• Korean Journal of Microbiology
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• v.24 no.2
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• pp.91-97
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• 1986

Intra and interspecfic fusants were produced by the protoplast fusion of auxotrophic mutants from Trichoderma koningii ATCC 26113 and Trichoderma reesei QM 9414. It was found that 0.6M $MgSO_4\;and\;0.6M\;NH_4Cl$ was the best osmotic stabilizer for the preparation of protoplasts from the mycelium of T. koningii and T. reesei respectively. However, $MgSO_4$ was the most suitable one for the regeneration of the protoplasts from both species. The intraspecific protoplast fusion frequencies between the auxotrophic mutants from T. reesei were $1.8{\times}10^{-2}\;to\;5.1{\times}10^{-1}$. Interspecific protoplast fusion frequencies between the auxotrophic mutants from T. koningii and T. reesei were $3.6{\times}10^{-3}$\;to\;8.4{\times}10^{-2}. Interspecific complementing fusants, however, were not alwats produced. Fusants obtained from interspecific potoplast fusion were spontaneously segregated into various strains including parental types, non-parental auxotrophic hybrids, and prototrophic hybrids on complete plate. Interspecific hybrids revealed to have partially enhanced celluloytic activities.

• Korean Journal of Microbiology
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• v.29 no.5
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• pp.314-318
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• 1991

We investigated the effect of Triton X-100 on the growth and morphology of Trichoderma koningii by comparing various parameters representing the frowth of mold in the presence or absence of Triton X-100. The specific growth rate and doubling time of T. koningii were not affected by the addition of 0.05% Triton X-100 in batch culture. However, in the presence of Triton X-100, cultures reached its stationary phase earlier and showed reduced level in total yield of biomass. The addition of Triton X-100 into solid medium also resulted in decrease in the colony radial growth rate and this response was correlated with the formation of mycelia which showed increase in branching and septation in the presence of Triton X-100.

• Korean Journal of Microbiology
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• v.27 no.2
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• pp.98-107
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• 1989

Intraspecific fusants, produced by protoplast fusion of auxotrophic mutants from Trichoderma koningii ATCC 26113, were segregated into various strains including parental types, non-parental auxotrophic hybrids, and prototrophic hybrids on complete plate. Interestingly, some of non-parental prototrophic hybrids revealed to have enhanced cellulolytic activity incomparison with other strains of parents or hybrids derived thereafter. It was also evident that prototrophic hybrids of aneuploid could be constructed after the spontaneous segregation of complementing fusants produced through the protoplast fusion.

• Korean Journal of Microbiology
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• v.36 no.1
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• pp.8-13
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• 2000

We have examined the mode of transglycosylation, catalyzed by an extracellular $\beta$-glucosidase purified from Trichoderma koningii ATCC 26113, using cellobiose, sophorose, laminaribiose and gentiobiose as substrates. The dimers separated from the reaction mixture by HPLC were analyzed by $^(1)H$-NMR spectroscopy. When cellobiose was subjected to the action of the $\beta$-glucosidase, the products included laminaribiose, sophorose and gentiobiose. When laminaribiose, sophorose or gentiobiose was used as a substrate, the $\beta$-glucosidase accumulated transglycosylation products possessing different types of $\beta$-glycosidic linkages from the original one. The amount of dimers accumulated as reaction proceeded seemed to be dependent on the velocity of hydrolysis but not on that of formation.

• Microbiology and Biotechnology Letters
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• v.18 no.6
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• pp.560-565
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• 1990

When protoplasts from auxotrophie mutant of Trkhoderma koningii CUT121(Lys-, Met-) were mixed with isolated nuclei of wild type T. koningii ATCC 261 13 and treated with PEG solution, protrophic colonies were produced with frequency of more than 30 percent. One of segregants from prototrophic colonies showed increased xylanase activity and other polysaccharide-hydrolyzing activities comparable to those of wild type strain. Through measurement of DNA contents, induced segregation, and analysis of isozyme patterns, it was revealed that the prototrophic colonies were transformants resulted from exchange of genetic materials between the two kinds of nuclei used. These results suggest that nuclei transfer technique is more efficient than conventional protoplast fusion technique for strain improvement of Trichoderma species.

• Korean Journal of Microbiology
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• v.19 no.4
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• pp.186-191
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• 1981

Protoplast production from Trichoderma koningii ATCC 26113 was investigated for the purpose of doing basic and applied researches by protoplast fusion of the cellulolytic filamentous fungus. High yields of protoplast were obtained by using the 18hr. old mycelia treated with the lytic enzyme Driselase of Kyowa Fermentation Co., Japan, in 0.6M $MgSO_4\;or\;(NH_4)_2SO_4$ as osmotic stabilizers. The optimum temeprature of mycelial digestion was about $28^{\circ}C$ and the number of protoplast increased rapidly after 3hr. digestion. Protoplasts produced at different periods showed distinct morphological heterogeneities in the whole size and the size of vacuole.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.304-308
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• 1987

The mode of transglycosylation reaction observed during the action of low-molecular-weight 1,4-$\beta$-D-glucan glucanohydrolase (EC 3.2.1.4) purified from Trichoderma koningii ATCC 26113 was investigated using $^{1}H-NMR $spectroscopy. The H-1 proton resonances were analysed. After reaction of the enzyme with cellotriose, the reaction products were separated by high performance liquid chromatography. H-1 resonances of the products were consisted with those of cellobiose, cellotriose and cellotitraose, respectively. Therefore it was proved that all the reaction products formed by the action of the enzyme on cellooligosaccharides, including transglycosylation products, possess only H-NMR -1,4-glycosidic linkage(s).

• The Korean Journal of Mycology
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• v.13 no.2
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• pp.105-109
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• 1985

Isolates of the different species groups of Trichoderma from the mushroom culture beds were identified according to Rifai's classification and influence of antibiotics produced by them against the oyster mushroom was examined. Trichoderma islolates were identified as Trichoderma hamatum, Trichoderma viride and Trichoderma koningii. Among the Trichoderma isolates, fungistatic action of Trichoderma viride was found to be most remarkable. Pleurotus ostreatus and Pleurotus sajor-caju were the most susceptable of the edible mushrooms tested, followed by Lentinus edodes, Flammulina velutipes and Auricularia auricula. A needle-shaped crystal gained from the chloroform extract of the culture filtrate of Trichoderma viride repressed distinctively the mycelial growth of the oyster mushroom. The grade of repression of the crystal at 500ppm and 1/10 aequ­ous solution of the chloroform extract against the oyster mushroom, seemed equal to that of cycloheximide at $100{\sim}200ppm$.

• Korean Journal of Microbiology
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• v.31 no.2
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• pp.157-165
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• 1993

A 1, 4-.betha.-D-xylanase, designated as xylanase II, was purified from the culture filtrate of Trichoderma koningii ATCC 251131 by column chromatography on Sephadex G-75, SP-Sephadex C-50, DEAE-Sephadex A-50 and Sephadex G-50 with an overall yield of 6.97%. It has a molecular weight of 21.000 and an isoelectric point of 9.4. The enzyme activity is optimal at pH 5.0 and at a temperature of 50.deg.C. Xylanase II is stable up to 50.deg.C, while 40 and 90% of its activity are lost after the incubation for 30 and 60 min at 60.deg.C. The enzyme degrades xylan with relatively high activity, as well as carboxymethylcellulose and Avicel. Its $K_{m}$ values for oat-spelt xylan, larchwood xylan and Avicel are 7.48, 1.98 and 13.33 mg/ml, respectively. The hydrolysis products of oat-spelt xylan by xylanase II are xylose, xylobiose, xylotriose and arabinoxylotriose, while the reaction products of larchwood xylan are xylose, xylobiose, xylotriose and small amount of higher oligomers. The action paterns of the enzyme demonstrate that xylanase II is endo-enzyme.

• The Plant Pathology Journal
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• v.20 no.4
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• pp.271-276
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• 2004

To examine the control effect of damping-off on radish caused by Pythium spp., researchers used the isolates of a fungivorous nematode, Aphelenchus avenae, and antagonistic fungi, Trichoderma spp. These were used as biocontrol agents, either alone, or in combination. Growth rates of the A. avenae isolates and fungal damages by the nematodes varied depending on Trichoderma spp., which contained lower T. koningii and T. virens cultures than other Trichoderma cultures. Phythium spp. were damaged by all five Aphelenchus isolates, but the multiplication rate of nematode isolate Aa-3 was very poor. Antibiotic activity of T. virens and T. harzianum to Pythium spp. was stronger than that of T. koningii. Control efficacy against damping-off of radish was most enhanced under the treatment using the nematode-T. harzianum combination. On the contrary, the combinations of the nematodes and T. virens or T. koningii mostly did not increase or decreased their control effect vis-$\`{a}$-vis that of the nematodes or antagonistic fungi being used alone. The results suggest that the fungivorous nematodes may play a leading role in the disease control, and that the activity of the fungivorous nematodes may be activated by T. harzianum, but inhibited by T. koningii and T.virens.