• Microbiology and Biotechnology Letters
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• v.36 no.2
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• pp.106-114
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• 2008

One bacterium, which showed strong antagonistic activity against H. pylori KCCM 41756, was isolated from kimchi. The strain NO1 was designated as Lactobacillus plantarum NO1 based on Gram staining, biochemical properties, and 16S rRNA gene sequencing. The culture medium $(2{\sim}4{\mu}g/ml)$ of Lb. plantarum NO1 reduced $(40{\sim}60%)$ the urease activity of H. pylori KCCM 41756. Lb. plantarum NO1 inhibited the binding of H. pylori to human gastric cancer cell line, AGS cells, by more than 33%. Lb. plantarum NO1 exhibited high viability (maintained initial viable cell count of $10^9CFU/ml$) in 0.05 M sodium phosphate buffer (pH 3.0) for 2 h, in artificial gastricjuice for 2 h and in 0.3%, 0.5% oxgall for 24 h. Hemolysis phenomena did not observed when Lb. plantarum NO1 was incubated in the blood agar media. We concluded that Lb. plantarum NO1 can be a good candidate as a probiotic, harboring anti-H. pylori activity.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.334-344
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• 2014

The objective of this study was to evaluate the microbiological and physicochemical characteristics, and the antagonistic activity against Helicobacter pylori ATCC 43504, of yogurt fermented with the lactic acid bacteria from Baikkimchi kept under cold storage. The viable cell counts, titratable acidity, viscosity, and total solid content of the yogurt were different according to the bacterial strains used for fermentation. There was no significant change (P>0.05) in the various properties of refrigerated yogurt. Among the tested strains, the strongest resistance against artificial gastric juice and bile salt was found for Lactobacillus brevis BK11 and Lactobacillus paracasei BK57. Due to high lactic acid levels obtained from these two lactic acid bacteria, yogurt may show good anti-Helicobacter effects according to the time-kill assay. In particular, yogurt fermented with L. brevis BK11 significantly reduced the number of H. pylori adhering to gastric epithelial AGS cells and the urease activity of this pathogen (P<0.05).

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.222-229
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• 2009

This study was performed to evaluate effect of different fertilization management practices on soil microbial activities and community structure using soil enzyme activities and PLFA contents in volcanic ash citrus orchard soil. Six experiment plots have differently managed based on the recommended application rate(NPK) of chemical fertilizer and compost for 13 years. Experiment plots were composed of no-fertilization(control), compost only, half amount of NPK with compost (1/2NPK+COM), NPK, NPK with compost(NPK+COM), and 3 times amount of NPK(3NPK). Soil samples collected in early March, May, July, and September 2007. Urease activity was high at NPK+COM in March, May, and September. It was higher in NPK+COM than in NPK. Urease activity decreased according to the order NPK>compost>control in March and May; compost>NPK>control in July and September. Dehydrogenase activity was significantly higher in 1/2NPK+COM($4.3ug\;TPF\;g^{-1}\;24h^{-1}$) than in control($2.4ug\;TPF\;g^{-1}\;24h^{-1}$), May. $\beta$-glucosidase activity was significantly higher in NPK and 1/2NPK+COM than in control, May. In March, Total PLFA contents were higher in NPK+COM($349.2n\;mol\;g^{-1}$) than in 3NPK($228.5n\;mol\;g^{-1}$). And that were higher in 1/2NPK+COM($237.8n\;mol\;g^{-1}$) than in 3NPK($133.1n\;mol\;g^{-1}$), May. Distribution ratio of soil microbial groups by PLFA biomaker were not significantly difference in between seasonal and treatments. Principal component analysis by PLFA profiles showed that microbial community in compost and 3NPK plot were different compared with other treatments in March. But Differences in compost and 3NPK plot were not found in May. Our result showed that the change of microbial community structure affected by fertilization effect and seasonable variation.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.239-247
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• 1983

The effects of some soil conditions on the degradation rate and decomposing pattern of parathion were investigated and the obtained results are summarized as follows: Parathion degraded more rapidly in flooded soils than in non-flooded, in wet soils than in dry soils under non-flooded soils. The degradation rates in paddy and upland soils increased at high temperature than low temperature, higher pesticide concentration than low concentration and higher soil pH level. Parathion in paddy and upland soils was more persistent under soil sterilization than under non-sterilization and degraded rapidly in glucose application. Parathion was more persistent in upland soils than paddy soils under several factors described above. The metabolites identified from the paddy and upland soils by TLC include para-oxon (Rf 0.5), aminoparathion(Rf 0.27), p-nitrophenol(Rf 0.2), p-aminophenol(Rf 0.15). Soil enzyme, acid phosphatase activities decreased more at flooded soils than non-flooded, higher pesticide concentration than low concentration and higher soil pH level and the activity in glucose application was increased. Soil enzymes, urease and dehydrogenase activity decreased more at higher pesticide concentration than low concentration. Comparing with soil enzyme activity in paddy and upland soil, the former was higher than the latter.

• Korean Journal of Microbiology
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• v.51 no.2
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• pp.156-168
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• 2015

The objective of this study is to investigate the anti-Helicobacter pylori and anti-cancer activities of the live cells (LC), cell-free culture supernatants (CFCS), and bacteriocin solution (BS) obtained from Lactobacillus acidophilus BK13 and Lactobacillus paracasei BK57 strains. After incubation for 30 h in MRS broth, the concentration of lactic acid produced by L. paracasei BK57 ($155.9{\pm}10.2mM$) was higher than in MRS broth using L. acidophilus BK13 ($126.8{\pm}7.9mM$). Maximum bacteriocin activity (128 AU/ml) of BK13 strain was observed after 30 h of cultivation at $37^{\circ}C$, however its magnitude was significantly lower than that of BK57 strain (256 AU/ml). The LC of L. acidophilus BK13 and L. paracasei BK57 were able to inhibit the growth of H. pylori ATCC 43504 at different incubation times, depending on the initial inoculum of the LAB. These CFCS and BS obtained from BK13 and BK57 strains dramatically inhibited the growth, adhesive ability, and enzymatic activity of H. pylori. Meanwhile, the anti-cancer effect of the lactic acid from L. acidophilus BK13 and L. paracasei BK57 strains on AGS cells had significant differences with the control group. Therefore, these antagonistic substances-producing strains are potentially useful as new potential antimicrobial agents for the management and prevention of H. pylori infections.

• 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.

• Korean Journal of Organic Agriculture
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• v.30 no.3
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• pp.409-422
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• 2022

Southern blight caused by Sclerotium rolfsii is a serious soilborne disease in economically important crops including pepper. In this study, we conducted a selection of antagonistic bacterial strains and organic materials to biologically control the disease. Out of 39 strains isolated from soils at Jinju in Korea, strain JJ2-01 showed the highest mycelial growth inhibition; garlic oil among various organic materials significantly reduced disease incidence and severity. When a combination of strain JJ2-01 and garlic oil, or each was drenched into the pepper plants, combined treatment and garlic oil significantly suppressed the disease development, however, acid phosphatase activity in garlic oil-treated plants decreased. In the case of combined treatment, the soil activities did not affect by treatment, while soil urease activity was significantly increased by the combined treatment. Therefore, given soil quality and health for sustainable agriculture, the combination of strain JJ2-01 and garlic acid was an effective application for environmental-friendly control of Southern blight in pepper plants.

• Applied Biological Chemistry
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• v.29 no.3
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• pp.294-303
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• 1986

The effects of insecticides on biochemical precesses in soil were studied by determining the effects of the chemical structure of each insecticides on enzyme activities, pesticide residue and total number of bacteria revealed when soil treated with urea was incubated at $28{\pm}1^{\circ}$ for 56 days. The inhibition effects of insectides on enzyme activites in soil decreased in the order: dithiophosphoric acid > thiophosphhoric acid > phosphoric acid > carbamate insecticides for urease and phosphatase, thiophosphoric acid > dithiophosphoric acid > phosphoric acid > carbamate insecticides for L-glutaminase and protease. The inhibition effects of organophophorus insecticides on enzyme activities in soil were maintained longer than those of carbamate insecticides. Carbamate insecticides increased the activities of protease and L-glutaminase at 56 days. When insecticides were treated in soil together with urea, the degradation of insecticides was accelerated. By treatment of insecticides, the total number of bacteria was decreased at the early stage of treatment but thereafter increased according to phosphoric acid and carbamate insecticides.

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.84-89
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• 2005

Mongolian dandelion (Taraxacum mongolicum H.) extracted with solvents having different polarities were prepared to investigate protection activity of gastric mucosa. Ethanol extracts were successively reextracted with methylene chloride, and n-butanol. Concentrations of total flavonoids and luteolin in n-butanol extracts were 27.75 and 1.14%, respectively, much higher than those of other solvent extracts. Results of anti-microbial acitivity test against Helicobacter pylori and urease inhibition test revealed n-butanol extract exerted higher inhibition (13.16%) than other solvent extracts. Based on 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay, n-butanol extract showed the highest efficiency of free radical-scavenger activity among the extracts ($SC_{50}\;47{\mu}g/mL$). Erythrocytic photohemolysis tests, for the protection of cell membrane showed that half-life of human erythrocytes was increased by the addition of n-butanol extract $({\tau}_{50}=172min;C=5.0{\mu}g/mL)$. These results indicate n-butanol extract of Mongolian dandelion may be useful as a adjuvant for gastric diseases.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.74-79
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• 1991

In order to use of new organic matter source, soil samples collected from paddy, upland and orchard treated with kraft and paper board mill sludge were analysed comparing with non-treated soil in view of some soil properties, soil microorganisms and soil enzyme activities. Also, the value of fertilizer was estimated with kraft and paper board mill sludge. 1. Paper mill sludge showed more than 55% of organic matter content, and higher total nitrogen and phosphorus, and CEC. 2. Soils treated with kraft sludge were higher contents than non-treated 2.5-3 for organic matter, 1.5-2 for total-nitrogen, 2 for $NO_3$-N, 1.5 for phosphorus and 1.4 times for CEC. Also, 12-1.9 for bacteria and 3 times for fungi, and 1.4-1.5 of cellulase, 1.5-1.8 of phosphatase and 1.5-1.8 times of urease activities. 3. Organic matter contents, number of fungi, and activities of cellulase and phosphatase in soil treated with paper board sludge were 1.4-22, 2.4, 1.5-1.6 and 1.3-1.4 times higher than non-treated soil, respectively. 4. Paper mill sludge was evaluated as a good organic matter source to increase of soil organic matter, CEC, inorganic components, soil microbes and enzyme activities.