combination of the affinity chromatography and Sepharose 6B gel filtration, the enzyme was purified 27.2 folds from the broth with 74.1% yield. The final purified preparation showed 90.83 U of glucose oxidase activity per mg of protein and a single band by 7% polyacrylamide gel electrophoresis. The absorption spectrum and substrate specificity of the enzyme were studied and the fianal preparation showed the optimal pH between 5.6 and 6.0, the optimal temperature at $40^{\circ}C$, $8.5{\times}10^{-3}M$ of $K_m$ for D-glucose, and 3.43 kcal/mole of the activation energy.

• Microbiology and Biotechnology Letters
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• v.16 no.4
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• pp.259-264
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• 1988

Two forms of extracellular inulinase, designated as PI and PII were detected in the crude enzyme preparation from n species of Pseudomonas isolated from soil. PI and PII were purified to homogeneity by ammonium sulfate fractionation, DEAE Sephadex A-50 chromatography, Sephadex G-100 and Sephadex G-200 gel filteration. Both isoenzymes catalyzed specifically and endowise the cleavage of the $\beta$-2,1-fructofranoside linkage of inulin, and displayed no action upon sucrose, raffinose and levan. The optimal pH values for the PI and PII enzyme were pH 5.5 and 6.0, respectively and the highest activity of the two enzymes was observed at 55$^{\circ}C$. The Km values of PI and PII were calculated to be 2$\times$10$^{-3}$M and 5$\times$10$^{-3}$M, respectively.

• Korean Journal of Food Science and Technology
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• v.12 no.1
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• pp.13-17
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• 1980

A Streptomyces spp. strain SY 79-1 which was capable of producing metal protease was isolated from soil. The optimal pH and temperature of the protease were around pH 8.0 and $45^{\circ}C$, respectively. The stable pH range of the enzyme was between pH 6.0 to 8.0. The enzyme was stable at $45^{\circ}C$, but it lost the activity about 75 % for 5 min and completely for 30 min when it was treated at $60^{\circ}C$. The activity of the enzyme was inhibited by $Hg^{++},\;Cu^{++},\;Ag^{+}$ and activated by $Mg^{++},\;Mn^{++},\;Co^{++},\;but\;Fe^{++},\;Ca^{++},\;Pb^{++}\;and\;Al^{3+}$ did not affect enzyme activity. This enzyme was strongly inhibited by EDTA, but was not inhibited by 2, 4-DNP, ${\rho}$-CMB, ${\varepsilon}$-aminocaproic acid, cysteine, thiourea, citric acid, oxalic acid and sodium arsenate. When cobalt was added to the EDTA-denatured enzyme, the activity of the enzyme was restored.

• Microbiology and Biotechnology Letters
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• v.47 no.3
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• pp.390-400
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• 2019

In this study, strains isolated from soil samples collected from Busan, Changwon, and Jeju Island were examined to verify their abilities of phosphate solubilization and nitrogen fixation, production of indole-3-acetic acid (IAA), siderophore, and 1-aminocylopropane-1-carboxylyic acid (ACC) deaminase in order to select strains that promote plant growth and play a role in biocontrol of pests or pathogens. According to the results of this study, most of the isolated strains were found to have ability of phosphate solubilization, nitrogen fixation, IAA production, siderophore production, and production of ACC deaminase. These isolated strains might help plant growth by directly improving absorption of nutrients essential for phosphate solubilization and nitrogen fixation. In addition, they can promote plant growth and control resistance to plant diseases through extracellular enzyme activity and antifungal activity. In addition, most of the selected strains were found to survive in various environmental conditions such as temperature, salinity, and pH. Therefore, Pseudomonas plecoglossicida ANG14, Pseudarthrobacter equi ANG28, Beijerinckia fluminensis ANG34, and Acinetobacter calcoaceticus ANG35 were finally selected through a comparative advantage analysis to suggest their potential as novel biological agents. Further studies are necessary in order to prove their efficacy as novel biological agents through formulation and optimization of effective microorganisms, their preservation period, and crop cultivation tests.

• KSBB Journal
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• v.22 no.2
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• pp.114-118
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• 2007

In this study, an amylase-producing fungus, strain 15 was isolated from soil in order to saccharify food wastes with cellulolytic and amylolytic enzymes. The amylase production cultures were performed in Mandel's medium with 1% rice straw and 1% paper wastes as carbon sources. The strain produced various cellulolytic (FPase 0.25, xylanase 20.09, CMCase 3.15 U/mL-supernatant) and amylolytic ($\alpha$-amylase 1.20, gluco-amylase 0.70, $\beta$-amylase 2.40 U/mL-supernatant) enzymes in Mandel's medium. In 10 L jar fermenter, maximum amylase and FPase activities, 3.25 and 0.23 U/mL, were obtained when the culture was grown at 30$^{\circ}C$, 200 rpm and 0.6 vvm for 3 days. In 100 mL flask level and 10 L jar fermenter, amylase produced by the strain 15 showed similar cellulolytic and amylolytic enzyme activities with Trichoderma inhamatum KSJ1 isolated from rotten woods by previous researcher. The ability of saccharification to food wastes also showed similar degree. However, the isolate 15 appeared to be yellowish in YMEA plate comparing to Trichoderma inhamatum KSJ1 in greenish.

• Journal of Life Science
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• v.13 no.5
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• pp.618-625
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• 2003

Investigations were carried out to optimize the culture conditions for the production of xylanase by Paenibacillus sp. DG-22, a moderately thermophilic bacterium isolated from timber yard soil. Xylanase production showed a cell growth associated profile. Xylanase activity was found only in the culture supernatant, while $\beta-xylosidase$ activity was mainly associated with the cells. The formation of xylanase activity was induced by xylan and repressed by glucose and xylose. The production profile of xylanase was examined with various commercial xylan and maximum yield was achieved with 0.1∼ 0.5% birchwood xylan. Among various nitrogen sources tested, yeast extract was optimal for the production of xylanase. The xylanase activity was inhibited by $Co^{2+},\; Cu^{2+},\; Fe^{3+},\; Hg^{2+}\;$ and$\;Mn^{2+}$ ions while $Ca^{2+},\; Mg^{2+},\; Ni^{2+},\; Zn^{2+}$ions and DTT stimulated xylanase activity Mercury (II) ion at 5 mM concentration abolished all the xylanase activity. The predominant products of xylan-hydrolysate were xylobiose, xylotriose, and higher xylooligo-saccharides, indicating that the enzyme was an endoxylanase.

• Microbiology and Biotechnology Letters
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• v.34 no.1
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• pp.7-14
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• 2006

Feather, generated in large quantities as a byproduct of commercial poultry processing, is almost pure keratin, which is not easily degradable by common professes. Four strains, SMMJ-2, FL-3, NO-4 and RM-12 were isolated from soil for production of extracellular keratinolytic protease. They were identified as Bacillus sp. based on their morphological and physiological characteristics. They shown high protease activity on 5.0% skim milk agar medium and produced a substrate like mucoid on keratin agar medium. Bacillus sp. SMMJ-2 had a faster production time for producing keratinolytic protease than other strains. This strain did not completely degrade whole chicken feather for five days in basal medium but completely degraded whole chicken feather when supplied with nitrogen source for 40hours in keratinolytic producing medium ($0.7%\;K_{2}HPO_{4},\;0.2%\;KH_{2}PO_{4},\;0.1%$ fructose, 1.2% whole chicken feather, $0.01%\;Na_{2}CO_3$, pH 7.0). When supplied with chicken feather as nitrogen source, keratinolytic protease activity was 89 units/ml/min. When soybean meal was used as nitrogen source, the keratinolytic protease production reached a maximum of 106 units/ml/min after 48 hours under $30^{\circ}C$, 180 agitation. To isolate the keratinolytic protease, the culture filtrate was precipitated with $(NH_4)_{2}SO_4$ and acetone. The recovery rate of keratinolytic protease was about 96% after treatment with 50% acetone. The enzyme was stable in the range of $30{\sim}50^{\circ}C$ and pH $6.0{\sim}12.0$.

• Korean Journal of Ecology and Environment
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• v.46 no.3
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• pp.409-418
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• 2013

Global warming due to climate change is a problem facing the entire world. Several factors, such as $CO_2O$ concentration, level of warming, soil temperature, precipitation, water content of soil and denitrification by denitrifying bacteria influence the emission of nitrous oxide ($N_2O$) from soil. In this study, we investigated nitrous oxide emissions from the soil of two wetlands, Jilmoineup in Mt. Odae and Moojechineup in Mt. Jungjok, according to temperature change. Soil collected in Jilmoineup in July showed increasing $N_2O$ emissions as temperature increases, but did not show any significant differences at $10^{\circ}C$ (p<0.05). Soil of $15^{\circ}C$ and $20^{\circ}C$ showed increasing pattern of $N_2O$ emissions until 24 h. After that, however, there was no difference in temperature. Overall, $N_2O$ emissions showed significant differences according to temperature (p<0.05). Soil collected from Moojechineup in July showed increasing $N_2O$ emissions according to temperature increase, but did not show any significant differences at $10^{\circ}C$ (p<0.05) as was the case for Jilmoineup soil. On the other hand, two wetland soils showed a slight increase of $N_2O$ emissions by additional nitrogen supply, but did not show any significant differences in the presence of nitrogen or between nitrogen sources. In conclusion, increasing temperature the wetland soil increased the emission of $N_2O$, which is a known greenhouse gas. In order to more clearly identify $N_2O$ emissions, various subsequent studies such as the influence and correlation of several factors are required.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.460-465
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• 2003

A bacterium, named as strain KL34, producing extracellular pectinase was isolated from soil. The mophological cheracteristics of the isolated bacterium were gram-negative, rod-shaped and endospore unformed. Production of pectinase of strain KL34 was induced only by polygalacturonic acid added to the culture media as a sole carbon source. Pectinase activity of KL34 reached a maximum value in the culture conditions of pH 8.5 at $25^{\circ}C$. Optimal medium for pectinase production was determined to the composition of 2% polygalacturonic acid, 0.25% yeast extract, 0.02% $K_2HPO_4$, 0.02% $CaCl_2$, and 0.05% KCl per liter. The pectinase activity in the culture supernatant reached the highest amount of 54 U/ml after 3 days cultivation in the optimal media.