• Korean Journal of Microbiology
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• v.33 no.4
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• pp.267-273
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• 1997

Various physico-chemical and microbiological parameters of a composting system were compared with respect to their potential use for the monitoring and evaluation of composting processes for cattle manure. The temperature changed within a range of $30-65^{\circ}C$ during the whole composting process, and the period of active composting (>$40^{\circ}C$) persisted for 16 days. The concentrations of total carbon, total nitrogen, and organic matter decreased by 15% during active composting, but significant changes in C/N ratio were not observed. The decrease of temperature in the latter period of active composting caused a decrease of $NH_4^+-N$ and an increase of $NO_3^--N$ in the composting pile. When temperature exceeded $50^{\circ}C$, the population of thermophiles was higher than that of mesophiles by more than 1 or 2 orders of magnitude. Correlation analyses showed that amylase activity correlated positively with the population of mesophiles and reducing sugar content, but negatively with the population of thermophiles. Amylase activity was higher at the beginning of active composting, whereas cellulase, xylanase and ligninase activities which showed close relationship with each other, increased continually during active cornposting, suggesting the distinction of temporal niches between amylose-degrading and lignocellulose-degrading bacteria in the same habitat.

• Journal of the Korean Wood Science and Technology
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• v.25 no.2
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• pp.1-20
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• 1997

목재를 분해시키는 담자균류들은 목재 및 목질복합체에 쉽사리 침투하여 복잡한 리그노셀룰로오스 복합체를 분해시킨다. 이러한 분해에는 많은 효소시스템들이 복합적으로 작용하면서 상호 협동하는 것으로 보고되고 있다. 지금까지 일려진 효소들은 통상 3개의 그룹으로 나눌 수 있는데 그 하나는 목재성분을 직접적으로 공격하는 효소균들, 예를 들면 cellulase complex, laccase(LAC), lignin peroxidase(LIP), horse-radish peroxidase(HRP), manganese-independent peroxidase(MIP) 및 protocatechuate 3,4-dioxygenase(PCD) 등이 있고, 두번째 그룹으로서 manganese-dependent peroxidase(MnP), aryl alcohol oxidase(AAO) 및 glyoxal oxidase(GLO) 등인데, 이들 효소들은 목질을 직접적으로 공격하지 않고 제1그룹의 효소들과 협동하여 작용하는 것으로 알려지고 있다. 제3그룹의 효소들은 glucose oxidase(GOD) 및 cellobiose : quinone oxidoreductase(CBQ)로서 feedback type의 효소들로서 목재고분자의 분해시 대사의 고리를 결합시켜 주는 매우 중요한 기능을 하는 효소군들이다. 그러나 이 이외에도 다른 분해기구가 밝혀지고 있으며 기타 효소들에 의한 리그노셀룰로오스의 분해반응기구의 해명에는 상당한 시간이 걸릴 것으로 사료된다.

• Environmental Engineering Research
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• v.19 no.2
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• pp.139-143
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• 2014

Catalytic degradation of pentachlorophenol in soil by heme and hydrogen peroxide has been hypothesized to occur through nonspecific catalytic reactions similar to those involving ligninase. The present study examines the evidence for a heme catalytic mechanism for the oxidation of organic compounds. In the presence of hydrogen peroxide, heme is converted to the ferryl heme radical (Hm-$Fe^{+4{\cdot}}$), which can oxidize organic compounds, such as 5-aminosalicylic acid (5-ASA). A second 5-ASA may later be oxidized by ferryl heme (Hm-$Fe^{+4}$), which reverts to the ferric heme state (Hm-$Fe^{+3}$) to complete the cycle. We believe that this catalytic cycle is involved in the degradation of hazardous pollutants, such as polycyclic aromatic hydrocarbons (PAHs). Remediation via heme catalytic reactions of PAHs in soil from a pole yard was evaluated, and about 96% of PAHs was found to disappear within 42 days after treatment with heme and hydrogen peroxide. In addition, benzo[a]pyrene and six other PAHs were undetectable among a total of 16 PAH compounds examined. Therefore, we propose heme catalysis as a novel technology for the remediation of hazardous compounds in contaminated soil.

• Journal of Microbiology and Biotechnology
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• v.21 no.2
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• pp.192-196
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• 2011

Microbial induction of rusty-root was proved in this study. The enzymes hydrolyzing plant structural materials, including pectinase, pectolyase, ligninase, and cellulase, caused the rusty-root in ginseng. Pectinase and pectolyase produced the highest rusty-color formation. Ferrous ion ($Fe^{+++}$) caused the synergistic effect on rusty-root formation in ginseng when it was used with pectinase. The effect of ferric ion ($Fe^{++}$) on rusty-root formation was slow, compared with $Fe^{+++}$, probably due to gradual oxidation to $Fe^{+++}$. Other metal ions including the ferric ion ($Fe^{++}$) did not affect rusty-root formation. The endophytic bacteria Agrobacterium tumefaciens, Lysobacter gummosus, Pseudomonas veronii, Pseudomonas marginalis, Rhodococcus erythropolis, and Rhodococcus globerulus, and the rotten-root forming phytophathogenic fungus Cylindrocarpon destructans, caused rusty-root. The polyphenol formation (rusty color) was not significantly different between microorganisms. The rotten-root-forming C. destructans produced large quantities of external cellulase activity (${\approx}2.3$ U[${\mu}m$/min/mg protein]), which indicated the pathogenecity of the fungus, whereas the bacteria produced 0.1-0.7 U. The fungal external pectinase activities (0.05 U) and rusty-root formation activity were similar to those of the bacteria. In this report, we proved that microbial hydrolyzing enzymes caused rusty-root (Hue value $15^{\circ}$) of ginseng, and ferrous ion worsened the symptom.

• Korean journal of applied entomology
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• v.45 no.3 s.144
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• pp.301-307
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• 2006

A ligniolytic bacterial strain was isolated from the digestive tract of a red dragonfly, Sympetrum dopressiusculum. It was identified as a Serratia marcescens HY-5 by 16S rDNA sequence analysis and physiological and biochemical analysis. The isolated strain showed proportional increase of ligninolytic activity to the cell growth in the culture media which include lignin compounds. It showed about 25-45% decomposition of lignin compound by 48 hr incubation especially, showed effective decomposition of monomer lignin compounds, vanillin and guaiacol, and a dimer, dealkaline lignin. PCR amplification of 16S rDNA followed by denaturing gradient gel electrophoresis analysis showed high density of S. marcescens HY-5 in the gut of the S. depressiusculum at both gut samples which collected at different site.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.305-311
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• 2001

Antifungal bacterium, Bacillus subtilis YS1 was isolated from Yusong hot spring showed broad antifungal spectrum against 12 kinds of plant pathogenic fungi and Candida albicans, animal pathogen. From the gamma($Co^{60}$) radiation sensitivity test, $D_10$ value was 2.08 kGy and it survived above 20 kGy of radiation dose. Several mutants were induced by gamma radiation. Among them, YS1-1009 mutant showed resistance against tebuconazole of herbicide, increased activity against Botryoshaeria dothidea and ligninase activity. YS67 mutant was antifungal deficient auxotrophic mutants(trp-pro-or arg-ura-). From this results, it suggested that gamma irradiation could be useful method for mutant induction.

• Journal of Microbiology
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• v.44 no.2
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• pp.177-184
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• 2006

The characteristic biodegradation of monomeric styrene by Phanerochaete chrysosporium KFRI 20742, Trametes versicolor KFRI 20251 and Daldinia concentrica KFRI 40-1 was carried out to examine the resistance, its degradation efficiency and metabolites analysis. The estrogenic reduction effect of styrene by the fungi was also evaluated. The mycelium growth of fungi differentiated depending on the concentration levels of styrene. Additionally P. chrysosporium KFRI 20742 showed superior mycelium growth at less than 200 mg/l, while D. concentrica KFRI 40-1 was more than 200 mg/l. The degradation efficiency reached 99 % during one day of incubation for all the fungi. Both manganese-dependent peroxidase and laccase activities in liquid medium were the highest at the initial stage of incubation, whereas the lowest was after the addition of styrene. However, both activities were gradually recovered after. The major metabolites of styrene by P. chrysosporium KFRI 20742 were 2-phenyl ethanol, benzoic acid, cyclohexadiene-1,4-dione, butanol and succinic acid. From one to seven days of incubating the fungi, the expression of pS2 mRNA widely known as an estrogen response gene was decreased down to the level of baseline after one day. Also, the estrogenic effect of styrene completely disappeared after treatment with supernatant of P. chrysosporium KFRI 20742 from one week of culture down to the levels of vehicle.

• Journal of the Korean Wood Science and Technology
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• v.39 no.6
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• pp.469-480
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• 2011

In this study, to determine the ligninase activity related to the PCBs degradation of Ceriporia sp. ZLY-2010, the protein contents and manganese peroxidase (MnP) and laccase activities during cultivation on shallow stationary culture (SSC) medium were observed. 4 PCB congeners were selected depending on the number of chlorine substituted on biphenyl. Furthermore, to examine the effects of cytochrome P450 monooxygenase, the inhibition of cytochrome P450 monooxygenase was evaluated by measuring the biodegradation rate when inhibitor such as 1-aminobenzotriazole was added. The extracellular protein contents were affected by PCB congeners in culture media. The total protein in the culture medium showed the biggest differences between the samples containing 2,2',4,4',5,5'-hexachlorobiphenyl and the control. On the other hand, MnP and laccase activity showed dominant increases within samples containing 4,4'-dichlorobiphenyl and 2,3',4',5-tetrachlorobiphenyl. Cytochrome P450 monooxygenase was inhibited by adding inhibitor, 1-aminobenzotriazole in low concentration. Only 2.73% of 2,3',4',5-tetrachlorobiphenyl was degraed on day 1, and biodegradation of 2,2',4,4',5,5'-hexachlorobiphenyl was inhibited as well, showing about 20% of biodegradation rate.

• The Korean Journal of Mycology
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• v.28 no.2
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• pp.97-102
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• 2000

The mycelial growth of Pleurotus ostreatus in compost is strongly stimulated by solid-state fermentation with thermophilic fungi which were isolated from oyster mushroom compost. The biochemical characteristics of these thermophilic fungi were investigated. Cellulase and ligninase activities were not detected by clear zone effect on CMC and lignin media. All of thermophilic fungi grew well with high mycelial density on xylan media and the growing rate of Sepedonium sp. S-2 observed very high. In results of MUF-test, extracellular enzyme activity of Sepedonium sp. S-2, and S-5 measured very high. On the compost after high temperature fermentation with Sepedonium sp. S-2 and S-5, the mycelial growing rate of Pleurotus ostreatus was increased about 50% and it also showed the inhibiting effect on mycelial growth of Trichoderma sp. SJG-51. Isolated thermophilic fungi, Sepedonium sp. S-2 and S-5 were expected as very useful organism for making oyster mushroom compost.