• Applied Biological Chemistry
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• v.31 no.1
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• pp.79-85
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• 1988

The effects of herbicides on biochemical processes in soil environment were studied by examining the effects of the chemical structure of each herbicides on soil enzyme activities and pesticides residue revealed when soil treated with urea was incubated at $28{\pm}1^{\circ}C$ for 56 days. The inhibition effects of herbicides on soil enzyme activites in soil decreased in the order of urea group>dinoseb>propanil>diphenyl eter group>acid amide group for urease, and dinoseb>urea group>diphenyl ether group>acid amide group for L-glutaminase and protease, dinoseb>diphenyl ether group>urea group>acid amide group for phosphatase. Herbicides inhibited the activities of soil enzyme in the early stage of treatment but increased the activities of urease, L-glutaminase and protease in the late stage. When herbicides were treated in soil together with urea the degradation of insecticides was accelerated.

• Restorative Dentistry and Endodontics
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• v.23 no.1
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• pp.43-53
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• 1998

Dental caries is induced by organic acids produced by oral bacteria. In order to prevent dental caries, therefore, it is essential to maintain neutral pH in the oral cavity. Urea plays a major role in oral pH homeostasis. Urea is hydrolyzed by bacterial ureases to ammonia, causing a pH elevation. Streptococcus salivarius has been shown to be a major contribution to oral ureolysis. Synthesis of urease by S. salivarius appears to be constituitive, but can be greatly enhanced by low pH. It is, therefore, conceivable that ureolytic activity of S. salivarius from a carious lesion is greater than that of the bacterium from a healthy tooth. In the present study, urease activity of S. salivarius isolates from dental plaque of carious lesions was compared with that of the isolates from plaques of the teeth and the dorsum of the tongue; 45 S. salivarius strains were isofated from carious lesions(>C2) of 21 individuals with dental caries and 30 strains from 10 individuals without dental caries. The results were as follows: 1. All the 21 individuals with dental caries harbored ureolytic S. salivarius whereas 3 of 13 individuals without dental caries harbored non-ureolytic strains of S. salivarius. 2. All the 45 S. saliuarius isolates from carious lesions showed urease activity. In contrast, of 30 isolates from individuals without dental caries, 17 isolates(56.7%) did not demonstrate urease activity, or if any, very little(<5${\mu}mol$/min/mg). 3. Urease activity of the isolates from carious lesions was greater than that of the isolates from individuals without dental caries : the urease activity ranged from 42 to $381{\mu}mol$/min/mg and from 0 to $208{\mu}mol$/min/mg, respectively. 4. At acid pH(5.5), the isolates which showed intermediate urease activity at pH 7.0 demonstrated even higher activity whereas the isolate with no or lower urease activity did not show any significant difference in their activity. However, the isolates with the greatest urease activity from both individuals with and without dental caries, exhibited a rather much lower urease activity at pH 5.5. The overall results suggest that isolates may have their own urease activity but the isolates exposed to chronic acidic environment of the carious lesion might elevate urease activity of S. salivarius, which in turn, might influence on survival of S. salivarius itself and other bacteria, establishing a new oral bacterial ecosystem.

• 한국생물공학회:학술대회논문집
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• 2003.04a
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• pp.727-728
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• 2003

• Microbiology and Biotechnology Letters
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• v.28 no.3
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• pp.161-166
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• 2000

Antifungal Activity and Identification of an Actinomycetes Strain Isolated from Mummified Peaches. Lirn, Tae Heon*, Jung Mok Lee, Tae Hyun Chang, and Byeongjin Chal. *Research Institute of Plant Nutrient, Oaeyu Co, Inc. Kyongsan 712-820, Korea, 1 Department of Agricultural Bi%g'f Chungbul< NatJ"onal Univershy, Cheongju 367-763, Korea - An actinomycetes strain which produced chitinase, urease, and antifungal substances to MoniliniaJhtcticola was isolated from peaches mununified by Moniliniafructicola. The strain TH-04 was identified as Streptomyces sp. based on cultural and lTIOIphological characteristics, cell wall diaminopimelic acid, and sugar patterns ofwhole~cell extracts. Streptomyces sp. TH~04 showed antifungal activity to several fungi including Moniliniafructicola, Colletotrichum gloeosporioides, Magnaponhe grisea, Rhizoctonia solani, Phytophthora capsici, Altemaria kikuchiana, Fusarium solani, and Fusarium O),ysporum. The optimum cultural conditions for the production of antifungal substances were $20^{\circ}C$pH 7, and 7 days.

• Korean Journal of Microbiology
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• v.35 no.2
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• pp.128-132
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• 1999

The effects of diet on the composition of fecal microflora in mouse and the aclivilies of several enzymes in the leces were investigated. Vegetarian dietary groups were found to contain about ten lines higher numbers of Locmbocillus and B$&bacterizml than animal dietary groups. An~rnal dietmy groups were found to contain about 5 tolo times higher numbers of anaerobic Closhidia and Bocieriocles than the vegeterian detary groups. Fccal microbial $\beta$-glucosidase, $\beta$-glucm'onidase, ii-yptophanase and orease activilies in ihe animal dietary groups were shown lo be 30 to 50% hgher than those in h e vegetarian detary groups.

• Korean Journal of Food Science and Technology
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• v.30 no.5
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• pp.1012-1017
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• 1998

This study was performed to investigate the change of lipoxygenases and urease activities, trypsin inhibitor, tannin and phytic acid contents during heat treatment of Jinpum soybean. The lipoxygenase-1 and urease possessed their activities after heating at $60^{\circ}C$ for 100 min, but their activities disappeared rapidly at $80^{\circ}C$ and $100^{\circ}C$ for 20 and 10 min. There were no lipoxygenase-2 and -3 activities in Jinpum soybean with and without heating. Trypsin inhibitor was lost 91.9%, 78,1% and 58.6% of the activity after heat treatment at $100^{\circ}C$ for 50 min, at $80^{\circ}C$ for 100 min and at $60^{\circ}C$ for 100 min, respectively. The tannin content was increased by heat treatment. The content of and phytic acid was increase after heating at $60^{\circ}C$ for 100 min, unchanged at $80^{\circ}C$ for 100 min and decreased at $100^{\circ}C$ for 100 min.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.1
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• pp.61-71
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• 1988

This study was conducted to find out the effect of herbicides on soil micro-organism and soil enzyme in loam soil, and on pathogenic microorganism in continuous pepper cropping soil. The result was summarized as follows: When herbicides were treated, the number of soil microorganism generally decreased at the early stage of incubation, and gradually increased at 30 days incubation. The number of fungi was significantly decreased seven times comparison with control plot. The number of actinomycetes was increased at 20 days incubation and that of pytium was increased for all days incubation in Linuron treatment plot. Although the activity of soil enzyme tended to decrease when herbicides were treated, the activities of urease and phosphatase were higher than that of control plot at the early stage of incubation in MO, Linuron and Simetryne treatment plot. In Simetryne treatment plot, the activity of protease was increased at the early stage, and suddenly decreased after 30 days incubation. There was no significant effect of herbicides on the activities of ${\beta}$-glucosidase and polygalacturonase. The activity of cellulase was inhibited at the early stage of incubation, but that of cellulase was higher than that of control plot after 20 days incubation. High significance was showed the correlation coefficient between soil microorganisms except fungi and soil respiration as herbicides were treated, and the total microorganism and soil respiration in Linuron plot. when Dicamba and Simetryne were treated, the correlation coefficient between the total microorganism and the activities of protease and urease were considerably significant.

• Korean Journal of Microbiology
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• v.41 no.2
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• pp.152-156
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• 2005

In the present study, lactic acid bacterium that has antibacterial activity against Helicobacter pylori was isolated from feces of newborn baby. The selection was based on the ability to inhibit the growth of H. pylori and to withstand harsh environmental conditions such as acidic pH and high bile concentration. By biochemical test and 16S rDNA sequencing, selected strain was turned out to be an Pediococcus acidilactici, therefore designated to P. acidilactici GMB7330. In order to investigate the inhibitory effects of P. acidilactici GMB7330 on the growth of H. pylori, we have tested in vitro studies such as cell viability and urease test. These results showed that antibacterial activity of P. acidilactici GMB7330 significantly decreased the viable cell count and urease activity of H. pylori. Antibacterial activity of P. acidilactici GMB7330 against H. pylori remained after pH adjustment to neutral, and the concentration of lactate produced from P. acidilactici GMB7330 was not enough to inhibit H. pylori. On the basis of the analysis by transmission electron microscope, it demonstrated that addition of P. acidilactici GMB7330 destroyed the cell structure of H. pylori. These results strongly suggested that P. acidilactici GMB7330 produce antibacterial substances to be able to inhibit the growth of H. pylori other than lactic acid.

• Applied Biological Chemistry
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• v.36 no.6
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• pp.510-516
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• 1993

The degradation and leaching pattern of benzoylurea insecticide teflubenzuron and flucycloxuron in soil environment and their effect on urease activity were investigated. The half-life of teflubenzuron was 39.1 days and 20.9 days in Chilgok and Ansim soil of nonsterilized condition, respectively, and that of flucycloxuron was 102.3 days and 50.1 days. Teflubenzuron and flucycloxuron were degraded more rapidly in Ansim soil with rich organic matter than Chilgok soil, and were degraded very slowly under sterilized condition. Their degradation seemed to be mainly mediated by microorganisms in soil. Teflubenzuron was degraded 63.2 days and 29.2 days faster than flucycloxuron under nonsterilized condition of Chilgok and Ansim soil. The inhibition of urease by the pesticides in two kinds of soil was strongly affected $(37.6{\sim}42.4%)$ in the early stage of their treatment but hardly affected or increased a little after 120 days. The teflubenzuron and flucycloxuron remained in the upper 5 cm of the soil column after elution with 1,000 ml of water, and they were not detected in leachate.

• Journal of the Korea Organic Resources Recycling Association
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• v.31 no.3
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• pp.83-91
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• 2023

This study investigate growth responses of Chinese cabbage and nitrogen use efficiency (NUE) to application of fermented organic fertilizer produced from domestic organic resources for developing alternative materials instead of imported castor oil meal. Two types of fermented fertilizers (Fermented Organic Fertilizer A (OFA) and Fermented Organic Fertilizer B (OFB)) were produced by mixing distillers dried grains 30%, sesame cake 30%, rice bran 20% and fish meal 20% under different fermentation conditions. Treatment consisted of OFA is fermented for 21 days on plastic greenhouse, OFB is fermented for 5 days on 40℃, and MOF (Mixed Organic Fertilizer) is a fertilizer made with castor bean as the main ingredient. OFA, OFB and MOF were applied at the rate of 320 kg N/ha. Chinese cabbages were cultivated from Aug. to Nov. in 2022. Growth and yield of Chinese cabbage were no significant differences among all treatments except control (non-fertilized, NF). However, NUE of Chinese cabbage was higher the fermented fertilizer treatment (OFB: 81.4%, OFA: 79.1%) than the MOF (65.3%). It was observed that urease activity in the fermented fertilizer treatment was significantly higher than the MOF. This result confirmed that fermented fertilizers have similar effect on growth and yield with the MOF and could improve the NUE of crop.