• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.2
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• pp.41-48
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• 2011

In this study, the soil remediation by landfarming was carried out using microbial activators. Feasibility studies and reduction capacity of TPH(Total Petroleum Hydrocarbons) were investigated in order to find out how fast and eco-friendly the contaminated soil can be recovered. The lab-test confirmed not only the performance and degradation efficiency of microbial activators but also the effect of TPH reduction in the contaminated soil. The optimum growth conditions for indigenous microorganisms were identified using microbial activators. Based on the results of TPH removal, although there had been a little of difference in between natural decomposition and microbial activators until 20 days, the sample groups of microbial activators were higher than the control ones after 20 days. Microbial activators were applied to the field experiments on landfarming. Based on the results of removal rate in each floor of soil, it was found that the removal rates were 85.8 % in the upper, 84.4 % in the middle, and 66.10 % in the bottom. Considering that the reduction rate of TPH for the control group averaged 71.1%, the microbial activators might not be fully transferred into the bottom, which resulted from the piles of soil. As the piles have already reached 1 m in the field experiments, the low piles of soil under 0.6 m may enhance the treatment efficiency of TPH.

• 한국생물공학회:학술대회논문집
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• 2005.04a
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• pp.324-324
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• 2005

• Korean Journal of Weed Science
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• v.17 no.1
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• pp.112-123
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• 1997

Chemical pesticides have been re used for a long time to protect crops from diseases, insects, and weeds ; ample and secure supply of foods in present days would not be possible without them. However, concerns on the risk of using chemical pesticides rising steadily in recent years forced discard many of them and seek an alternate, environment-friendly control strategies. Microbial pesticide is regarded as one of the most promising methods because if properly developed, it will be effective, cheap, and environment-safe. Currently, about 180 microbial pesticides are under development throughout the world and at least 20 of them including B.t. and antibiotics are registered in Korea. This paper discusses some of the successful examples, intriguing problems, and future prospects of microbial pesticides.

• KSBB Journal
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• v.28 no.5
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• pp.275-281
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• 2013

Soil microbial community analysis of farmland soil sprayed with lye in order to use fertilizer in Nigeria was performed. As a control, two kinds of soils not sprayed with lye, located in Eungo and Lagos with general practice in agriculture was selected. Soil sprayed with lye was pH 8.25 through alkalization reaction, while the other soil samples were pH 6.22 and 5.94. Substrate utilization and species diversity index of soil sprayed with lye were low than that of the other soils with the analysis of Biolog ecoplate. As a result of principal component analysis, the relationship between three samples was low. Microbial community analysis was performed by DGGE and most of them were soil uncultured bacterium. Especially, Uncultured Acidobacteria and Uncultured Methylocystis sp., which had been isolated from the rhizosphere of soybean grown in that site were discovered in the soil sprayed with lye.

• Journal of Korean Society on Water Environment
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• v.31 no.4
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• pp.399-406
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• 2015

A sequencing batch reactor was operated under different pH conditions to see the influence of free ammonia (FA) and free nitrous acid (FNA) to microbial community on ammonium partial nitrification. Long-term influences of FA and FNA were evaluated by polymerase chain reaction-denaturing gradient gel electrophoresis and fluorescence in situ hybridization. Nitrite accumulation was successfully achieved at pH 8.2 and 6.3. The shifts in the microbial community were observed when influent ammonia concentration increased to 1 g $NH_4$-N/L at pH 8.2, and then when pH was dropped to 6.3. Both Nitrosomonas and Nitrosospira were selected during the startup of the reactor, and eventually became dominant members as ammonia-oxidizing bacteria. The results of molecular microbiological analysis strongly suggested that the composition of microbial community was changed according to the method used to control nitrite-oxidizing bacteria.

• Journal of Microbiology
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• v.44 no.3
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• pp.354-359
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• 2006

This study examined the capacity of immobilized bacteria to degrade petroleum hydrocarbons. A mixture of hydrocarbon-degrading bacterial strains was immobilized in alginate and incubated in crude oil-contaminated artificial seawater (ASW). Analysis of hydrocarbon residues following a 30-day incubation period demonstrated that the biodegradation capacity of the microorganisms was not compromised by the immobilization. Removal of n-alkanes was similar in immobilized cells and control cells. To test reusability, the immobilized bacteria were incubated for sequential increments of 30 days. No decline in biodegradation capacity of the immobilized consortium of bacterial cells was noted over its repeated use. We conclude that immobilized hydrocarbon-degrading bacteria represent a promising application in the bioremediation of hydrocarbon-contaminated areas.

• Preventive Nutrition and Food Science
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• v.6 no.4
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• pp.240-243
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• 2001

Fresh pasta was packaged in a modified atmosphere of 22% $CO_2$/78% $N_2$ and compared with a control air package for its quality changes during storage at 8$^{\circ}C$. The modified atmosphere packaging suppressed the microbial growth of total aerobic bacteria and yeasts/molds with a concomitant reduction in the rates of physical and chemical quality changes, and thus successfully extended the shelf life of fresh packs from 20 days of air packs to 40 days based on microbial criterion of 10$^{6}$ cfu/g. The shelf life extension was greater when the initial microbial quality of the product was better.

• Preventive Nutrition and Food Science
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• v.9 no.3
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• pp.218-221
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• 2004

Irradiated red pepper powder (IRPP) was tested for its ability to retard fermentation and to maintain a high quality of Kimchi by the reduction of the initial microbial load. Kimchi containing IRPP at the doses of 0, 5, 10, 15, or 20 kGy was prepared. Quality indices for Kimchi in this study were pH, titratable acidity, reducing sugar content, total microbial count, lactic acid bacterial load, and sensory evaluation. Based on the pH and titratable acidity, the Kimchi with IRPP showed a retarded fermentation until 15 days. The number of the total aerobes and lactic acid bacteria of the Kimchi with IRPP were lower by about 1 log CFU/mL compared to control at day 0, however, the counts increased to 8.5 log CFU/mL after 10 days, which was similar to the control group. Kimchi that was fermented with 5 kGy IRPP was better than control and other treatments in odor and color, whereas the control scored highest in taste. Addition of IRPP showed a limited retardation of Kimchi fermentation without other quality deterioration.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.460-467
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• 2013

This study was conducted to reduce the using amount of chemical fungicides for the control of red-pepper Phytophthora blight. Effect of combination application of two microbial fungicides and two chemical fungicides for the control of red-pepper Phytophthora blight was examined in vitro, in greenhouse and under field conditions. Each microbial fungicides and chemical fungicides was two-fold diluted and mixed-soil drenched. In the greenhouse pot assay, the mixed application of B. pumilus QST2808 and a mixture of dimethomorph + ethaboxam (De) among four mixed applications of two microbial fungicides (B. pumilus QST2808, P. polymyxa AC-1) and two chemical fungicides showed the highest control effect against Phytophthora blight. Also, control effect of mixed application of B. pumilus QST2808 and De was similar to that of single application of De (dimethomorph + ethaboxam) or Mo (mancozeb + oxadixyl). In the field test, when the microbial fungicides (B. pumilus QST2808, P. polymyxa AC-1) and the chemical fungicide(De) for the control of Phytophthora blight of red pepper were mixed-soil drenched four times at 7~10 day-intervals, the control values were in the range of 78.8% to 82.0%. On the other hand when each of the two chemical fungicides (De, Mo) were soil drenched four times at 7~10 day-intervals, the control value were 65.7% to 85.8%. Consequently, the mixed application of the microbial fungicides and chemical fungicides could be recommended as a control method for reducing the using amount of chemical fungicides.

• Asian-Australasian Journal of Animal Sciences
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• v.12 no.2
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• pp.197-202
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• 1999

Three barrows weighing 45.0 kg, fitted with simple T-cannulas in both the duodenum and terminal ileum, were assigned to diets in a $3{\times}3$ Latin Square design experiment to determine the effect of two calcium levels (0.8% vs 0.4%) on phytase activity and nutrient balance in growing pigs. The control diet contained 0.8% calcium, with no added inorganic phosphorus (0.45% total phosphorus) and no added phytase. The two additional experimental diets contained microbial phytase (750 phytase units/kg) and supplied either 0.8% or 0.4% calcium. With added microbial phytase, ileal and total tract digestibility of rotal phosphorus were improved by 20.9 and 13.8 percentage units, respectively (p=0.01). The apparent duodenal and ileal digestibility of phytate phosphorus were increased by 51.8 and 49.7 percentage units (p=0.01). Lowering dietary calcium in the presence of microbial phytase increased the digestibility of phytate phosphorus by an additional 10.9 (p=0.001) and 5.7 percentage units for duodenal and ileal digestibility, respectively. Supplementation with microbial phytase significantly reduced fecal excretion of nitrogen and phosphorus and increased the percentage of these nutrients retained by the pig. Lowering dietary calcium further increased the percentage of dietary phosphorus retained. Overall, reducing dietary calcium appeared to increase the effectiveness of added microbial phytase in degrading phytate phosphorus. As a result, care should be taken to avoid high levels of dietary calcium when supplementing swine diets with microbial phytase.