• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.39-42
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• 2004

Landfarming and a microbial agent, Bioil-D, were used to treat diesel-contaminated soil. The microbial agent was applied to the contaminated soil in a concentration of 5$\times$10$^2$ cfu/soil(g) and the total amount of microbial agent, 210$\ell$, was sprinkled on the soil four times for 24 days during 50 day-remediation period. The remediation goal, lower than 800mg/kg of TPH, was achieved from 5, 707 mg/kg of TPH within 50 days. The total number and activity of indigenous microorganisms were increased by 100 times after the microbial agent, Bioil-D, was applied to the contaminated soil.

• Korean Journal of Microbiology
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• v.23 no.2
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• pp.147-156
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• 1985

Seasonal and vertical variations of abiontic soil carboxymethylcellulase (CMCase) activities were assessed every other month for a year in two contrasting forest soils and evaluated the relationships between soil CMCase activity and environmental parameters. In climax deciduous soil, variations in CMCase activities caused by differences in sampling time were greater than those caused by differences in soil depth. On the other hand, counter phenomenon was obserned in coniferous soil at the stage of development. Correlation analyses showed that soil CMCase activities were significantly (p>0.01) correlated with microbial respiration rates ($O_2$ uptake) and all of the microbial population sizes. From these results, it is suggested that determination of abiontic soil CMCase activity is an useful additional index for evaluating the overall microbial growth and activity in soils.

• Journal of Life Science
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• v.12 no.5
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• pp.515-522
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• 2002

Effect of the microbial product, which consisted of Bacillus coagulans DL-1 and rice bran, on the microorganisms in soil and growth of cabbage and tomato was investigated. Bacillus congulans DL-1 was isolated form the soil and identified in this study. Total number of microorganisms in the soil treated with the microbial product was higher than the untreated soil. The growth of cabbage and tomato on the soil treated with microbial product was faster than that on the untreated soil. The treatment of microbial product in the soil resulted in the increase of useful microorganisms, which seemed to enhance the growth of cabbage and tomato. It seemed that microbial product can increase the number of certain microorganisms and change the ratio of different species of microorganisms.

• Korean Journal of Microbiology
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• v.35 no.1
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• pp.78-81
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• 1999

The change of soil microbial populations was studied at the burnt areas of Mt. Jirisan in Hddong-Gun, Kyungsangnam-Do, where the fire had occurred on Oct. 21 in 1997. On the first day of the fireextinguished, the microbial density (CFUIg dry soil) was investigated at the surface, 5 cm, 10 cm, 20cm, and 30 cm depth of soils. Bacteria at the surface and 5cm depth of burnt sites were estimatedwith the low density level of $10^2$ CFW/g soil comparing to the $10^6$ CFUIg soil of the neighboring unburntsites. Actinomycetes of burnt sites were completely disappeared at the surface, and were estimatedwith the low density level of $10^3$ CFUig soil at thc 5 cm depth comparing to the 10"CFUigsoil at the depth of unburnt sites. Fungi wcrc not isolated at the surface and 5 cm depth at all.However, the rarest lire was not found to decrease the microbial populalions at the lower depths than10 cm. In addilion, the recovery or soil microbial populations following the fire was bimonthly investigatedat the surrace and 5 cm depth. Most of microbial densities at the burnt sites were greatlyincreased two months after the fire, being enough to he compared with the neighboring unburnt sites.However, actinomycetes only at the surface of burnt sites still were estimated the low density level of$10^4$ CFUig soil 4 months after the fire comparing to the $10^6$CFIg soil of unburnt sites.TEX>CFIg soil of unburnt sites.

• Korean Journal of Organic Agriculture
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• v.9 no.3
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• pp.103-117
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• 2001

This study was inducted to investigate the effects of microbial fertilizers on the fields of young radish(Raphanus sativus L.), chemical components of plant and soil, and the microbial floras. Six microbial fertilizers, MPK+Husk+Palma, Husk+Palma, MPK+Compost, Compost, BIO Livestock Clean System(BLCS) cattle dropping, and Tomi were used. The yields of young radish were increased in six microbial fertilizer treatments. The fresh matter weight, the number of leaves, and the dry matter weight of young radish in BLCS cattle dropping treatment, the leaf length in MPK+Husk+Palma treatment, the sugar content in Husk+Palma treatment, arid the leaf width in Tomi treatment showed the highest amount, respectively. The effects of microbial fertilizers on chemical characteristics of young radish and soil were examined. Phosphoric acid amount of young radish in Tomi treatment was much higher than other treatments. Potassium amount of young radish showed high significance in all microbial fertilizer treatments compared with control, and shoved the highest in Compost treatment . Two components, phosphoric acid find potassium, in soil inoculated by microbial fertilizers showed significant. Phosphoric acid in the Tomi treatment and Potassium in Husk+Palma treatment were increased. The microorganic populations in soil inoculated with microbial fertilizers were examined. While the number of Bacillus in ceil was increased in MPK+Husk+Palma treatment, the numbers of total bacteria, actinomycetes, and fungi were increased in Tomi treatment.

• Korean Journal of Environmental Agriculture
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• v.40 no.3
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• pp.194-202
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• 2021

BACKGROUND: Towards achievement of sustainable agriculture, using microbial inoculants may present promising alternatives without adverse environmental effects; however, there are challenging issues that should be addressed in terms of effectiveness and ecology. Viability and stability of the bacterial inoculants would be one of the major issues in effectiveness of microbial pesticide uses, and the changes within the indigenous microbial communities by the inoculants would be an important factor influencing soil ecology. Here we investigated the stability of the introduced bacterial strains in the soils planted with barley and its effect on the diversity shifts of the rhizosphere soil bacteria. METHODS AND RESULTS: Two different types of bacterial strains of Bacillus thuringiensis and Shewanella oneidensis MR-1 were inoculated to the soils planted with barley. To monitor the stability of the inoculated bacterial strains, genes specific to the strains (XRE and mtrA) were quantified by qPCR. In addition, bacterial community analyses were performed using v3-v4 regions of 16S rRNA gene sequences from the barley rhizosphere soils, which were analyzed using Illumina MiSeq system and Mothur. Alpha- and beta-diversity analyses indicated that the inoculated rhizosphere soils were grouped apart from the uninoculated soil, and plant growth also may have affected the soil bacterial diversity. CONCLUSION: Regardless of the survival of the introduced non-native microbes, non-indigenous bacteria may influence the soil microbial community and diversity.

• Korean Journal of Environmental Agriculture
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• v.20 no.5
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• pp.325-329
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• 2001

Soil enzyme and microbial activities are affected by fertilizer and compost applications and can be used as sensitive indicators of ecological stability. Microbial population and soil enzymes viz., dehydrogenase, urease, acid phosphatase and aryl-sulphatase were determined in the long-term fertilizer and compost applied paddy soil. Soil samples were collected from the four treatments (control, compost, NPK and compost+NPK). Long-term NPK+compost application significantly increased activities of urease, dehydrogenase and acid phosphatase than all other treatments. The compost application enhanced activities of urease, dehydrogenase and acid phosphatase than the NPK application. However, arylsulfatase activity was not significantly different between compost and fertilizer application. The highest microbial population was recorded in the NPK+compost treatment. The compost application also resulted in higher microbial population than the NPK application. The above results indicate that ecological stability could be maintained by application of compost alone or with NPK.

• Journal of Soil and Groundwater Environment
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• v.26 no.4
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• pp.20-26
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• 2021

In this work, an indigenous microbial consortium was obtained by selectively cultivating microbes using a long-aged petroleum-contaminated soil (Kuwait) containing recalcitrant petroleum hydrocarbons. The obtained microbial consortium was able to grow on and degrade the remaining petroleum hydrocarbons which could not have been utilized by the indigenous microbes in the original Kuwait soil. The following microbial community analysis using 16S rRNA gene sequencing suggested that the enhanced degradation of the remaining recalcitrant petroleum hydrocarbons by the novel microbial consortium may have been attributed to the selected bacterial populations belonging to Bacillus, Burkholderia, Sphingobacterium, Lachnospiraceae, Prevotella, Haemophilus, Pseudomonas, and Neisseria.

• Journal of Ginseng Research
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• v.40 no.1
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• pp.28-37
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• 2016

Background: Panax ginseng cannot be cultivated on the same land consecutively for an extended period, and the underlying mechanism regarding microorganisms is still being explored. Methods: Polymerase chain reaction and denaturing gradient gel electrophoresis (PCR-DGGE) and BIO-LOG methods were used to evaluate the microbial genetic and functional diversity associated with the P. ginseng rhizosphere soil in various cultivation ages and modes. Results: The analysis of microbial diversity using PCR-DGGE showed that microbial communities were significantly variable in composition, of which six bacterial phyla and seven fungal classes were detected in P. ginseng soil. Among them, Proteobacteria and Hypocreales dominated. Fusarium oxysporum, a soilborne pathogen, was found in all P. ginseng soil samples except R0. The results from functional diversity suggested that the microbial metabolic diversity of fallow soil abandoned in 2003was the maximum and transplanted soil was higher than direct-seeding soil and the forest soil uncultivated P. ginseng, whereas the increase in cultivation ages in the same mode led to decreases in microbial diversity in P. ginseng soil. Carbohydrates, amino acids, and polymers were the main carbon sources utilized. Furthermore, the microbial diversity index and multivariate comparisons indicated that the augmentation of P. ginseng cultivation ages resulted in decreased bacterial diversity and increased fungal diversity, whereas microbial diversity was improved strikingly in transplanted soil and fallow soil abandoned for at least one decade. Conclusion: The key factors for discontinuous P. ginseng cultivation were the lack of balance in rhizosphere microbial communities and the outbreak of soilborne diseases caused by the accumulation of its root exudates.

• The Korean Journal of Ecology
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• v.18 no.4
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• pp.503-512
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• 1995

The present paper describes partial results of the study on the activities of microbes in the soil of Quercus mongolica forest from July, 1994 to April, 1995. To determine the relationship between structure and function of soil microbial ecosystem, the author investigated the seasonal change of physical environmental factors, microbial population and soil enzyme activities. The changes of pH was not significant and the temperature of surface soil was 2℃ higher than lower soil through out the year. Moisture contents (％) of soil samples ranged from 7.64％ to 42.11％. However, soils of site 3 at Mt. Komdan in which vegetation is successional have higher moisture content than the others. The bacterial population increased in summer, but continuously decreased in autumn and winter, and then reincreased again in spring. Bacterial population of surface soil was higher than those of 30 cm depth all the year round. Dehydrogenase activity (DHA) was about two-fold higher throughout in surface soil compared to those of lower soil. And the correlation coefficient between DHA and bacterial population size was 0,713, It was suggested that DHA could be used as a primary index of soil microbial population and activity in soil ecosystem.