• Journal of Microbiology and Biotechnology
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• v.20 no.11
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• pp.1592-1596
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• 2010

To verify the dominance of microorganisms in wastewater biological treatment, PCR-DGGE (denaturing gradient gel electrophoresis) was performed as a supplementary support method for screening of the dominant microorganisms from activated sludge. Results suggest that the dominant microorganisms in activated sludge are primarily responsible for strengthening its effectiveness as a biological treatment system, followed by the non-main dominant microorganisms, whereas the non-dominant microorganisms showed no effects. The degree of microbial abundance present on the profile of PCR-DGGE was in line with the treatment efficiency of augmented activated sludge with isolated cultures, suggesting that PCR-DGGE can be used as an effective supplementary method for verifying culturable dominant microorganisms in activated sludge of coking wastewater.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.23 no.2
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• pp.84-94
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• 2013

Objectives: The objective of this study is to identify the composition of dominant microorganisms in waste handling industries. Methods: We collected airborne bacteria and fungi by agar plate impaction method in recyclable waste sorting industry, food recycling industry, landfill and incineration. Isolated dominant microorganisms were identified by VITEK system or morphological analysis. Results: We isolated totally 330 microorganisms in the process and outdoor. Bacillus was the most dominant genus in the all industries, and Sphingomonas, Acinetobacter, Staphylococcus, and Proteus was dominant bacterial genus. The dominant genus of fungi was Penicillium, Aspergillus, and Cladosporium in each industries. Enterobacter, Pseudomonas, Klebsiella, and Proteus was identified as the dominant gram negative bacteria. The ratio of bacteria being biosafety levels(class 1 or 2) was 58.3~77.8%. Conclusions: This study has investigated the dominant microorganisms in the waste handling industries. The genus of dominant microorganisms was similar among the industries but the composition was different. We used biosafety levels as qualitative method, but further studies are needed about specific process of qualitative evaluation methods.

• Microbiology and Biotechnology Letters
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• v.27 no.2
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• pp.113-117
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• 1999

As a basic study for quality improvement of Korean soybean paste and soybean sauce, we investigated on microflora of soybean paste and soybean sauce fermentation. Major Microorganisms were isolated from the sample pastes and sauces, and identified systematically. Selected Microorganisms were identified by MIS whole cell fatty acid analysis by gas chromatography. Identification results showed that Bacillus licheniformis, bacillus pumilis and Bacillus subtilis were dominant in soybean paste and Staphylococcus vitulus, Bacillus subtilis, Bacillus pumilus, and Lactobacillus fermentum were dominant in soybean sauce. It seemed that these Microorganisms played an important role in soybean paste and soybean sauce fermentation and could be used for the further studies such as protease and amylase activities.

• Microbiology and Biotechnology Letters
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• v.39 no.4
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• pp.374-381
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• 2011

The beneficial effects of Eisenia fetida on soil properties have been attributed to their interaction with soil microorganisms. The bacterial diversity of the intestinal tract of E. fetida was investigated by culture-dependent and culture-independent methods including denaturing gradient gel electrophoresis (DGGE) and pyrosequencing analyses. In a pure culture, Lysinibacillus fusiformis (51%), Bacillus cereus (30%), Enterobacter aerogenes (21%), and L. sphaericus (15%) were identified as the dominant microorganisms. In the DGGE analyses, B. cereus (15.1%), Enterobacter sp. (13.6%), an uncultured bacterium (13.1%), and B. stearothermophilus (7.8%) were identified as the dominant microorganisms. In the pyrosequencing analyses, Microbacterium soli (26%), B. cereus (10%), M. esteraromaticum (6%), and Frigoribacterium sp. (6%) were identified as the dominant microorganisms. The other strains identified were Aeromonas sp., Pseudomonas sp., Borrelia sp., Cellulosimicrobium sp., Klebsiella sp., and Leifsonia sp. The results illustrate that culture independent methods are better able to detect unculturable microorganisms and a wider range of species, as opposed to isolation by culture dependent methods.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.4
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• pp.416-424
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• 2014

Objectives: The objective of this study is to analyze the predominant microorganisms in the industry treating MWFs(Metal working fluids). Methods: The bacteria and fungi were collected by agar plate impaction and bulk MWFs in storage tank at 54 sites in 9 shops in South Korea. The dominant bacteria and fungi isolated from agar media were identified by fatty acid analysis and morphological analysis, respectively. Results: Totally 111 dominant bacteria were identified in the process, outdoor, and bulk MWFs. The predominant bacterial genus was Micrococcus and Bacillus in the process and outdoor, Pseudomonas in bulk MWF. Among the identified 119 strains of fungi, Cladosporium and Penicillium genus were dominated. The ratios of bacteria designated biosafety level 2 and 1 were 30% and 21%, respectively. Conclusions: This study has investigated the dominant microorganisms in soluble MWF using industry. And it was useful that the qualitative evaluation method along with quantitative analysis for better understanding of the biological factors in the work environment.

• Asian Journal of Turfgrass Science
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• v.10 no.3
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• pp.247-262
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• 1996

In this study, the distribution of dictyostelid cellular slime molds was investigated from F, H and $A_1$ horizon of pinus, oak forests in Mt. Puk'an, Mt. Nam and Mt. Kwanak. The relationship of cellular slime molds with other soil microorganisms and abiotic factors were analyzed. The six species were isolated as follows: Polysphondlium pallidurn, Dictyostelium purpureum, D. mucoroides, D. crassicaule, D. capitatum, D. implicatum. The dominant species in pinus forests was P. pallidum, and in oak forests it was D. macro ides. In Mt. Nam, D. mucoroides and P. pallidum were isolated at only oak forest. The Correlations of slime mold abundance with bacteria were significant. Even though positive correlations of cellular slime molds with actinomycetes or fungi were not significant, correlations between soil microorganisms were analyzed. Correlation coefficients were high in Mt. Kwanak(r=0.5921) and Mt. Nam(r=0.7243) at significant level P<0.01. There were significant correlations between total slime molds and abiotic factors. It supports that cellular slime molds are limited by foods in nature. In low level of pH, water content and organic matter, that community diversity is more affected by bacteria whose organic degradation capacity is regulated by interactions of soil microorgaisms. Key words: Cellular slime molds, Soil microorganisms, Correlations, Abiotic factors.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.195-201
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• 2011

Today, the weather is changing continually, due to the progress of global warming. As the weather changes, the habitats of different organisms will change as well. It cannot be predicted whether or not the weather will change with each passing day. In particular, the biological distribution of the areas climate change affects constitutes a major factor in determining the natural state of indigenous plants; additionally, plants are constantly exposed to rhizobacteria, which are bound to be sensitive to these changes. Interest has grown in the relationship between plants and rhizopheric microorganisms. As a result of this interest we elected to research and experiment further. We researched the dominant changes that occur between plants and rhizospheric organisms due to global warming. First, we used temperature as a variable. We employed four different temperatures and four different sites: room temperature ($27^{\circ}C$), $+2^{\circ}C$, $+4^{\circ}C$, and $+6^{\circ}C$. The four different sites we used were populated by the following strains: Pinus densiflora, Pinus koraiensis, Quercus acutissima. We counted colonies of these plants and divided them. Then, using 16S rRNA analysis we identified the microorganisms. In conclusion, we identified the following genera, which were as follows: 24 strains of Bacillus, 6 Paenibacillus strains, 1 Pseudomonas strains. Among these genera, the dominant strains in Pinus densiflora was discovered in the same genus. Additionally, those of Pinus koraiensis and Quercus acutissima changed in both genus and strains which changed into the Bacillus genus from the Paenibacillus genus at $33^{\circ}C$.

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.885-892
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• 2011

The bacterial communities in the intestinal tracts of earthworm were investigated by culture-dependent and -independent approaches. In total, 72 and 55 pure cultures were isolated from the intestinal tracts of earthworms under aerobic and anaerobic conditions, respectively. Aerobic bacteria were classified as Aeromonas (40%), Bacillus (37%), Photobacterium (10%), Pseudomonas (7%), and Shewanella (6%). Anaerobic bacteria were classified as Aeromonas (52%), Bacillus (27%), Shewanella (12%), Paenibacillus (5%), Clostridium (2%), and Cellulosimicrobium (2%). The dominant microorganisms were Aeromonas and Bacillus species under both aerobic and anaerobic conditions. In all, 39 DNA fragments were identified by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis. Aeromonas sp. was the dominant microorganism in feeds, intestinal tracts, and casts of earthworms. The DGGE band intensity of Aeromonas from feeds, intestinal tracts, and casts of earthworms was 12.8%, 14.7%, and 15.1%, respectively. The other strains identified were Bacillus, Clostridium, Enterobacter, Photobacterium, Pseudomonas, Shewanella, Streptomyces, uncultured Chloroflexi bacterium, and uncultured bacterium. These results suggest that PCR-DGGE analysis was more efficient than the culturedependent approach for the investigation of bacterial diversity and the identification of unculturable microorganisms.

• Korean Journal of Agricultural Science
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• v.48 no.3
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• pp.493-503
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• 2021

Tricholoma matsutake (Pinus mushroom, PM) is one of the most valued ectomycorrhizal fungi in Asia because it is an expensive forest product with a unique flavor and taste. Therefore, many studies have tried to successfully cultivate Tricholoma matsutake artificially in Korea and other countries. However, its physiological and ecological characteristics are still unknown. Thus, we need to understand the diversity and clusters of microorganisms related to Tricholoma matsutake and to identify their core microorganisms related to their growth and production. In this study, we obtained an average of 11,661 fragments from three pine mushrooms with metagenome (an assemblage of genes of all microorganisms in the natural world) analysis from a pine forest located in Pohang, Gyeongsang-Bukdo. Of these, the valid reads were on average 5,073 per sample available for analysis, and the average length of a read was 456 bp. There were an average of 33.3 phyla in the metagenome analysis. Firmicutes phylum made up on an average 46% of the phyla and was dominant among the phyla. The next dominant phylum was Proteobacteria at 27% followed by Bacteroidetes at 17%, Actinobacteria at 5% and Verrucomicrobia at 2%. The Proteobacteria phylum consisted of the γ-proteobacteria class at 54% followed by β-proteobacteria at 37%, α-proteobacteria at 6%, δ-proteobacteria at 2% and ζ-proteobacteria at 0%. The metagenome consisted of the Ruminococcaceae family at 17% followed by Pseudomonadaceae at 13%, Burkholderiaceae at 7%, Bacteroidaceae at 7%, Lachnospiraceae at 7% and Clostridiaceae at 6%.

• Journal of Food Hygiene and Safety
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• v.31 no.3
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• pp.201-209
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• 2016

Many atmospheric pollutants including chemical agents, house dust, and microorganisms cause building-related illnesses through respiration in humans. This study was conducted to analyze the profiles of microbial pollutants in air purifiers used in home, office and playschool. Dominant eleven species of microorganisms were isolated and identified in environmental air and air purifiers. Among them, Staphylococcus sp., Micrococcus sp. and Bacillus sp. are the most dominant species. By phylogenetic analysis of the 16S rRNA gene, the dominant bacteria were identified as Staphylococcus epidermidis, Micrococcus luteus and Bacillus epidermidis, respectively. It has been known that these bacterial species are closely related with food spoilage and human infectious disease. Thus, these results indicate that microbial pathogens related with human illnesses through respiration will be contaminated in air purifiers and also need to develop a method to control those of pathogens for human health.