• Korean Journal of Soil Science and Fertilizer
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• v.42 no.6
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• pp.500-512
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• 2009

This study was carried out to evaluate the effect of temperature on soil microbial biomass, enzyme activities, and PLFA content in the volcanic(VAS) and the non-volcanic ash soil(NVAS). The soils were treated with organic materials such as organic fertilizer pelleted(OFPL), organic fertilizer powdered(OFPD), pig manure compost(PMC), and food waste compost(FWC). Two grams of organic materials were well mixed with 30g of dried volcanic and non-volcanic ash soil(< 2 mm) with 50% of soil moisture content. And the soils were incubated at 10, 20, $30^{\circ}C$ in incubator. Soils were analysed on the incubation times as followed; soil pH, total nitrogen, organic matter(at 75, 150, 270 days), microbial biomass C and PLFA (at 75, 270 days), microbial biomass N and soil enzyme(at 150, 270 days). pH values of soils treated with PMC and FWC had no changes on soil type, and incubation temperature. However, the pH was increased with temperature in the soils treated with OFPL. The changes in NVAS was higher than in VAS. Soil microbial biomass C content were high in the condition of high temperature and organic fertilizers treatment in VAS. But the contents were gradually decreased with incubation period in both NVAS and VAS. Soil microbial biomass N was high in NVAS treated with organic fertilizers and in VBS treated with PMC and FWC. PLFA content was higher in NVBS than in VBS at 75 days but showed high in VBS at 270 days. Urease activity of NVBS treated with OFPL showed $10^{\circ}C$ (75.0)> $20^{\circ}C$ (16.3)>$30^{\circ}C$ ($4.6ug\;NH{_4-}N\;g^{-1}\;2h^{-1}$) at 150 days. It were decreased gradually high temperature and time passes. And it showed high at $10^{\circ}C$ in VBS. Glucosidase activity was higher in NVBS than in VBS. Correlation coefficient of between soil microbial biomass C and microbial activity indicators showed that PLFA was high significantly at $r^2=0.91$ in NVBS and ${\beta}-glucosidase$ was $r^2=0.83$ in VBS. Soil microbial activities showed differences in the relative sensitivities of soil type and soil temperature.

• KSBB Journal
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• v.14 no.3
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• pp.322-327
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• 1999

The cholesterol oxidase(EC.1.1.3.6) produced from Streptomyces sp. No.4 which isolated from soil was purified and investigated for the enzymatic properties. The enzyme was purified specifically by cholesterol affinity column chromatography with a yield of 28.3%. The purified enzyme showed a single polypeptide on SDS-PAGE and the molecular weight was estimated to be 60,000 daltons. The enzyme activity was strongly inhibited by metal ions such as $HgCl_2$ and $CuSO_4$. Dithiothreitol and mercaptoethanol inhibited the enzyme activity at concentration of 1mM. The Michaelis constant(Km) for cholesterol was found to be 1.38mM by Lineweaver-Burk plot analysis. Amino acid analysis showed that the enzyme protein was composed of 416 amino acid residues including 52moles of glycine and 19moles of tryptophane.

• Journal of Microbiology and Biotechnology
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• v.2 no.1
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• pp.14-20
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• 1992

Some microorganisms isolated from soil, including some bacteria and fungi, were found to secrete an extracellular soymilk-clotting enzyme. Among them, an isolated fungus showed the highest soymilk-clotting activity and the strain was assigned to genus Penicillium based on its cultural and morphological characteristics, and designated as Penicillium sp. L-151K. Soymilk-clotting enzymes A and B produced by Penicillium sp. L-151K were purified by ammonium sulfate precipitation and chromatographies on Sephadex G-25, CM-Sephadex, Sephadex G-100 and phenyl-Toyopearl gel. The two purified enzymes A and B were found to be homogeneous by polyacrylamide gel electrophoresis at pH 9.5. The molecular weights of enzyme A and B were 24, 000 and 40, 000, respectively, by gel filtration on Sephadex G-100. Enzymes A and B coagulated soymilk optimally at $60^\circ{C}$ and were stable up to $50^\circ{C}$. Both enzymes were most active at pH 5.8 for soymilk coagulation, and were stable with approximately 80% of original activity from pH 3.0 to 5.0. Each enzyme was an acidic protease with an optimum pH of 3.0 for casein digestion. The soymilk-clotting efficiency of these enzymes was improved with $CaCl_2\;or\;MgCl_2$ when making soymilk-curd.

• Journal of Microbiology and Biotechnology
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• v.7 no.1
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• pp.37-42
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• 1997

A bacterial strain L1 producing a thermostable esterase was isolated from soil taken near a hot spring and identified as Bacillus stearothermophilus by its microbiological properties. The isolated thermostable esterase was purified by ammonium sulfate fractionation, ion .exchange and hydrophobic interaction chromatographies. The molecular weight of the purified enzyme was estimated to be 50,000 by SDS-PAGE. Its optimum temperature and pH for hydrolytic activity against PNP caprylate were $85^{\circ}C$ and 9.0, respectively. The purified enzyme was stable up to $70^{\circ}C$ and at a broad pH range of 4.0-11.5 in the presence of bovine serum albumin. The enzyme was inhibited by phenylmethylsulfonyl fluoride and diethyl p-nitrophenyl phosphate, indicating the enzyme is a serine esterase. The enzyme obeyed Michaelis-Menten kinetics in the hydrolysis of PNPEs and had maximum activity for PNP caproate ($C_6$) among PNPEs ($C_2-C_12$) tested.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.614-620
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• 2016

Mine soils are usually unfavorable for plant growth due to their acidic condition and low contents of organic matter and nutrients. To investigate the effect of organic material and lime on nitrogen processes in an acidic metal mine soil, we conducted an incubation experiment with treating livestock manure compost, dolomite, and oyster shell and measured soil pH, dehydrogenase activity, and concentration of soil inorganic N ($NH_4{^+}$ and $NO_3{^-}$). Compost increased not only soil inorganic N concentration, but also soil pH from 4.4 to 4.8 and dehydrogenase activity from 2.4 to $3.9{\mu}g\;TPF\;g^{-1}day^{-1}$. Applying lime with compost significantly (P<0.05) increased soil pH (5.9-6.4) and dehydrogenase activity ($4.3-7.0{\mu}g\;TPF\;g^{-1}day^{-1}$) compared with applying only compost. Here, the variation in dehydrogenase activity was significantly (P<0.05) correlated with that in soil pH. Soil inorganic N decreased with time by 14 days after treatment (DAT) due to N immobilization, but increased with time after 14 DAT. At 28 DAT, soil inorganic N was significantly (P<0.05) higher in the lime treatments than the only compost treatment. Especially the enhanced dehydrogenase activity in the lime treatments would increase soil inorganic N due to the favored mineralization of organic matter. Although compost and lime increased soil microbial biomass and enzyme activity, ammonia oxidation still proceeded slowly. We concluded that compost and lime in acidic mine soils could increase soil microbial activity and inorganic N concentration, but considerable ammonium could remain for a relatively long time.

• Journal of Ecology and Environment
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• v.33 no.3
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• pp.261-270
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• 2010

Increasing atmospheric $CO_2$ affects the soil carbon cycle by influencing microbial activity and the carbon pool. In this study, the effects of elevated $CO_2$ on extracellular enzyme activities (EEA; ${\beta}$-glucosidase, N-acetylglucosaminidase, aminopeptidase) in salt marsh sediment vegetated with Suaeda japonica were assessed under ambient atmospheric $CO_2$ concentration (380 ppm) or elevated $CO_2$ concentration (760 ppm) conditions. Additionally, the community structure of sulfate-reducing bacteria (SRB) was analyzed via terminal restriction fragments length polymorphism (T-RFLP). Sediment with S. japonica samples were collected from the Hwangsando intertidal flat in May 2005, and placed in small pots (diameter 6 cm, height 10 cm). The pots were incubated for 60 days in a growth chamber under two different $CO_2$ concentration conditions. Sediment samples for all measurements were subdivided into two parts: surface (0-2 cm) and rhizome (4-6 cm) soils. No significant differences were detected in EEA with different $CO_2$ treatments in the surface and rhizome soils. However, the ratio of ${\beta}$-glucosidase activity to N-acetylglucosaminidase activity in rhizome soil was significantly lower (P < 0.01) at 760 ppm $CO_2$ than at 380 ppm $CO_2$, thereby suggesting that the contribution of fungi to the decomposition of soil organic matter might in some cases prove larger than that of bacteria. Community structures of SRB were separated according to different $CO_2$ treatments, suggesting that elevated $CO_2$ may affect the carbon and sulfur cycle in salt marshes.

• Korean Journal of Microbiology
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• v.24 no.3
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• pp.295-301
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• 1986

The bacteria, which were capable of producing ${\beta}-1$, 3-glucanase inducibly by utilizing cell wall of Aspergillus fumigatus as a sole carbon source, were isolated from soil in the campus of Kyungpook National University. Among them, the strain which produced the enzyme excellently was selected and identified to be Pseudomonas stutzeri KF 13 by morphological, cultural and physiological examination. The optimal conditions for the enzyme production from Pseudomonas stutzeri KF 13 were investigated. the enzyme production was reached maximum state shen the broth cultured for 72hr at $30^{\circ}C$. And the enzyme showed the highest activity in the medium containing 3.5% cell wall as an inducer, 15% yeast autolysate as a nitrogen source and 0.05% $MnSO_4$ at pH 7.5.

• Microbiology and Biotechnology Letters
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• v.19 no.2
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• pp.116-121
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• 1991

A bacterial strain KN, which highly produced a protease, was isolated from several soil samples and identified to to belong to the genus Bacillus. We selected mutant strain Bacillus sp. KN103N, which was hyperproducer of protease and was resistant to D-cyclowerine, from the strain KN by several steps of mutagenesis. Neutral protease productivity of mutant strain KN103N was about 55 times as much as that of the original strain KN. The optimum pH and temperature for the enzyme activity were 7.0 and 50$^{\circ}C$, respectively and the enzyme was relatively stable at pH6.0~8.0 and below 40$^{\circ}C$. The enzyme was inactivated by EDTA, but not by DFP. These results indicate that the enzyme from Bacillus sp. KN103N was a neutral (metallo-) protease.

• Microbiology and Biotechnology Letters
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• v.25 no.2
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• pp.151-158
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• 1997

For the production of potent chitinolytic enzyme from bacteria, screening was carried out. Of 100 samples from soil, fresh water and sea water collected from the Kyung-gi area, 7 strains of chitinolytic bacteria were isolated. Among them, Aeromonas hydrophila 5-3K showed the highest chitinolytic activity. Culture conditions of Aeromonas hydrophila for the production of chitinolytic enzyme were inverstigated and lytic enzyme was fractionated by the use of ammonium sulfate and Sephadex G-100. Maximum production of chitinolytic enzyme was obtained at pH 7.0 and 30$\circ$C with chitin concentration between 0.2% and 1.0%. Conditions for the enzyme production were optimized including fermentor cultivation. The chitinolytic system of Aeromonas hydrophila 5-3K was composed of two enzymes, chitinase and chitobiase.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.445-451
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• 1996

The strain YCH-37, which produces yeast cell wall lytlc enzyme, was isolated from soil. From the microscopic observation, morphological and cultural characteristics, this strain was identified to fungus, Dicyma sp. So, we named this strain as Dicyma sp. YCH-37. The lytic enzyme effectively lysed Salmonella typhimurium among intact living bacteria and Torulopsis, Hansenula, Zygosaccharomyces among intact living yeast, as well as autoclaved yeast strains. The yeast cell wall lytic enzyme was succesively purified to 204 folds with 13% yields through yeast glucan affinity adsorption and DEAE-cellulose column chromatography. The enzyme was identified to monomeric protein with molecular weight of 25,000 daltons from the results of SDS-PAGE and gel filtration. The optimum pH and temperature for the yeast lytic activity were 8.0 and 50$\circ$C, respectively. The enzyme was stable up to 40$\circ$C, and between pH 4.0-pH 10.0.