• Journal of Plant Biotechnology
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• v.30 no.3
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• pp.269-273
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• 2003

In order to develop an efficient micropropagation protocal for Eucalyptus pellita, on in vitro culture system has been was established by inducing axillary buds from greenhouse stock materials. Among 6different media tested, DKW medium was the best ot induce bast induce both shoot proliferation and growth. Average number of proliferated shoots of 403per explant was obtained at the concentration of 0.1mg/LBA. Most of the stem materials excreted phenolic compounds at the proximal part of the explant and caused darking of the media. Therefore, it was necessary to transfer frequently to a fresh medium and/or to add activated charcoal at the concentration of 0.02％(w/v). Generally on vitro roots were formed easily on 1/2DKW medium with NAA treatment. All the explants rooted at the medium containing 0.2mg/L NAA and displayed vigorous root growth in vitro culture conditions. After transferred to an artificial soil mixture (peatmoss: vermiculrite: perlite, 1:1:1, v/v/v) in the greenhouse, most rooted plantlets survived well without any morphological abnormalities. The results show that the species can be micropropagated effectively by the application of axillary bud culture system.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.316-318
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• 2004

In recent years, plastic waste has been recognized as a worldwide environmental issue. To solve the disposal problem of the plastic waste, alternative treatment such as the use of biodegradable plastic(polybutylene succinate: PBS) is indeed highly in demand due to its merit of PBS buried in soil decomposed into carbon dioxide and water. In the present study, for the production of further functional PBS with TiO$_2$ as photocatalyst, which shows the decomposition of detrimental organic compound and pollutant under ultraviolet irradiation, we attempted to prepare photocatalytic TiO$_2$ coatings on PBS substrate by HVOF and plasma spraying techniques under various conditions using three kinds of agglomerated powders (P200: 200nm, P30: 30nm, P7: 7nm). The microstructures of coatings were characterized with SEM and XRD analysis, and the photocatalytic efficiency of coatings was evaluated through the photo degradation of gaseous acetaldehyde. Therefore, such functional TiO$_2$-Plastic composite material is expected to considerably contribute to the reduction of aggravated environmental problem.

• Journal of Microbiology and Biotechnology
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• v.5 no.4
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• pp.206-212
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• 1995

A strain BL-29, which produces a extracellular lytic enzyme on E. coli was isolated from the soil. The strain was identified as belonging to the genus Bacillus sp. The lytic enzyme was purified to homogeneity by ion exchange chromatography and gel filtration. Specific activity of the purified enzyme was 28, 850 U/mg protein and yield of the enzyme was 5$%$. The purified enzyme showed a single band on SDS-PAGE and its molecular weight was estimated to be 31, 000 by SDS-polyacrylamide gel electrophoresis and gel filtration column chromatography. The optimum temperature and pH were $55^{\circ}C$ and pH 10.0, respectively. The enzyme was stable at $45^{\circ}C$ but enzyme activity was reduced by up to 50$%$ when the temperature was raised to $55^{\circ}C$ for 15 min. Stable range of pH was from 5.0 to 11.0. but Enzyme activity was inhibited by lead-acetate, mercuric chloride, ethylene glycol-bis-[$\beta$-aminoethyl ether]-N, N, $N^1, $N^1$-tetraacetic acid (EGTA), and ethylenediamine tetraacetic acid (EDTA), but not affected considerably by treatment with other chemical reagents.

• Journal of Microbiology and Biotechnology
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• v.15 no.1
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• pp.221-225
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• 2005

A Staphylococcus sp. EY-3 with the capability of decolorizing Congo Red was isolated from soil at an effluent treatment plant of a textile and dyeing industry. This strain was able to almost completely decolorize a high concentration of Congo Red in 48 h under aerobic conditions. Optimal color removal (more than 96%) was achieved at 30- 40oC, and no noticeable effects of different pH values (5.5- 8.0) on decolorization were observed. This strain also exhibited a remarkable decolorization capability against azo dyes under aerobic conditions, even at a high concentration (dyes 1 g/l) of dye. The metabolic product of Congo Red degradation by this strain was identified by gas chromatography with mass selective detection (GC/MSD) to be an amine derivative benzidine.

• Microbiology and Biotechnology Letters
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• v.24 no.1
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• pp.82-86
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• 1996

Three thousand microbial strains collected from different sources were screened for herbicidal activity. A strain of ME-9189 showed herbicidal activity against Digitaria sanguinalis and Portulaca oleracea was isolated from a mountainy soil. Based on taxonomic studies, the strain was identified as Streptomyces tubercidicus. The active compound of ME-9189 was purified from the culture broth by charcoal, silica gel, sephadex LH-20 column chromatography and crystalization, consecutively. The ME-9189 compound was identified as tubercidin by spectroscopic methods of UV, $^{1}H$ and $^{13}C$-NMR, and EIMS. In the bioassay, growth of radish shoot and root was inhibited by 50% with tubercidin treatment of 10 ppm, showing 2 times higher activity than that of herbicidin A and similar to that of toyocamycin.

• Korean Journal of Microbiology
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• v.38 no.4
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• pp.235-240
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• 2002

Protease producing bacterium, PB16 was isolated from food processing wastewater sludge and paddy field soil samples and selected by the clear zone and enzyme activity test. The isolate was gram negative, rod type and its protease productivity was 6.49 U/ml. As a result of API20NE kit test and 16S rDNA sequencying, the isolated PB16 was identified as Aeromonas hydrophila (99%). The growth rate ($h^{-1}$) was 0.21 in synthetic waste water only and 0.26 in synthetic waste water containing vitamin and mineral using a bioscreen C. Synthetic wastewater removal rate was 59 and 87%, respectively after 1 and 3 day reaction (intial CODcr was 2,472 mg/l).

• Korean Journal of Environmental Agriculture
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• v.25 no.3
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• pp.262-267
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• 2006

Increased application of glyphosate (Gly) in glyphosate-resistant (GR) soybean cropping systems may affect rhizospheric microorganisms including IAA-producing rhizobacteria (IPR) and their effect on the growth of soybean. This field experiment was conducted to assess IPR populations in the rhizosphere of GR soybean ('Roundup-Ready' DeKalb DKB38-52) treated with glyphosate and foliar amendment treatments such as $PT21^{(R)}$ (urea solution with N 21 %) and $Grozyme^{(R)}$ (Biostimulant: mixtures of micro nutrients and enzymes). Effects of herbicide, sampling date, and their interaction on total bacterial numbers were significant (P < 0.001, 0.001, 0.013, respectively). Total bacteria (TB) numbers were increased with glyphosate treatment at 20 d after application and highest TB populations were associated with $Grozyme^{(R)}$ application, possibly due to the additional substrate from this product. The IPR of the soybean rhizosphere was significantly affected by herbicide, sampling date, and the herbicide*foliar amendment interaction. The ratios of numbers of IPR to TB ranged from 0.79 to 0.99 across the sampling dates irrespective of treatments. IPR numbers were slightly hindered by glyphosate application regardless of foliar amendment.

• Journal of the Korea Organic Resources Recycling Association
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• v.9 no.1
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• pp.119-126
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• 2001

This research was carried out to evaluate the effect of recycled wastewater and surfactant above CMC(critical micelle concentration) on the removal rate of PAHs in bench-scale slurry bioreactor. Kinetic parameters based on zero order and first order kinetic models were estimated. The first order model was able to describe the removal of phenanthrene and pyrene with high correlation coefficients. Addition of recycled wastewater could enhance the removal rates of phenanthrene and pyrene. Addition of surfactant above CMC could enhance desorption rate and removal rate of phenanthrene and pyrene.

• Microbiology and Biotechnology Letters
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• v.22 no.6
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• pp.665-671
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• 1994

For the production of pyrogallot from gallic acid, about 100 strains of bacteria capable of assimilating gallic acid as a sole carbon and energy source were isolated from the soil. JH- 004 strain showing the highest activity of gallate decarboxy#lase was selected from them and identi- fied as Erwinia sp. The optimal conditions for the production of pyrogallol from gallic acid were examined. The resting cells of JH-004 cultured in a complex medium containing 0.2%(w/v) gallic acid were prepared after the treatment of the pellet with a freezing and thawing, and used as a enzyme source. The reaction mixtures for the maximal production of pyrogallol were shown to be 6 g/l of resting cells and 15 g/l of gallic acid in 25 mM potassium phosphate buffer. The optimal pH for the reaction was 5.0 and the optimal temperature was 35$\circ$C . Additionally, Triton X-100(0.01%, w/v) was found to be most effective for the production of pyrogallol. Under the above conditions, 10.27 g/l of pyrogallol was produced from 15 g/l of gallic acid after incubation of 35 hrs. This amount of pyrogallol corresponds to a 92.37% yields, based on gallic acid.

• Journal of Microbiology and Biotechnology
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• v.14 no.4
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• pp.859-862
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• 2004

An isolate of Pseudomonas putida has been found to aggressively colonize root tips and induce plant resistance to Fusarium wilt. However, P. putida mutants lacking Fe-superoxide dismutase (SOD) or both FeSOD and MnSOD activities are less competitive in root tip colonization. In the current study, the growth of an FeSOD mutant was found to be more sensitive than that of the wild-type or a MnSOD mutant to oxidative stress imposed by paraquat treatment and culturing with the soil fungus Talaromyces flavus, which generates reactive oxygen species. Also, the loss of culturability with an aging stationary-phase culture was greater for a double SOD mutant than an FeSOD mutant, while no reduction in culturability was observed with the wild-type and a MnSOD mutant under the same protracted stationary-phase conditions. Accordingly, it was concluded that FeSOD activity is the major form of SOD in P. putida and plays an essential role in survival under stress conditions when increased oxidative stress is encountered.