• Mycobiology
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• 제40권4호
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• pp.263-264
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• 2012

Sclerotium rot was found on Cymbidium orchids at Seosan-si, Chungcheongnam-do, Korea, in July, 2010. Symptoms occurred on low leaves, which turned yellowish, after which the entire plant wilted. Severely infected plants were blighted and eventually died. White mycelial mats and sclerotia appeared on pseudobulbs. Based on the mycological characteristics and pathogenicity, the causal fungus was identified as Sclerotium rolfsii. This is the first report of new Sclerotium rot on Cymbidium spp. caused by S. rolfsii in Korea.

• Mycobiology
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• 제33권4호
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• pp.240-242
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• 2005

A soft rot of fruits caused by Mucor racemosus occurred on cherry tomato collected in Agricultural Products Wholesale Market in Jinju, Korea. The disease infection usually occurred wounded areas after cracking of fruits. At first, the lesions started with water soaked and rapidly softened and diseased lesion gradually expanded. Colonies were white to brownish to gray in color. Sporangia were $32{\sim}54\;{\mu}m$ in size and globose in shape. Sporangiophores were $8{\sim}14\;{\mu}m$ in width. Sporangiospores were $5{\sim}12\;{\times}\;4{\sim}8\;{\mu}m$ in size, ellipsoidal to subglobose in shape. Columella was $27{\sim}42\;{\mu}m$ in size, obovoid, ellipsoidal, cylindrical-ellipsoidal, slightly pyriform in shape. Chlamydospores were numerous in sporangiophores and barrel-shaped when young, subglobose in old cultures. Optimum growth temperature was about $25^{\circ}C$. The fungus was identified as M. racemosus Fres.. This is the first report of soft rot on cherry tomato caused by M. racemosus in Korea.

• Mycobiology
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• 제40권3호
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• pp.214-216
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• 2012

Soft rot on banana fruit caused by Rhizopus oryzae was identified for the first time in Korea. Colonies were white to light brown and formed numerous sporangiospores. Optimum temperature for mycelial growth was $30^{\circ}C$. Sporangia were globose and $30{\sim}200{\mu}m$. Sporangiophores were usually straight, $8{\sim}20{\mu}m$, and rhizoids usually in groups of 3~5. Columella were globose to sub-globose and $90{\sim}110{\mu}m$. Sporangiospores were sub-globose or oval and $4{\sim}10{\mu}m$. Based on its mycological characteristics, molecular analysis, and pathogenicity to host plants, this fungus was identified as Rhizopus oryzae Went & Prisen Geerligs. This is the first report of soft rot on banana caused by Rhizopus oryzae in Korea.

• 임산에너지
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• 제17권1호
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• pp.56-70
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• 1998

This study was carried out to investigate the structural characteristics of kraft lignin and the wood degrading characteristics, the productivity of ligninolytic enzymes and the enzymatic degradation of kraft lignin by white-rot fungi. To purify kraft lignin, precipitation of kraft pulping black liquors of pitch pine meal was done by titration with lN $H_{2}SO_{4}$ reaching to pH 2, and isolation of the precipitates done by centrifugation. The isolated precipitates from pitch pine were redissloved in lN NaOH, reprecipitated by titration with lN $H_{2}SO_{4}$, washed with deionized water, and kept ofr analysis after freeze drying. Fractionation of the precipitates in solution by successive extraction with $CH_{2}Cl_{2}$ and MeOH, and the fractionates were named SwKL, SwKL I, SwKL II, and SwKL III for pitch pine kraft lignin. The more molecular weights of kraft lignin increased, the less phenolic hydroxyl groups and the more aliphatic hydroxyl groups. Because as the molecular weights increased, the ratio of etherified guaiayl/syringyl(G/S ratio) and the percentage were increased. The spectra obtained by 13C NMR and FTIR assigned by comparing the chemical shifts of various signals with shifts of signals from autherized ones reported. The optimal growth temperature and pH of white-rot fungi in medium were $28^{\circ}C$ and 4.5-5.0, respectively. Especially, in temperature and pH range, and mycelial growth, the best white-rot fungus selected was Phanerochaete chrysosporium for biodegradation. For the degradation pathways, the ligninolytic fungus jcultivated with stationary culture using medium of 1% kraft lignin as a substrate for 3 weeks at $28^{\circ}C$. The weight loss of pitch pine kraft lignin was 15.8%. The degraded products extracted successively methoanol, 90% dioxane and diethyl ether. The ether solubles were analyzed by HPLC. Kraft lignin degradation was initiated in $\beta$-O-4 bonds of lignin by the laccase from Phanerochaete chrysosporium and the degraded compounds were produced from the cleavage of $C\alpha$-$C\beta$ linkages at the side chains by oxidation process. After $C\alpha$-$C\beta$ cleavage, $C\alpha$-Carbon was oxidized and changed into aldehyde and acidic compounds such as syringic acid, syringic aldehyde and vanilline. And the other compound as quinonemethide, coumarin, was analyzed. The structural characteristics of kraft lignin were composed of guaiacyl group substituted functional OHs, methoxyl, and carbonyl at C-3, -4, and -5 and these groups were combinated with $\alpha$ aryl ether, $\beta$ aryl ether and biphenyl. Kraft lignin degradation pathways by Phanerochaete chrysosporium were initially accomplished cleavage of $C\alpha$-$C\beta$ linkages and $C\alpha$ oxidation at the propyl side chains and finally cleavage of aromatic ring and oxidation of OHs.

• 식물병연구
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• 제17권3호
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• pp.396-398
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• 2011

2010년 6월 중순 경남 진주시 농산물도매시장에 유통 판매중인 산딸기에서 이상증상이 발생하였다. 병징은 과실표면에 상처 또는 물러진 과실부분이 수침 상으로 물러지면서 빠르게 부패되었다. 균총은 처음 흰색에서 연한회색으로 되고 검은색의 포자낭을 많이 형성하였으며 균사생육 적온은 $30^{\circ}C$이었으며 $37^{\circ}C$에서도 성장하였다. 포자낭은 검은색으로 구형이며 크기는 40-210 ${\mu}m$이었다. 포자낭경은 처음 흰색에서 연한 갈색을 나타내며 폭은 8-20 ${\mu}m$이었다. 주축은 구형 또는 반구형이며 크기는 85-120 ${\mu}m$이었다. 포자낭 포자는 담갈색으로 단포이며 구형 또는 장방형이고 불규칙한 것도 있으며 크기는 5-10 ${\mu}m$ 이었다. 따라서 산딸기 과실에 발생한 병징과 병원균의 균학적 특징, ITS 염기서열 분석, 그리고 병원성을 검정한 결과, 본 병을 Rhizopus oryzae Went & Prinsen Geerlings 에 의한 산딸기 무름병으로 명명할 것을 제안한다.

• 한국미생물·생명공학회지
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• 제31권3호
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• pp.301-306
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• 2003

Twenty-one different fungi were tested for their ability to decolorize a wide range of structurally different dyes. Twenty fungal strains were isolated from fruiting bodies which were collected at the Kwangneung National Arboretum, Korea. One fungal strain were isolated from a rotting wood at Soongsil University, Korea. Nine kinds of dyes were used: three anthraquinone dyes and six azo dyes. The five fungal strains, Laetiporus sulphureus, Polyporus arcularius. Auricularia polytricha, Stereum ostrea, and Bjerkandera sp. UK-l showed decolorization ability. Except Auricularia polytricha, the four fungal strains were wood rotting fungi, and belonged to Aphyllophorales. Bjerkandera sp. UK-I, which was a white rot fungus, could decolorize all kinds of dyes tested in this study, indicating this fungus is one of candidates for applying in biological methods of dye waste treatment.

• Journal of the Korean Wood Science and Technology
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• 제44권1호
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• pp.124-134
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• 2016

본 연구에서는 백색부후균 Abortiporus biennis를 이용하여 유기용매 리그닌의 생물학적 변환을 시도함으로써, 생물학적 변환 기작을 이해하고, 상업적 활용을 위해 유기용매 리그닌의 저분자화를 유도하고자 하였다. 질소제한 배지에서 A. biennis는 주로 유기용매 리그닌의 중합반응을 유도하면서, 분자량을 급격히 증가시켰으며, 배양일에 따라 구조적 차이를 야기하였다. 배양 초기, ether 결합의 분해를 통해 phenolic OH 함량이 증가한 반면, 배양 후기에는 ether 결합이 증가함에 따라 phenolic OH 함량이 감소하였다. 이러한 결과를 바탕으로, 유기용매 리그닌의 탈중합을 유도하기 위해 환원제인 ascorbic acid를 첨가하여 유기용매 리그닌의 구조 변화 및 변환 산물을 분석하였다. 결과적으로, 환원제의 첨가에 의해 유기용매 리그닌의 분자량은 소폭 증가하였지만, 환원제 무첨가 실험에 비해 그 증가 폭이 현저히 감소하였다. 또한 배양액 내 리그닌 올리고머의 경우, 배양 10일째 환원제를 첨가한 실험구에서 중량 평균 분자량 381 Da, phenolic OH 함량 38.63%을 나타냈으며, 이는 저분자화된 형태로 상업적 활용 가치가 높다고 사료된다. 결론적으로, A. biennis의 효소 시스템은 유기용매 리그닌의 분해보다 중합을 야기하였으며, 환원제의 첨가를 통해 배양액 내 리그닌 올리고머의 저분자화 및 phenolic OH 함량 증가를 유도할 수 있었다.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권2호
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• pp.96-99
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• 2006

In this study, we have attempted to determine the optimum concentration of inducers responsible for efficient laccase production by the white-rot fungus, Trametes sp. Variations in laccase activity were investigated with changing concentrations of 2,5-xylidine, syringaldazine, ABTS, and guaiacol. Enhancement of peak laccase activity was achieved via the combination of 2,5-xylidine with ABTS, syringaldazine, or guaiacol, resulting in increases of up to 359, 313, and 340%, respectively, as compared to control values. Among the tested inducers, the addition of 0.1mM of ABTS coupled with 1.0mM of 2,5-xylidine in the medium after 24 h of cultivation proved optimal with regard to laccase enzyme production.

• Journal of Microbiology
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• 제42권2호
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• pp.94-98
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• 2004

Phenanthrene is a three-ring polycyclic aromatic hydrocarbon and commonly found as a pollutant in various environments. Degradation of phenanthrene by white rot fungus Trametes versicolor 951022 and its laccase, isolated in Korea, was investigated. After 36 h of incubation, about 46％ and 65％ of 100 mg/l of phenanthrene added in shaken and static fungal cultures were removed, respectively. Phenanthrene degradation was maximal at pH 6 and the optimal temperature for phenanthrene removal was 30$^{\circ}C$. Although the removal percentage of phenanthrene was highest (76.7％) at 10 mg/1 of phenanthrene concentration, the transformation rate was maximal (0.82 mg/h) at 100 mg/L of phenanthrene concentration in the fungal culture. When the purified laccase of T. versicolor 951022 reacted with phenanthrene, phenanthrene was not transformed. The addition of redox mediator, 2,2'-azino-bis-(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) or 1-hydroxybenzotriazole (HBT) to the reac-tion mixture increased oxidation of phenanthrene by laccase about 40％ and 30％, respectively.

• 식물병연구
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• 제9권4호
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• pp.221-223
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• 2003

2002년 경상남도농업기술원 함양약초시험 포장에 재배중인 꽃범의꼬리에서 이상증상이 발생하였다. 병징은 지제부의 줄기가 수침상으로 물러지고 부패하면서 암갈색으로 변하고 그 위에 흰색의 곰팡이가 솜털처럼 생기고, 병반 부위와 토양 표면에 갈색의 둥근 균핵이 많이 형성된다. 병원균의 균사생장 및 균핵형성은 PDA배지에 배양시 $30^{\circ}C$에서 가장 양호하였다. 균핵은 갈색 또는 암갈색으로 크기는 1${\sim}$3 mm이었다. 균사 특유의 clamp connection이 관찰되었고 균사 폭은 3.6${\sim}$9.4 ${\mu}m$이었다. 본 병원균을 Sclerotium rolfsii로 동정하였으며 꽃범의꼬리 흰비단병으로 명명할 것을 제안한다.