• Mycobiology
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• v.31 no.3
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• pp.139-144
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• 2003

This study was conducted to investigate physiological characteristics of Trichoderma spp. isolated from Pleurotus spp. Damage tests of Pleurotus spp. and mycotoxins tests of Trichoderma spp. were also done. The optimal growth temperature of Trichoderma spp. was $27{\sim}30^{\circ}C$. Although, T. longibrachiatum was able to grow at $37^{\circ}C$ and grew $30{\sim}40$ times faster than Pleurotus. The colony colour on PDA medium of T. cf. virens was yellowish green, T. longibrachiatum was yellow, and T. harzianum was turning to bright green. In damage tests of Pleurotus by Trichoderma, T. cf. virens caused the most severe damage to Pleurotus. T. longibrachiatum and T. harzianum caused less damage on Pleurotus but were able to cause greater damage to P. eryngii. One of the mushroom cultivars, P. ostreatus 8 was the most resistant to all Trichoderma spp.. Chitinolytic mycotoxin released by Trichoderma spp. caused 52.7% damage to Pleurotus. Mycotoxins released by T. longibrachiatum caused the greatest damaged(78.6%) on P. eryngii.

• Korean Journal of Microbiology
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• v.22 no.3
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• pp.157-165
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• 1984

Seasonal and spatial variations in propagule numbers of Trichoderma species were investigated every other month for one year in deciduous and coniferous forest soils and evaluated the relationships of Trichoderma spp. populations to soil environmental factors. The total population of Trichoderma spp. increased until summer and then declined until winter. The yearly mean frequency of Trichoderma spp. exceeded 1.4% of total fungal propagules in two sites. Decreases of absolute an relative propagule numbers of Trichoderma spp. with increasing soil depth were found and variation in Trichoderma spp. propagules caused by differences in soil depth ($0{\sim}50cm$) was greater than that caused by differences in sampling time. The most common species occurring in two sites was T. viride, followed by T. polysporum, T. koningii, and T. hamatum. Individual species of Trichoderma showed diferent abundance trend in accordance with sampling time. T. viride was dorminant from spring to autumn, while T. polysporum dominated over the other speicies in winter. Variations in propagule number of Trichoderma sppp. were principally mediated by the actions of biotic environmental factors rather than by the direct effects of abiotic factors. In multiple-regression analyses, 48% of the total vaiation in Trichoderma spp. propagules in deciduous site could be accounted for by total fungal propagules and soil CMCase actvity. In coniferous site, 65% of total variation could be accounted for by total fungal and bacterial propagules, moisture content and organic carbon content.

• Mycobiology
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• v.29 no.1
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• pp.54-57
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• 2001

Field studies were conducted over two seasons during the summers of 1997 and 1998 to investigate the effects of different spatial arrangements(random or highly aggregated) of sclerotia of Sclerotinia sclerotiorum and alginate pellet types(bran or polyethylene glycol) on colonization of sclerotia by Trichoderma spp. Treatment with alginate pellets increased the mean percentages of sclerotia colonized by Trichoderma spp. in both years. Distribution patterns of sclerotia affected the mean percentage of sclerotia colonized by Trichoderma spp. in both years, indicating that a highly aggregated distribution of sclerotia was more favorable to colonization by Trichoderma spp. The effects of the different pellet types(bran or PEG) were not siginificant in both years(P>0.05). The application of higher densities(200 pellets per 1 $m^2$) of alginate pellets resulted in higher mean percentages of sclerotia colonized by Trichoderma spp. in 1998(P<0.05), but did not in 1997.

• Mycobiology
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• v.31 no.2
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• pp.74-80
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• 2003

Isolates of Trichoderma spp. collected from Pleurotus ostreatus and P. eryngii beds, which included loosened substrate compactness and development of green colour, were grouped into three species. The occurrence of different species of Trichoderma was as T. cf. virens(70.8%), T. longibrachiatum(16.7%) and T. harzianum(12.5%). The conidia of Trichoderma spp. were ellipsoidal, obovoid and phialides were bowling pins, lageniform and the length of phialides was $3.5{\sim}10.0{\times}1.3{\sim}3.3{\mu}m$. Phialides of T. cf. virens and T. harzianum were tending clustered, but it was solitary disposition in T. longibrachiatum. T. cf. virens was characterized by predominantly effuse conidiation, sparingly branched, and fertile to the apex and it was penicillate type. RAPD analysis could detect variability amongst three different species of Trichoderma using two newly designed URP-primers. However, intra-specific variation could not be detected in all the isolates except for rDNA sequence data classified Trichoderma isolates into three distinct groups representing three species. The profiles of rDNA sequences of isolates representing a species showed high similarity in T. cf. virens and T. harzianum. However, there was a variation in rDNA sequences of isolates representing T. longibrachiatum. The results of present study reveals that molecular techniques of RAPD and rDNA sequencing can greatly aid in classification based on morphology and precise identification of fast evolving species of Trichoderma.

• Mycobiology
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• v.48 no.4
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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).

• Journal of Life Science
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• v.13 no.3
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• pp.355-358
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• 2003

Various Trichoderma spp. were evaluated for the development of biofungicides to control soilborne pathogen, Rhiztonia solani, Various Trichoderma spp. were initially tested for their ability to inhibit growth of R. solani by inhibition zone test. Inhibition zones of 3∼5 mm toward R. solani were detected on PDA agar plates. The parasitic activity of strains, the activities of cell-wall-degrading enzymes such as glucanases and chitinases, were also evaluated. Highest activities of glucanase and chitinase were 3.5 U/ml and 0.9 U/ml, respectively, Isolated Trichoderma spp. also exhibited good growth with currently used agrochemicals, which represents that the isolated biofungicides can be mutually used with agrochemicals.

• The Korean Journal of Mycology
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• v.20 no.4
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• pp.337-346
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• 1992

Trichoderma spp. are an effective control agent for damping-off or other plant diseases. The interaction between. T. hamatum and Rhizoctonia solani on the rhizosphere or surface soil were examined to assess the possible roles of antibiosis or competition in the mechanisms of biological control agents as a basic research. In a proportional comparison, total bacteria, fungi, actinomycetes and Trichoderma spp were 65%, 8.8%, 25.9% and 0.28% respectively in their distribution in the soil. Among Trichoderma spp isolated, the 5 species of Trichoderma spp were indentified as T. koninggii, T. pseudokoninggii, T. aureoviridi, T. hamatum and T. viride respectively. In a mycoparasitic test, one isolate of T. hamatum strain Tr-5 showed an enzymatic ability to break fungal hyphae into piecies and infected on the R. solani hyphae showing a parasitism. Spore germination of the all isolates of Trichoderma spp showed a 1.7-7.3% of germination in natural soil conditions, but the percentage was high in sterile soil indicating all the natural soil were fungistatic on conidia of Trichoderma spp. In rhizosphere competent assay in pea plant, the antagonistic T. hamatum, T. viride, T. koninggii, T. pseudokoninggii showed a colonizing upper soil depth in rhizosphere around 1-3 cm in root zone, but the colonizing ability was much reduced along the deeper the soil depth. Propagule density was decreased in deeper the soil layer. Disease development rate treated alone with plant pathogens, Fusarium solani, Rhizoctonia solani, Cylindrocarpon destructans increased, but disease incidence rate reduced in treatment with combinations with antagonistic T. hamatum strain Tr-5.

• Journal of Mushroom
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• v.2 no.4
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• pp.184-191
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• 2004

Mutual growth limitation was observation when the two antagonistic fungi was come in contact with each other. Brown line was formed 2day after contact with Trichoderma spp., and then, green spores formed overnight. The laccase activity of L. edodes was stimulated when this fungus wsa co-incubated with Trichoderma spp. for a few days in liquid media. In sawdust-rice bran nixtures, outstanding broun line developed when the two antagonistic fungi co-cultured. The pH of the substrates changed from 5.5 to 4.5 after overgrowth, suggesting a difference in the degradation ability and the preference of the two fungi for the lignocellulose material.

• Mycobiology
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• v.36 no.4
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• pp.270-273
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• 2008

Trichoderma spp. cause large crop losses of the cultivated shiitake mushroom, Lentinula edodes. We bred several shiitake strains that are resistant to Trichoderma spp. using di-mon mating to establish a useful method for controlling the greenmold disease. We examined the competitive ability of L. edodes against Trichoderma spp. using a dual culture system to select resistant strains. By screening Trichoderma-resistant strains, we found that among 11 parental strains, 4 strains, including KFRI 36, were confirmed resistant strains. They showed especially strong resistance to T. harzianum, which formed deadlock after mycelial contact and then invaded into the territory of T. harzianum. KFRI 171 also showed resistance to T. atroviride strains. Among 13 strains, which were made by hybridization of shiitake strains, 5 were confirmed to be resistant to Trichoderma, including KFRI 58-1. Their resistance was not correlated to the resistant activity of their parents’ strains. Two strains lose resistance and two strains acquire resistance compared to their parents’ strains. In SEM observation, the mycelium of L. edodes at the interaction zone of Lentinula-Trichoderma was rugged and swollen by T. harzianum.

• Journal of Marine Life Science
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• v.7 no.2
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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.