• Journal of Microbiology and Biotechnology
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• v.17 no.4
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• pp.560-570
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• 2007

The effective and accurate assessment of the total microbial community diversity is one of the primary challenges in modem microbial ecology, especially for the detection and characterization of unculturable populations and populations with a low abundance. Accordingly, this study was undertaken to investigate the diversity of the microbial community during the biodegradation of cis- and trans-dichloroethenes in soil and wastewater enrichment cultures. Community profiling using PCR targeting the l6S rRNA gene and denaturing gradient gel electrophoresis (PCR-DGGE) revealed an alteration in the bacterial community profiles with time. Exposure to cis- and trans-dichloroethenes led to the disappearance of certain genospecies that were initially observed in the untreated samples. A cluster analysis of the bacterial DGGE community profiles at various sampling times during the degradation process indicated that the community profile became stable after day 10 of the enrichment. DNA sequencing and phylogenetic analysis of selected DGGE bands revealed that the genera Acinetobacter, Pseudomonas, Bacillus, Comamonas, and Arthrobacter, plus several other important uncultured bacterial phylotypes, dominated the enrichment cultures. Thus, the identified dominant phylotypes may play an important role in the degradation of cis- and trans-dichloroethenes.

• Microbiology and Biotechnology Letters
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• v.19 no.6
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• pp.631-636
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• 1991

The bacteria which can biodegrade aromatic compounds were screened from soil and wastewater. The isolated Pseudomonas sp. HC107 had high removal rate of COD and phenol. And also this strain grew on m-cresol, salicylate, toluene, 2, 4-D and benzene. When the strain culture (2 ml/day) was treated on continuous reactor at mixed wastewater from chemical, pharmaceutical and dye industry, the treatment rate of COD, BOD and phenol was to be about 92.5%, 95.3% and 93.5%, respectively.

• Korean Journal of Food Science and Technology
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• v.49 no.2
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• pp.141-145
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• 2017

In this study, we evaluated the alcohol degradation ability of fig enzyme in the production of cheese using Lactobacillus kitasatonis, Lactobacillus amylophillus, and Leuconostoc mesenteroides sub. The strains were highly resistant to ethanol, acid, and bile acid. When 10% of fig enzyme was added, the alcohol dehydrogenase and aldehyde dehydrogenase activities in each strain were approximately 170, 270, and 190% higher, respectively, than in samples without fig enzyme. The addition of 10% of fig enzyme to produce cheese with the L. amylophillus strain showed an approximately 250% increase in alcohol dehydrogenase and aldehyde dehydrogenase degradation. In conclusion, when fig enzyme was added to produce cheese using L. amylophillus, high alcohol degradation ability was observed. The applicability of fig enzyme addition was confirmed for the production of functional food.

• Journal of Microbiology and Biotechnology
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• v.31 no.5
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• pp.740-746
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• 2021

Efficient cellulolytic enzyme production is important for the development of lignocellulose-degrading enzyme mixtures. However, purification of cellulases from their native hosts is time- and labor-consuming. In this study, a constitutive expression system was developed in Penicillium oxalicum for the secreted production of proteins. Using a constitutive polyubiquitin gene promoter and cultivating with glucose as the sole carbon source, nine cellulolytic enzymes of different origins with relatively high purity were produced within 48 h. When supplemented to a commercial cellulase preparation, cellobiohydrolase I from P. funiculosum and cellobiohydrolase II from Talaromyces verruculosus showed remarkable enhancing effects on the hydrolysis of steam-exploded corn stover. Additionally, a synergistic effect was observed for these two cellobiohydrolases during the hydrolysis. Taken together, the constitutive expression system provides a convenient tool for the production of cellulolytic enzymes, which is expected to be useful in the development of highly efficient lignocellulose-degrading enzyme mixtures.

• 한국생물공학회:학술대회논문집
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• 2000.04a
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• pp.370-373
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• 2000

In this work, an extractive membrane bioreactor containing coulture broth of Burkholderia cepacia G4 PR1 constitutively expressing the TCE-degrading enzyme, tolune-ortho-monooxygenase(TOM), was used for the degradation of TCE. The membrane bioreactor operates by seperating the TCE-containing waste gas from the aerated biomedium, by which the air-stripping of TCE without degradation was overcome that could occur in conventional aerobic biological treatments of TCE-contaminated waste gases. This was achieved by a silicone rubber membrane which was coiled around a perspex draft tube. TCE from the gas phase diffuses across the silicone rubber membrane into microbial culture broth that was continuously fed from a separate aerobic CSTR. Therefore, TCE degradation occured without the TCE being directly exposed to the aerating gas stream. Of the TCE supplied to the membrane bioreactor, 72.6% was biodegraded during the operation of this system. To construct a mathematical model for this system, parameters describing microbial growth kinetics on TCE were determined using a CSTR bioreactor. Else parameters used for numerical simulation were determined from either indepedent experiments or values reported in the literature. The model was compared with the experimental data, and there was a good agreement between the predicted and the measured TCE concentrations in the system. To achieve a higher treatment efficiency, various operating conditions were simulated as well.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.141.3-142
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• 2000

No Abstract, See Full Text

• Proceedings of the Microbiological Society of Korea Conference
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• 2006.05a
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• pp.124-126
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• 2006

• Journal of Microbiology
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• v.43 no.1
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• pp.49-53
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• 2005

Putative genes for a two-component signal transduction system (akbS and akbT) were detected near the alkylbenzene-degrading operon of Rhodococcus sp. DK17. Sequence analysis indicates that AkbS possesses potential ATP-binding and histidine autophosphorylation sites in the N- and C-terminal regions, respectively, and that AkbT has a typical response regulator domain. Mutant analysis combined with RT-PCR experiments further shows that AkbS is required to induce the expression of o-xylene dioxygenase in DK17.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.04a
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• pp.103-106
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• 2003

This study was conducted to evaluate in-situ bioremediation ability of Bioil-D, microbial material for oil degradation, at a gas station that had been treated by SVE system. TPH concentrations and total contaminated soil volume were rapidly decreased after Bioil-D treatment. The performance of Bioil-D was also estimated based on the observation of microbial population at the soil samples and $CO_2$ concentration produced at the extraction wells. The field study showed a successful work of Bioil-D.

• Environmental Engineering Research
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• v.20 no.2
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• pp.149-154
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• 2015

In recent years, immobilization agents were introduced into organic contaminated soil remediation and more and more materials were screened and used as the immobilizing carrier. However, effect of the decomposition of the immobilizing carrier on the bioremediation was rarely concerned. Therefore, the decomposition experiment of immobilizing carrier -corncob was carried out in the lab with the efficient degradation fungi - Mucor mucedo (MU) existing, and polycyclic aromatic hydrocarbons (PAHs) residues E4/E6 of the dissolved organic matter and microbial diversity during the decomposition process were studied. The results showed that: a) during the decomposition, the degradation of pyrene (Pyr) was mainly in the first 28 d in which the content of extractable Pyr decreased rapidly and the highest decrease was in the treatment with only MU added. b) Anslysis of E4/E6 changes showed that rich microorganisms could promote aromatization and condensation of humus. c) From the diversity index analysis it can also be seen that there is no significant difference in effects of PAHs on the uniformity of microorganisms. These results will not only be useful to have a better understanding of the bioavailability of contaminants adsorbed to biodegradable carriers in PAHs contaminated soil remediation, but also be helpful to perfect the principle of immobilized microbial technique.