• 한국미생물·생명공학회지
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• 제25권4호
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• pp.346-353
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• 1997

During the screening of cellulase producing microorganisms, a fungal strain C-4 was selected from etiolated leaves. Based on taxonomic studies, the fungus could be classified as a strain of Trichoderma sp. When the strain C-4 was cultured in Mandels' media at 28$circ$C for 6 days, the enzyme activities detected in broth were as follows: 8.2 U/ml (28.1 U/mg) of CMCase activity, 0.75 U/ml (2.58 U/mg) of Avicelase activity, 1.67 U/ ml (5.68 U/mg) of $eta$-glucosidase activity. The optimum pH for enzyme induction was 6.2. The crude enzyme retained 100% of its original CMCase activity at 50$circ$C for 1 hr (pH 5.0), and at 4$circ$C for 24 hrs (pH 5.0). There was no effect on the CMCase activity in the presence of 1 mM of CsCl, LiCl, MgCl$_{2}$, and FeCl$_{2}$, respectively. When the crude enzyme was treated with trypsin and chymotrypsin (2% W/w) for 10 minutes, the remaining CMCase activity was 70%, but there was no further loss of activity for 60 minutes treatment at 30$circ$C. The crude enzyme showed the synergism with rumen fluid for the hydrolysis of Avicel and CMC by 118% and 130%, respectively.

• 한국버섯학회지
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• 제17권3호
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• pp.93-98
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• 2019

We investigated the correlation between density of air and the infection rate of airborne microorganisms in mushroom cultivation facilities and found that the correlation was low in places where the infection rate during cultivation was less than 1%. The farms with an infection rate of 2~5% showed a high infection rate in the inoculation room in spring and summer seasons, and in the incubation room in autumn, and the farms with an infection rate of more than 6% showed infection in all the rooms regardless of the season. The farms where the Trichoderma sp. was investigated at the time of the mushroom cultivation showed the highest infection rates of 3.17%, 2.74%, and 2.64% in summer, spring, and autumn, respectively. The farms infected with Neurospora tetrasperma showed a lesser rate of infection than the ones infected with Trichoderma sp., and the highest infection rate of 0.56% was observed in summer. Based on these results, the type of infection could be classified into five groups, where type I was farms where the infection rate is less than 1% in all seasons. Three farms belonged to this type, and the infection rate in this type was lower than that in the other types.

• 한국해양생명과학회지
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• 제7권2호
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• pp.121-128
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• 2022

L-asparaginase (ASNase) is a therapeutic enzyme used to treat acute lymphoblastic leukemia. Currently, the most widely used ASNases are originated from bacteria. However, owing to the adverse effects of bacterial ASNases, new resources for ASNase production should be explored. Fungal enzymes are considered efficient and compatible resources of natural products for diverse applications. In particular, fungal species belonging to the genus Trichoderma are well-known producers of several commercial enzymes including cellulase, chitinase, and xylanase. However, enzyme production by marine-derived Trichoderma spp. remains to be elucidated. While screening for extracellular ASNase-producing fungi from marine environments, we found four strains showing extracellular ASNase activity. Based on the morphological and phylogenetic analyses using sequences of translation elongation factor 1-alpha (tef1α), the Trichoderma isolates were identified as T. afroharzianum, T. asperellem, T. citrinoviride, and Trichoderma sp. 1. All four strains showed different ASNase activities depending on the carbon sources. T. asperellem MABIK FU00000795 showed the highest ASNase value with lactose as a carbon source. Based on our findings, we propose that marine-derived Trichoderma spp. are potential candidates for novel ASNase production.

• Mycobiology
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• 제47권3호
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• pp.280-291
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• 2019

To explore species diversity of Hypocreaceae, collections from Guangdong, Hubei, and Tibet of China were examined and two new species and a new Chinese record were discovered. Morphological characteristics and DNA sequence analyses of the ITS, LSU, $EF-1{\alpha}$, and RPB2 regions support their placements in Hypocreaceae and the establishments of the new species. Hypomyces hubeiensis sp. nov. is characterized by occurrence on fruitbody of Agaricus sp., concentric rings formed on MEA medium, verticillium-like conidiophores, subulate phialides, rod-shaped to narrowly ellipsoidal conidia, and absence of chlamydospores. Trichoderma subiculoides sp. nov. is distinguished by effuse to confluent rudimentary stromata lacking of a well-developed flank and not changing color in KOH, subcylindrical asci containing eight ascospores that disarticulate into 16 dimorphic part-ascospores, verticillium-like conidiophores, subcylindrical phialides, and subellipsoidal to rod-shaped conidia. Morphological distinctions between the new species and their close relatives are discussed. Hypomyces orthosporus is found for the first time from China.

• 한국식물병리학회지
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• 제10권4호
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• pp.325-332
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• 1994

In order to find out formulation and effect of soil amendment on Fusarium wilt of sesame caused by Fusarium oxysporum f. sp. vasinfectum, the study was conducted during the last two years of 1992 to 1993. Among 14 chemicals (1%, w/w) added to soil including CaO individually, Al2(SO4)3, Alum, and CaO suppressed mycelial growth and conidial germination of F.oxysporum f. sp. vasinfectum. CaCl2 suppressed mycelial growth only, while glycerine, KCl, K2 HPO4, and triple superphosphate suppressed conidial germination. Suppression rate was ranged from 21 to 100% on mycelial growth. The 8 chemicals were finally selected. Among the 4 organic compounds, composted pine bark showed definite suppression on mycelial growth and conidial germination of the fungus, whereas milled alfalfa leaves was only effective on conidial germination of Fusarium wilt pathogen. The antagonist Trichoderma harzianum grew well in the soil medium amended with the composted pine bark and chemicals mixture (CPM) amendment (1%, w/w) and suppressed mycelial growth of the fungus effectively. In pot test, Fusarium wilt of sesame was completely controlled by CPM amendment.

• Mycobiology
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• 제48권4호
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• pp.313-320
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• 2020

In Pleurotus sp., green mold, which is considered a major epidemic, is caused by several Trichoderma species. To develop a rapid molecular marker specific for Trichoderma spp. that potentially cause green mold, eleven Trichoderma species were collected from mushroom farms and the Korean Agricultural Culture Collection (KACC). A dominant fungal isolate from a green mold-infected substrate was identified as Trichoderma pleuroticola based on the sequences of its internal transcribed spacer (ITS) and translation elongation factor 1-α (tef1) genes. In artificial inoculation tests, all Trichoderma spp., including T. atroviride, T. cf. virens, T. citrinoviride, T. harzianum, T. koningii, T. longibrachiatum, T. pleurotum, and T. pleuroticola, showed pathogenicity to some extent, and the observed symptoms were soaked mycelia with a red-brown pigment and retarded mycelium regeneration. A molecular marker was developed for the rapid detection of wide range of Trichoderma spp. based on the DNA sequence alignment of the ITS1 and ITS2 regions of Trichoderma spp. The developed primer set detected only Trichoderma spp., and no cross reactivity with edible mushrooms was observed. The detection limits for the PCR assay of T. harzianum (KACC40558), T. pleurotum (KACC44537), and T. pleuroticola (CAF-TP3) were found to be 500, 50, and 5 fg, respectively, and the detection limit for the pathogen-to-host ratio was approximately 1:10,000 (wt/wt).

• The Plant Pathology Journal
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• 제17권6호
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• pp.365.2-365
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• 2001

• 한국미생물·생명공학회지
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• 제6권1호
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• pp.1-8
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• 1978

섬유소분해효소 생산균인 Trichoderma sp. KI 7-2의 cellulase생성을 위한 탄소원으로는 순수한 섬유소보다 볏짚 보리짚 분말을 사용하는 것이 좋았으며 1% 첨가에서 심부배양한 액을 유안농도 20~60%로 떨어뜨린 침전에서만 cellulase의 활성이 나타났다. 이 조효소의 작용최적온도는 5$0^{\circ}C$, 최적 pH는 4.2였으며, 열에 대한 안정성은 5$0^{\circ}C$에서 2시간까지 100% 활성을 유지하였고 pH에 대한 안정성은 pH4~6에서 안정하였지만 pH 4이하 및 pH 6.0 이상에서는 불안정하였다. 이러한 성질의 효소를 생산하는 균주로서 볏짚 발효시키는 몇 가지 방법을 아울러 검토하였다.

• Journal of Applied Biological Chemistry
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• 제48권1호
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• pp.7-10
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• 2005

Trichoderma sp. SY most effectively produces an extracellular ${\gamma}$-L-arabinofuranosidase (AF) using arabinose as a carbon source. AF grown on cellulose as a carbon source was purified 28-fold with 4.4% yield by DEAE exchange and HQ/20 cation exchange chromatographies The purified enzyme was found to be homogeneous on SDS-PAGE with molecular weight of 89 kDa. It exhibited a high level of activity with p-nitrophenyl ${\alpha}$-L-arabinofuranoside, showing $K_m$ and $V_{max}$ values of $0.15\;{\mu}M$ and $239.85U{\cdot}mg^{-1}$, respectively and did not require any metal ion for activity. It also released p-nitrophenol from p-nitrophenol conjugated ${\beta}$-D-xylopyranoside, and ${\beta}$-D-galactopyranoside not from ${\beta}$-D-glucopyranoside.

• Journal of the Korean Wood Science and Technology
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• 제47권2호
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• pp.210-220
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• 2019

This work aimed to evaluate the influence of culture conditions on laccase production in the co-culture of wood-rotting fungus with Trichoderma sp. The effects of infection extent, infection time, and culture filtrate of Trichoderma sp. on the laccase production by wood-rotting fungus in co-culture were examined. T. rubrum LKY-7 and T. longibrachiatum were selected as fungi which are effective in co-culture for laccase production. A significant increase in laccase activity was observed when T. rubrum LKY-7 was co-cultured with T. longibrachiatum in glucose-peptone liquid medium, yielding an increase of more than 5 times in laccase activity, as compared with control. Laccase production by T. rubrum LKY-7 during co-culturing was significantly influenced by the infection extent and the infection time of T. longibrachiatum. Maximal laccase activity was obtained when T. rubrum LKY-7 culture was infected by T. longibrachiatum after 3 days of cultivation at an inoculum size ratio of 0.5 to 1. The addition of culture filtrate or autoclaved mycelium of T. longibrachiatum to T. rubrum LKY-7 culture did not significantly enhance laccase production by T. rubrum LKY-7 as compared with control (mono cultures of T. rubrum LKY-7).