• Korean Journal of Microbiology
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• v.33 no.1
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• pp.43-48
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• 1997

여러가지 난분해성 물질에 대한 생분해능을 지닌 백색부후균에 의한 매립지 침출수의 탈색을 조사하였다. 국내에서 분리한 Coriolus versicolor KR-11W와 Irpex lacteus KR-39W가 이제까지 주로 연구되어 온 Phanerochaete chrysosporium보다 높은 탈색능을 나타내었는데 I. lacteus KR-39W는 산소공급시 10%의 침출수가 함유된 YMG 배지의 진탕배양에서 85%의 색도제거율을 나타내었으며 최소배지에서도 80%의 탈색율을 보였다. P. chrysosporium에 의한 리그닌 분해능 및 분해효소 생성 보고들과 달리 진탕배양이 정치배양보다 탈색능이 높았으며 산소공급은 색도제거에 증가효과가 있었다. 균체 접종량(10-30%)과 온도(25,37.deg. C)는 탈색에 큰 차이를 보이지 않았으나 탄소원과 질소원의 농도는 상당한 영향을 나타내었다. 리그닌 분해효소군의 여러 가지 inducer와 cofactor를 C. versicolor KR-11W 배양에 첨가한 결과 많은 경우 균접종 대조군보다 2배 이상의 탈색율과 lignin peroxidase 활성의 증가를 보였으며 FeS $O_{5}$ 첨가시에는 최대 2.9배의 증가를 나타내었다. 탈색에 관여하는 효소군은 접종물에 이미 어느 정도 존재할 수 있으며 배지 및 배양조건에 따라 그 생성이 변화할 수 있으므로 이런 조건들을 잘 맞출 경우 보다 높은 탈색능이 기대된다.

• Journal of Microbiology and Biotechnology
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• v.22 no.2
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• pp.239-243
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• 2012

Degradation of butylbenzyl phthalate (BBP) by the white rot fungus Pleurotus ostreatus and the activities of some degrading enzymes were examined in two different media containing 100 mg/l of the compound. P. ostreatus pre-grown for 7 days in complex YMG medium was able to completely degrade BBP within an additional 24 h but degraded only 35 mg/l of BBP in 5 days of incubation in minimal medium. Fungal cell mass in the culture in YMG medium was higher in the presence than in the absence of BBP. The esterase activity of the fungal culture in YMG medium was higher than that in minimal medium and increased with the addition of BBP. On the contrary, laccase activity was higher in minimal medium and it did not increase upon the addition of BBP. General peroxidase activity increased for a few days after the addition of BBP to both media. The degradation of BBP and its metabolites by P. ostreatus thus may be attributed mostly to esterase rather than lignin-degrading laccase. In addition, the activities of the enzymes involved in BBP degradation and their changes varied significantly in the different media and culture conditions.

• The Plant Pathology Journal
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• v.37 no.3
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• pp.205-214
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• 2021

The use of the supernatant from a Bacillus subtilis culture mixed with sodium bicarbonate was explored as a means of controlling stem brown spot disease in dragon fruit plants. In in vitro experiments, the B. subtilis supernatant used with sodium bicarbonate showed a strong inhibition effect on the growth of the fungus, Neoscytalidium dimidiatum, the agent causing stem brown spot disease and was notably effective in preventing fungal invasion of dragon fruit plant. This combination not only directly suppressed the growth of N. dimidiatum, but also indirectly affected the development of the disease by eliciting the dragon-fruit plant's defense response. Substantial levels of the pathogenesis-related proteins, chitinase and glucanase, and the phenylpropanoid biosynthetic pathway enzymes, peroxidase and phenyl alanine ammonia-lyase, were triggered. Significant lignin deposition was also detected in treated cladodes of injured dragon fruit plants in in vivo experiments. In summary, B. subtilis supernatant combined with sodium bicarbonate protected dragon fruit plant loss through stem brown spot disease during plant development in the field through pathogenic fungal inhibition and the induction of defense response mechanisms.

• Journal of the Korean Wood Science and Technology
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• v.34 no.4
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• pp.46-53
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• 2006

This study was to screen white-rot fungi possesing strong lignin degrading enzymes, glucose-1 oxidase (GOD), laccase (LAC) and Mn-peroxidase (MnP), based on their decolorization activity of Remazol Brilliant Blue R (RBBR). In the midst of 20 tested fungi, 9 isolates were shown 4 kinds of activities such as RBBR decolorization, GOD, LAC and MnP. Relatively high active strains were identified as Phlebia radiata, Trametes versicolor, Abortiporus biennis, Gleophyllum odoratum and Cerrena unicolor. In particular, T. versicolor, G. odoratum, and C. unicolor, which have high activities of LAC, were used to confirm the optimal temperature and pH and to evaluate the effect of inducer, 2,5-xylidine on their LAC activity. The optimum temperatures for mycelial growth were $28^{\circ}C$ for T. versicolor and G. odoratum, and $25^{\circ}C$ for C. unicolor. The optimum pH for mycelial growth was 5.5. Three strains showed the increase of LAC enzyme activity by the addition of 2,5-xylidine. T. versicolor had the highest LAC activity of $22,700nkat/{\ell}$, corresponding to 11.3 times, G. odoratum $15,400nkat/{\ell}$, 9 times and C. unicolor $17,330nkat/{\ell}$, 5.5 times higher than those of the control.

• The Korean Journal of Mycology
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• v.32 no.2
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• pp.112-118
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• 2004

Laccase produced by Trametes hirsuta S1 isolated from Korea was partially purified and characterized using ultrafiltration, anion exchange chromatography and affinity chromatography. The laccase was produced as the predominant extracellular enzyme during primary metabolism. Neither lignin peroxidase nor veratryl alcohol oxidase (VAO) were detected in the culture fluid. Addition of 2,5-xylidine enhanced 4-fold laccase production. Purified laccase was a single polypeptide having a molecular mass of approximately 66 kDa, as determined by SDS-polyacrylamide gel electrophoresis, and carbohydrate content of 12%. $K_{m}\;and\;V_{max}$ values for laccase with ABTS [2,2-azinobis (3-ethylbenzthiazoline 6-sulfonic acid)] as a substrate (Lineweaver-Burk plot) was determined to $51.2\;{\mu}M\;and\;56.8\;{\mu}mole$, respectively. The optimal pH for laccase activity was found to be 3.0. The enzyme was very stable for 1 hour at $50^{\circ}C$. Half-life ($t_{1/2}$) of the enzyme was about 20 min at $70^{\circ}C$. Spectroscopic analysis of purified enzyme indicated that the enzyme was typical of copper-containing protein. Substrate specificity and inhibitor studies for laccase also indicated to be a typical fungal laccase. The N-terminal amino acid sequence of the T. hirsuta S1 laccase showed 100% of homology to those of laccase from C. hirsutus.

• Journal of Mushroom
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• v.17 no.4
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• pp.247-254
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• 2019

Trametes hirsuta, a white rot fungus, exhibits the ability to degrade synthetic aromatic dyes such as congo red (CR), methylene blue (MB), crystal violet (CV), and remazol brilliant blue R (RBBR). The mycelia of T. hirsuta degraded RBBR and CR more efficiently than CV and MB in the PDB liquid medium (supplemented with 0.01% 4 aromatic dyes). In these mycelia the activities of three ligninolytic enzymes-laccase, manganese peroxidase (MnP), and lignin peroxidase (LiP)-were observed. Among these, laccase was identified to be the major enzyme responsible for the degradation of the four aromatic dyes. The degradation of bisphenol A was also investigated by culturing the mycelia of T. hirsuta in YMG medium supplemented with 100 ppm bisphenol A. The mycelia of T. hirsuta were found to degrade bisphenol A by 71.3, 95.3, and 100 % within incubation periods of 12, 24, and 36 hr, respectively. These mycelia also showed ligninolytic enzyme-like activities including those similar to laccase, MnP, and LiP. Therefore, these results indicate that T. hirsuta could emerge as a potential tool for the remediation of environmental contamination by aromatic dyes and bisphenol A.

• Mycobiology
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• v.46 no.3
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• pp.224-235
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• 2018

Temperature is an important environmental factor that can greatly influence the cultivation of Auricularia cornea. In this study, lignin peroxidase, laccase, manganese peroxidase, and cellulose in A. cornea fruiting bodies were tested under five different temperatures ($20^{\circ}C$, $25^{\circ}C$, $30^{\circ}C$, $35^{\circ}C$, and $40^{\circ}C$) in three different culture periods (10 days, 20 days and 30 days). In addition, the V4 region of bacterial 16S rRNA genes in the substrate of A. cornea cultivated for 30 days at different temperatures were sequenced using next-generation sequencing technology to explore the structure and diversity of bacterial communities in the substrate. Temperature and culture days had a significant effect on the activities of the four enzymes, and changes in activity were not synchronized with changes in temperature and culture days. Overall, we obtained 487,694 sequences from 15 samples and assigned them to 16 bacterial phyla. Bacterial community composition and structure in the substrate changed when the temperature was above $35^{\circ}C$. The relative abundances of some bacteria were significantly affected by temperature. A total of 35 genera at five temperatures in the substrate were correlated, and 41 functional pathways were predicted in the study. Bacterial genes associated with the membrane transport pathway had the highest average abundance (16.16%), and this increased at $35^{\circ}C$ and $40^{\circ}C$. Generally, different temperatures had impacts on the physiological activity of A. cornea and the bacterial community in the substrate; therefore, the data presented herein should facilitate cultivation of A. cornea.

• Journal of Korea Foresty Energy
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• v.23 no.2
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• pp.21-28
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• 2004

Three different strains of Lentinula edodes, Sanlim 5-Ho, Sanlim 6-Ho and Nongki 3-Ho, were cultured in the sawdust media of Mongolian oak(Quercu mongolica Fisch) for 90 days under dark and light conditions(each 30 days) and fruiting period(30 days). Weight loss of sawdust media was determined after fungal cultures and the contents of ergosterol in fungal mycelia were quantified by HPLC analysis followed by solvent extraction. Compared with the two other fungal strains$(8\%)$, weight loss of Sanlim 5-Ho was slightly lowered to $7\%$. The level of ergosterol content, a parameter for fungal growth, was continuously enhanced in Sanlim 5-Ho for dark and light incubation periods. However, Sanlim 6-Ho and Nongki 3-Ho recorded the maximized fungal growth under light condition. In fruiting periods the ergosterol contents were lowered in the three strains. Intra- and extracellular enzymes during cultural and fruiting periods were also characterized. The activity of Mn-peroxidase and laccase, which are characteristics enzymes for white rot fungi as lignin degrading enzymes, were determined as a high level overall the periods. As cellulose degrading indicators, the activity of CMCase, avicelase, xylanase and glucanase were detectable in initial incubation period.

• Journal of Mushroom
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• v.20 no.2
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• pp.86-91
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• 2022

Pleurotus eryngii, a white rot fungus, produces two extracellular lignin-degrading enzymes, laccase and manganese peroxidase (MnP). Owing to these enzymes, P. eryngii efficiently degrades synthetic chemicals such as azo, phthalocyanine, and triphenyl methane dyes. In this study, we investigated the degradation processes of four aromatic dyes, congo red (CR), methylene blue (MB), crystal violet (CV), and malachite green (MG), by P. eryngii under solid and liquid culture conditions. CR and MG were the most quickly degraded under solid and liquid culture conditions, respectively. However, compared to CR, CV, and MG, MB was not degraded well under both culture conditions. The activities of ligninolytic enzymes (laccase and MnP) were also investigated. Laccase was identified to be the major enzyme for dye degradation. A positive relationship between decolorization and enzyme activity was observed for CR, MB, and CV degradation. In contrast, decolorization of MG ensued after high enzyme activity. These results indicate that the degradation process differs between MG and the other aromatic dyes. Therefore, P. eryngii could be a potential tool for the bioremediation of synthetic aromatic dye effluent.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.704-708
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• 2001

The effect of nutrient nitrogen on the degradation of pentachlorophenol (PCP) by Phanerochaete chrysosporium in a liquid culture was investigated. PCP disappeared at almost the same rate in both nutrient nitrogen-sufficient (NS) and -limited (NL) sttionary cultures. However, more pentachloroanisole (PCA) was accumulated in the NS culture than in the NL culture. The effect of nitrogen on the degradation of PCA was also tested in both cultures. PCA disappeared faster in the NL culture than in the NS culture, indicating that the lower accumulation of PCA during the degradation of PCP in the NL culture was due to the faster degradation of PCA in the NL culture than in the NS culture. In another experiment, PCA was added to shaking cultures rather than stationary cultures to search for any other metabolite(s). While no other metabolite but PCA was found in the NS stationary culture, 2,4,5,6-tetrachloro-2,5-cyclohexadiene-1,4-dione(TCHD) was found as the only indentifiable product in the NL shaking culture. Thus, PCP would appear to be metabolized to TCHD via PCa or directly oxidized to TCHD by lignin peroxidase. Since all the above results indicate that no innocuous metabolite was formed during the degradation of PCP by the fungus, it is quite feasible to use the fungus in the biotreatment of PCP.