• Title/Summary/Keyword: white-rot fungi

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Cloning of a Manganese Peroxidase cDNA Gene Repressed by Manganese in Trametes versicolor

  • Kim Yongho;Yeo Sumin;Kum Joohee;Song Hong-Gyu;Choi Hyoung T.
    • Journal of Microbiology
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    • v.43 no.6
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    • pp.569-571
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    • 2005
  • White-rot fungi have the following enzyme systems for lignin degradation: laccase, lignin peroxidase and manganese peroxidase. There are other types of peroxidases related to lignin degradation, one of which we have cloned a cDNA gene of manganese-repressed peroxidase (MrP) in Trametes versicolor isolated in South Korea. The mrp transcript level has been decreased by $1{\mu}M\;of\;Mn^{2+}$.

Occurrence of Rhizopus Soft Rot on Squash (Cucurbita moschata) Caused by Rhizopus stolonifer in Korea

  • Kwon, Jin-Hyeuk;Kang, Soo-Woong;Park, Chang-Seuk
    • The Plant Pathology Journal
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    • v.16 no.6
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    • pp.321-324
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    • 2000
  • season of 2000. The disease infection usually started from flower, peduncle and young fruits, then moved to flower stalk, stem and leaves. At first, the lesions started with water-soaked, rapidly softened, and then the area gradually expanded. In severely affected film house, the rate of infected fruits reached to 28.6%. Numerous sporangiospores were formed on the diseased fruits, flower stalk, stem and leaves. Most of the sporangiospores were appeare to be rapidly dispersed in the air. The mycelia grew on the surface of host and formed stolons. Colonies on potato dextrose agar were cottony at first brownish black at maturity. Sporangia were 125.3${\times}$294.2 ${\mu}$m. globose or sub-globose with somewhat flattened base. White at first the black, many spored, and are never overhanging. Sporangiophores were 2.7-6.8${\times}$12.9-33.9 ${\mu}$m, smooth-walled, non-septate, light brown, simple, long, arising in groups of 3-5 from stolons opposite rhizoids. Sporangiophores were 8.6-21.1${\times}$6.41-1.7 ${\mu}$m, irregular, round, oval, elongate, angular and brownish-black streaked. Columella were 63.8${\times}$140.4 ${\mu}$m. brownish gray, umberella-shaped when dehisced. The causal organism was identified as Rhizopus stolonifer Lind on the basis of the morphological characteristics of the fungus. Rhizopus soft rot on squash (Cucurbita moschata) caused by the fungi has not been previously reported in Korea.

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Occurrence of Sclerotinia Rot of Crisphead Lettuce Caused by Sclerotinia sclerotiorum and Its Pathogenicity (Sclerotinia sclerotiorum에 의한 결구상추 균핵병(Sclerotinia rot)의 발생과 병원성)

  • Baek, Jung-Woo;Kim, Han-Woo;Kim, Hyun-Ju;Park, Jong-Young;Lee, Kwang-Youll;Lee, Jin-Woo;Jung, Soon-Je;Moon, Byung-Ju
    • Research in Plant Disease
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    • v.10 no.4
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    • pp.324-330
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    • 2004
  • This studies were investigated the occurrence of sclerotinia rot at the crisphead lettuce field in Uiryeong-Gun, Gyeongsangnam-Do from January to May in 2003. Average incidence rates of sclerotinia rot on crisphead lettuce was up to 21.9% at the five plastic houses. A total of 140 isolates of Sclerotinia sp. were obtained from diseased leaves of crisphead lettuce. Among them, the fungi YR-1 was isolated, which showed highly virulent on the whole plant. the YR-1 was identified as Sclerotinia sclerotiorum based on the formation, color, shape and size of sclerotium and apothecium. For the pathogenicity test, the most suitable inoculum quantity of YR-1 strain was selected as the triturated mycelial suspension of $A_{550}$=0.8, 40 ml showing disease incidence of 94%, and the symptom showed as same as at the fields, the leaves and stem had rotten and developed white downy mycelial at the diseased lesion on the leaves and stems, and produced black and irregular sclerotinia. This is the first report on the pathogenicity test using by triturated mycelial suspension-inoculum of the pathogen for the sclerotinia rot of crisphead lettuce.

Occurrence of Bunch Rot Disease Caused by Aspergillus tubingensis on Shine Muscat Grape (Aspergillus tubingensis에 의한 샤인머스켓 포도송이썩음병(가칭)의 발생)

  • Kim, Young Soo;Kwon, Hyeok Tae;Hong, Seung-Beom;Jeon, Yongho
    • Research in Plant Disease
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    • v.25 no.4
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    • pp.220-225
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    • 2019
  • During the year 2018, the symptoms of bunch rot on Shine Muscat (Vitis vinifera L.) were observed in Kimcheon-si, Gyeongbuk province in Korea. The disease appears on the Shine Muscat as a black rot due to prolific fungal sporulation after it has invaded into the Shine Muscat which look completely empty and dryness. Colonies of these fungi are present on the Shine Muscat skin from fruit setting and increase in amount from early season to harvest, while become peak at ripening stage. To isolate the causal agent, small fragments (2 to 3 mm) of decayed tissue from the lesion margin were placed onto potato dextrose agar (PDA) plates. Fungal colonies on PDA produced dense white aerial mycelium and then covered with dark black conidial heads. These heads were large and radiate, and vesicles were globose (2.12-32.0×2.0-3.1 ㎛). Based on morphological and cultural characteristics, this fungus was identified as Aspergillus tubingensis. To confirm its identity, the internal transcribed spacer, β-tubulin, and RNA polymerase II was sequenced for molecular identification. BLAST search indicated 99% identity with A. tubingensis. The pathogenicity test on healthy grape of Shine Muscat produced bunch rot, as the original symptoms. To select effective fungicides for the control of brunch rot, an in vitro antifungal activity of seven fungicides were evaluated against the growth of A. tubingensis. Five fungicides (dipenoconazole, tebuconazole, metconazole, iminoctadine, and captan) exhibited significantly strong suppression of the mycelial growth of A. tubingensis.

The physiological and degradational characteristics of Fomers fomentarius (말굽버섯균의 생리적 특성과 부후특성)

  • Kim, Yu-I;Chai, Jyung-Ki
    • Journal of Mushroom
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    • v.2 no.4
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    • pp.200-206
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    • 2004
  • The optimal temperature for mycelial growth the F. fomentarius was $30^{\circ}C$ and the range of the temperature for mycelial growth wsa about 10~30. The optimal pH for the growth was 4.0. The percentage of weight loss percentage wsa 17.4%. The percentage of WEC extractives wsa increased to 2.24%. The observation of micromorphological showed that the detected cell wall were erosive and thinning as typical degradation pattern of white-rot fungi.

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Bio-Soda Pulping of Rice Straw with Pleurotus cornucopiae under Atmospheric Pressure

  • Ju, Yong-Chan;Kang, Jin-Ha
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.35 no.5
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    • pp.62-71
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    • 2003
  • This study was carried out to develop the bio-chemical pulping method to enhance the energy saving and decrease the capital cost through the soda pulping under atmospheric pressure ($100^{\circ}C$). Nonwood substrates, rice straw, were pretreated by white-rot fungi, Pleurotus cornucopiae. Several basic pieces of data that can be applied in soda pulping were acquired. The results of this study were as follows. Under the conditions without any nutrients or with glucose, N and glucose + N, the weight losses of rice straws inoculated by Pleurotus cornucopiae were 12.1∼32.6 %, 12.0∼26.3 %, 13.0∼25.4 % and 15.3∼24.7 % for 5, 10, 15, 20, 25 and 30 days incubation periods respectively. The more the fungal incubation was extended, the more the weight losses were gained. The yield of untreated rice straw was 54.8 % after pulping. When any nutrients was not added or glucose, N and glucose + N were added for the pretreatment, the total yields were ranged to 57.3∼42.9 %, 51.0∼43.3 %, 51.7∼43.9 % and 52.1∼46.1 % for 5 different incubation periods respectively. The yields were gradually decreased based on the extending of the incubation periods. The physical properties of the rice straw soda pulp without fungal treatment, the density, breaking length, burst index, tear index and folding endurance were 0.24g/㎤, 2.32 Km, 0.91 kPaㆍ$m^2$/g, 46.7 mNㆍ$m^2$/g and 21 times, respectively. In the case of pretreatment without any nutrients or with glucose, N and glucose + N as nutrients, the density was 0.24g/㎤, the breaking length was 3.30∼6.46 Km, the burst index was 1.36∼3.01 kPaㆍ$m^2$/g, the tear index was 33.0∼57.0 mNㆍ$m^2$/g and the folding endurance was 14∼381 times at most incubating periods, when pulping was done. The physical properties were increased as the incubation duration was extended. Especially, when N and glucose + N were added, the physical properties showed superior results during each incubation period.

Changes in Activities of Lignin Degrading Enzymes and Lignin Content During Degradation of Wood Chips by Polyporus brumalis (겨울우산버섯에 의한 목재칩의 리그닌 분해 효소 활성 및 리그닌 함량 변화)

  • Cho, Myung-Kil;Ryu, Sun-Hwa;Kim, Myungkil
    • Journal of the Korean Wood Science and Technology
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    • v.40 no.6
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    • pp.424-430
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    • 2012
  • In this study, laccase activity, rate of weight loss and degree of lignin degradation of pine wood chips were determined during the liquid and solid state incubation with Polyporus brumalis. The results showed that laccase enzyme activity at untreated wood chip was gradually decreased after 20 days, but enzyme activity with wood chip treatment showed 10 times higher than untreated ones at 60 incubation days. Rate of weight losses of pine chip and rate of lignin loss were 23.4% and 6.3% by P. brumalis during 80 incubation days. Gene expression of pblac1 from P. brumalis was 3 times increased under pine chip treatment at 40 incubation days. Consequently, laccase activity of white rot fungi, P. brumalis, was increased at incubation with wood chip and pblac1 gene was important factor of lignin degradation. Therefore, to regulate lignin degrading enzyme gene expression by using the tools of biotechnology will be able to develop superior strains and it will be useful for pretreatment of lignocellulosic biomass at bioethanol production.

Cultural Conditions for the Mycelial Growth of Phellinus spp. (진흙버섯속의 배양적 특성)

  • Heo, Byong-Soo;Lee, Kang-Soo;Park, Seong-Cheol;Lee, Yang-Soo
    • The Korean Journal of Mycology
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    • v.32 no.2
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    • pp.134-137
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    • 2004
  • This study was carried out to determine the optimum culture conditions for Phellinus spp. known as white rot fungi showing anti-cancer activity. The optimum solid medium for mycelial growth at $25^{\circ}C$ was potato dextrose agar medium and optimum pH range was $6.0{\sim}8.0$, while all species showed reduced or no growth at pH 4.0. Most species showed good growth at $25{\sim}30^{\circ}C$. Out of 10 species of Phellinus examined, P. biscuspidatus was the best growing fungus in the range of pH $6.0{\sim}7.0$ based on mycelial density. Three species such as P. biscuspidatus, P. johnsonianus and P. lloydii could be grouped in mesophile fungi, showing $30{\sim}35^{\circ}C$ optimum temperature.

Studies on Antimicrobial and Antioxidative Activities of Extracts from Magnoliaceae (목련과 식물의 항균 및 항산화활성)

  • Lee, Sung-Suk;Lee, Hak-Ju
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.6
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    • pp.579-586
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    • 2010
  • This study was carried out to evaluate the antifungal and antioxidative activities of ethanol extracts from Magnoliaceae to investigate the possibility for the natural fungicides and food preservatives. The antifungal activities of ethanol extracts were evaluated as a hyphal growth inhibition rate using four plant pathogenic and five wood rot fungi. The high inhibition activity on the growth of fungi was shown in bark of Magnolia obovata that indicated more than 50% hyphal growth inhibition rate except Trametes versicolor, one of the white rot fungi. The antifungal activity was the highest in the ethanol extracts from M. obovata and the following was in order of M. kobus and M. sieboldii. The extract from bark in M. obovata showed higher antifungal activity than that from wood in the same species. Especially, the extracts from flower of M. denudata and M. liliflora indicated the high antifungal activities, while the other portions of same plants showed the low activities. On the other hand, a free radical scavenging method was adopted with 1,1-diphenyl-2-picrylhydrohydrazyl (DPPH) in order to test the antioxidative activities of ethanol extracts. The free radical scavenging activity was very high in the extracts from branch of Schizandra nigra and Kadsura japonica that showed more than 90% at the concentration of 100 ${\mu}g/m{\ell}$. It also turned out that the antioxidative activity of branch of S. nigra and K. japonica was similar to ${\alpha}$-tocopherol and butylated hydroxytoluene, one of the effective synthetic antioxidants. From these results, it can be suggested that the branches of S. nigra and K. japonica have the positive antioxidative activities and can be applied for the food preservatives and cosmetic ingredient.

Stem Rot on Ligularia fischeri Caused by Sclerotium rolfsii in Korea (Sclerotium rolfsii에 의한 곰취 흰비단병)

  • Moon, Youn-Gi;Kim, Se-Won;Choi, Jun-Keun;Kwon, Soon-Bae;Shim, Hong-Sik;Ju, Ho-Jong;Choi, In-Young
    • Research in Plant Disease
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    • v.21 no.1
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    • pp.36-39
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    • 2015
  • In June 2012 and 2013, a destructive stem rot symptoms of Ligularia fischeri occurred sporadically in Hoengseong-gun and Pyeongchang-gun Gangwon-do, Korea. The typical symptom included water-soaking on the main stem, rotting, wilting and blighting, which eventually leads to death of the plant. White mycelial mats were spread over lesions and brown sclerotia were formed on stems and near soil surface. The sclerotia were white to brown, spherical or irregular, 1-3 mm in size on potato dextrose agar (PDA), The optimum temperature range of hyphal growth was $25-30^{\circ}C$ and the hyphal diameter was $4-10{\mu}m$. The typical clamp connections were observed in the hyphae of the fungus grown on PDA. The resulting sequence of 695 bp was deposited in GenBank. A BLAST search revealed that sequences of the this isolates showed >99% identity with those of Sclerotium rolfsii. On the basis of the morphological characteristics and phylogenetic analyses of molecular markers ITS rDNA, the fungi were identified as S. rolfsii. A pathogenicity test was carried out to fulfill Koch's postulates. To our knowledge, this is the first report of S. rolfsii on Ligularia fischeri in Korea.