Showing papers on "Trichoderma harzianum published in 1984"

Biological control effects of a new isolate of Trichoderma harzianum on Pythium aphanidermatum

Abstract: On tente divers substrats comme milieu de base pour T. spp. Des applications generalisees et des traitements de semences sont experimentees

Evaluation of Trichoderma koningii and Trichoderma harzianum from New York soils for biological control of seed rot caused by Pythium spp..

Abstract: Isolement, caracterisation et test d'agents de lutte biologique. On recherche l'efficacite de divers materiaux adhesifs pour le traitement des semences ou comme gelifiants en semis direct fluide

Parasitism of sclerotia of Sclerotium rolfsii by trichoderma harzianum

Abstract: The ability of Trichoderma harzianum isolate 203 to attack the soil-borne plant pathogen Sclerotium rolfsii is apparently connected with the production by the isolates of chitinase and β-(1,3)-glucanase inside the attacked sclerotia during parasitism. SEM and TEM micrographs show that the mycoparasite degraded walls of sclerotial cells and the attacked cells lost their cytoplasmic contents. It is assumed that T. harzianum utilizes sclerotial cell contents thus enabling it to sporulate intensively on the sclerotial surface and inside the digested cells.

Associative cellulolysis and dinitrogen fixation by co-cultures of Trichoderma harzianum and Clostridium butyricum

Abstract: Lignocelluloses are a major source of carbon into ecosystems and represent the principal constituent of agricultural, forestry and municipal wastes. The large proportion of cellulose and hemicellulose in these wastes leads to a high C:N ratio which often results in N limitation during decomposition. This could be overcome if the decomposer organisms combined both the cellulolytic (cellulase) and N2-fixing (nitrogenase) functions. With the exception of bacteria isolated from the specialized environment of marine shipworms1,2, no organism possessing both cellulase and nitrogenase has yet been isolated from nature or genetically engineered. We now report the cooperative degradation of cellulose in which the fungus Trichoderma harzianum provides the cellulase function and an obligately anaerobic bacterium, Clostridium butyricum, provides the nitrogenase function. These co-cultures utilized cellulose as the sole carbon source for N2 fixation, resulting in a substantial increase in the rate of substrate decomposition compared with the fungus alone. The co-cultures developed in apparently aerobic environments, demonstrating that aerobes and anaerobes can co-exist, the aerobe presumably providing respiratory protection to the anaerobe.

Novel isolate of trichoderma, fungicidal compositions containing said isolate and use thereof

Abstract: A biological control agent comprising the mycoparasite Trichoderma harzianum T-315 (ATCC No. 20671), which is characterized by fungicidal activity against fungi of the genera Pythium, Rhizoctonia, Sclerotium and Fusarium. This strain is useful for controlling damping-off, root-rot, crown-rot and neck-rot in seedling crops. This strain is also resistant to chemical pesticides and soil-sterilants and useful for integrated biological and chemical control of soil-borne pathogens.

Control of white rot of garlic by antagonistic fungi under controlled environmental conditions

Abstract: Several fungi were isolated from soil samples collected in areas with a high incidence of white rot disease of garlic at Amarantina county, Minas Gerais, Brazil. After the screening in vitro for antagonists to Sclerotium cepivorum, three fungi were found to be highly inhibitory to the pathogen. These fungi were identified as Trichoderma harzianum Rifai, Paecilomyces lilacinus (Thom.) Samson, and a Penicillium sp. The three antagonists produced in vitro nonvolatile antibiotics towards Sc. cepivorum. These substances were thermolabile (120 °C, 15 min) and significantly inhibited the growth of Sc. cepivorum. Interactions between the pathogen and each antagonist, studied by a dual slide-mount technique, showed that Pa. lilacinus and Penicillium sp. caused an inhibition halo to Sc. cepivorum although hyphal contact never occurred. Trichoderma harzianum showed inhibitory activity at a distance, and after contact with Sc. cepivorum, caused hyphal cytoplasm disintegration and cell wall collapse. This detrimental ...

Interactions between Sclerotium rolfsii and Trichoderma spp: Relationship between antagonism and disease control

Abstract: Ten isolates of Trichoderma spp were examined for their ability to antagonize growth and to parasitize mycelium of Sclerotium rolfsii (Sr-1) on agar media, to inhibit germination of sclerotia of S. rolfsii on natural soil plates and to sporulate on the sclerotia, and to protect bean seedlings against the pathogen in the greenhouse. A high negative correlation ( r = −0.844) was observed between plant stand in the greenhouse and sclerotial germination on soil plates but not with antagonism on agar plates. Three isolates of T. harzianum (Th-7, Th-20, WT-6) and one of T. hamatum (TRI-4) were especially effective in reducing sclerotial germination and controlling disease in the greenhouse. Three isolates of Trichoderma spp (WT-6, TMP, and TRI-4), effective in reducing sclerotial germination of isolate Sr-1, also prevented sclerotial germination in four out of five additional S. rolfsii isolates studied.

Antifungal compositions containing trichoderma active against fusarium

Abstract: A biological control agent comprising the antifungal agent Trichoderma harzianum T-35 (ATCC No. 20691), which is characterized by antifungal activity against fungi of the genus Fusarium. This strain is useful for protecting most crops affected by the fungus Fusarium spp. and is more active than other previously disclosed strains. Biocontrol compositions containing T. harzianum T-35 (ATCC No. 20691) provide antifungal protection to a broad spectrum of plants, including wheat, cotton, melons and tomatoes.

The Quest for Trichoderma Cryptochrome

Abstract: The common soil fungus Trichoderma harzianum Rifai, (previous designation, Trichoderma viride Pers. ex Fries, ATCC 32173) grows as a vegetative mycelium in the dark, provided the nutrient supply is sufficient. A short pulse of blue light induces a local switch to sporulative development of asexual conidia. The conidiophores develop in a ring located where the perimeter of the colony had been when it received light [8]. The action spectrum for photoconidiation has maxima at 365, 430, 455, and 480 nm [9]. These peaks correspond to those of cryptochrome, a pigment(s) which, so far, has been identified as a working hypothesis but not as a molecule [7]. Kumagai and Oda [15] extended the action spectrum to the UV and found an additional peak at 310 nm which may not be present in all organisms having cryptochrome responses.

Production and regulation of cellulases in Trichoderma harzianum

Abstract: The highest production of extracellular cellulases (Filter paper activity, Carboxymethyl cellulase and β-glucosidase) by Trichoderma harzianum was achieved on delignified wheat straw. Glycerol at a concentration of one per cent strongly repressed the formation of all the cellulolytic components. Addition of cyclic AMP did not relieve the repression caused by glycerol but lowered the level of existing cellulase enzymes.

Biological Control of Seed Rot and Preemergence Damping-Off of Chickpea withPenicillium oxalicum

Abstract: On etudie les agents biologiques aptes a lutter contre la pourriture des graines a Pythium et la fonte des semis du pois chiche par traitement des semences avec des conidies de P.o, Trichoderma hamatum, T. harzianum, on verifie si l'enrobage des semences avec les conidies de ces champignons a un effet phytotoxique, on experimente au champ l'efficacite des traitements pour des semences traitees conservees pendant 8 mois a 4°C

Strain of Trichoderma harzianum, process for its isolation, process for its culture, peptides or compounds produced by this strain and application of this strain and these peptides or the product produced by the culture process as a means for biological control in the form of a phytosanitary product

Abstract: This new strain is deposited at the Pasteur Institute under No. 1223 and at the ATCC under No. 20672. It has been isolated by a cloning technique from Trichoderma harzianum fungi from a moist soil such as a market gardening soil or a cultivated soil. This new strain and the peptides which it produces, called Trichorzianines are employed as a means of biological control in particular for the treatment of the grey rot of vines or the silver leaf disease of fruit trees.

Effect of inoculum density, nitrogen source and saprophytic fungi on Fusarium wilt of Mexican lime

Abstract: Mexican lime seedlings were inoculated with 0, 500, 1000, 2000, 4000 and 8000 microconidia ofFusarium oxysporum f. sp.citri per gram of potting media. The percent infection and mean disease severity rating increased with increasing inoculum density of the pathogen. In potting mix infested withAspergillus ochraceus, Penicillium funiculosum andTrichoderma harzianum at 5000 conidia per gram 2 weeks prior to infestation withF. oxysporum f. sp.citri at 0, 1000, 4000, and 8000 microconidia per gram,A. ochraceus reduced,P. funiculosum increased andT. harzianum had no effect on disease severity or pathogen population. OnlyP. funiculosum showed antagonistic activityin vitro against the pathogen. Disease severity and pathogen propagule densitites were greater and pH was lower in potting media fertilized with NH4−N than in media fertilized with NO3−N.

Cellulolytic enzymes of fungi isolated from wood materials

Abstract: Species of Cunninghamella, Gliocladium deliquescens, Trichoderma harzianum and T. koningii were isolated from rotten wood chips. When grown on medium containing cellulose, all except Cunninghamella produced the three primary enzymes (exoglucanase, endoglucanase and β-glucosidase) of the cellulase complex. The patterns for enzyme production, changes in mycelial mass and pH of the induction medium for T. harzianum and T. koningii were closely similar, and were distinguishable from those of G. deliquescens.

Production and localization of β-glucosidase in Trichoderma harzianum and some aspects of catabolite repression

Abstract: Maximum production of aryl-β-glucosidase by Trichoderma harzianum was obtained in Vogel's medium supplemented with cellobiose as the carbon source at pH 5.0 under stationary culture conditions at 27 °C. In the exponential phase the bulk of the enzyme was almost equally distributed in the extracellular and cell debris fractions and a negligible amount was present in the cytosol. However, in the late stationary phase, extracellular β-glucosidase increased to 80% of the total enzyme. When cellulosic substrates were used, a major portion of the enzyme (90%) appeared in the extracellular fraction at all stages of growth. The repression of extracellular enzyme in the presence of exogenous glucose in the medium was apparent and the synthesis and release of enzyme were resumed after its depletion. The glucose effect in essence may be related to the adverse effect of low pH on the integrity of the enzyme.

Straw decomposition process

Abstract: The invention relates to decomposing straw and is con­ cerned particularly with the problem of increasing the nit­ rogen content of decomposed straw by inoculation of the straw with a dinitrogen-fixing anaerobe, e.g. Clostridium butyricum. It has been found that the nitrogen content of the straw can be increased by co-inoculating the straw with a cellulolytic fungus which releases the cellulase enzyme extracellularly, so that it diffuses through the straw, and which satisfies certain defined requirements. A Trichoderma harzianum or T. hamatum or Sordaria alcina is preferred as the cellulolytic fungus. The third inoculant consumes oxygen, and forms a polysaccharide protective coat around the anaerobe, and is preferably an Enterobacter. A novel strain of Enterobacter cloacae excellent for this purpose has been deposited as NCIB 11836, and this strain and appropriate mutants and variants thereof are within the invention.

INTERACCION DE TRATAMIENTO BIOLOGICO Y QUIMICO EN EL COMBATE DEL OJO DE GALLO (Mycena citricolor) EN EL CAFETO. 1

Abstract: Interaction of biological and chemical treatment in the control of "ojo de gallo" disease (Mycena citricolor) in coffee. By means of field tests it was detennined that coffee grindings infested with the fungus Trichoderma harzianum were effective in controlling "ojo de gallo" (Mycena citricolor) when dusted upon infected coffee leaves at the beginning of the rainy season. The fungicide copper oxichloride 88 P.M. (Cobox) was not effective in the control of the disease, but aided in the biological control when both grindings and fungicide were used together. In those treatments where Trichoderma was used, reduction in the number of lesions with "cabecitas" (gemmae), and total number of "cabecitas" per branch, reached percentages of 80.2 and 88.7, respectively. Mean Trichoderma lesion colonization percentage was 67.

Efficacy of Trichoderma harzianum as a Biocontrol Agent forRhizoctonia solani, the lncitant of Collar-rot of Coffee Seedlings

Abstract: The effectiveness of an antagonistic isolate, Trichoderma harzianum Rifai for controlling collar rot of coffee seedlings was assessed. Under field conditions using natural inoculum of Rhizoctonia solani Kuhn. and under artificially infested soils, seed treatment with T. harzianMm brought down the incidence of collar-rot disease. A soil incorporation method of inoculum was superior to the seed treatment. The possibility of using T. harzianum as a. biocontrol agent against collar-rot of coffee is discussed.

New strain of trichoderma haldiana, isolation thereof, culture method thereof, new peptide or compound produced therefrom and use of said strain and new peptide or product obtained by said culture method in form of plant disease exterminating preparation as biologically effective means

Abstract: This new strain is deposited at the Pasteur Institute under No. 1223 and at the ATCC under No. 20672. It has been isolated by a cloning technique from Trichoderma harzianum fungi from a moist soil such as a market gardening soil or a cultivated soil. This new strain and the peptides which it produces, called Trichorzianines are employed as a means of biological control in particular for the treatment of the grey rot of vines or the silver leaf disease of fruit trees.

Apple Fruit Rot Caused by Trichoderma harzianum

Abstract: intact plants was investigated by inoculating 36-day-old Yandee lupins in a mist chamber, and spraying with 1% vlv Spray,Seed® at 10, 20, 30 and 40 days after inoculation. Stromata of P, leptostromiformis became visible on stems and petioles 7-10 days after herbicide treatment. The most extensive stromatal development occurred with herbicide application 20 or 30 days foilowing inoculation, The method was also tested in the field during winter 1983 with the cultivar Yandee, Infected lupin stubble was spread over alternating field plots leaving a stubble-free plot between each treated plot. Plants were seiected at random in each plot and sprayed with 1% vlv Spray.Seed®, Fifteen days after herbicide treatment on June 21, every plant in the stubble-treated plots (34/34) displayed signs of P, teptostromitormis, compared with only 4/30 plants in the stubble-free areas, The paraquat-dlquat test overcomes the problems caused by the lack of symptoms of P. leptostromitormis infection in green lupin plants (2), and the low frequency of isolation of the fungus from symptomless infected green stems. It will be exploited in studies of the epidemiology of Phomopsis stem blight in Western Australia. and in the development of glasshouse screening tests for disease resistance. Appiication of the herbicide after a suitable incubation period should facilitate rapid progress in breeding lupin varieties resistant to the disease. The authors thank Mr F. O'Donnell for valuable glasshouse and fieid assistance.

Enzymatic hydrolysis and fermentation of agricultural residues to ethanol

Abstract: A combined enzymatic hydrolysis and fermentation process was used to convert steam-treated wheat and barley straw to ethanol. Maximum conversion efficiencies were obtained when the substrates were steamed for 90 s. These substrates could yield over 0.4 g ethanol/g cellulose following a combined enzymatic hydrolysis and fermentation process procedure using culture filtrates derived from Trichoderma harzianum E58. When culture filtrates from Trichoderma reesei C30 and T. reesei QM9414 were used, the ethanol yields obtained were 0.32 and 0.12 g ethanol/g cellulose utilized, respectively. The lower ethanol yields obtained with these strains were attributed to the lower amounts of ..beta..-glucosidase detected in the T. reesei culture filtrates.