Showing papers on "Trichoderma harzianum published in 1992"
TL;DR: Three proteins which display chitinase activity were purified from the supernatants of Trichoderma harzianum CECT 2413 grown in minimal medium supplemented with Chitin as the sole carbon source, suggesting that each protein is encoded by a different gene.
Abstract: Three proteins which display chitinase activity were purified from the supernatants of Trichoderma harzianum CECT 2413 grown in minimal medium supplemented with chitin as the sole carbon source. Purification was carried out after protein precipitation with ammonium sulphate, adsorption to colloidal chitin and digestion, and, finally, chromatofocusing. By this procedure, two chitinases of 42 kDa (CHIT42) and 37 kDa (CHIT37) were purified to homogeneity, as judged by SDS/PAGE and gel filtration, whereas a third, of 33 kDa (CHIT33), was highly purified. The isoelectric points for CHIT42, CHIT37 and CHIT33 were 6.2, 4.6 and 7.8, respectively. The three enzymes displayed endochitinase activities and showed different kinetic properties. CHIT33 was able to hydrolyze chitin oligomers of a polymerization degree higher than n= 4, its Km for colloidal chitin being 0.3 mg/ml. CHIT42 and CHIT37 were able to hydrolyze chitin oligomers with a minimal polymerization degree of n= 3, their Km values for colloidal chitin being 1.0 mg/ml and 0.5 mg/ml respectively. With regard to their lytic activity with purified cell walls of the phytopathogenic fungus Botrytis cinerea, a hydrolytic action was observed only when CHIT42 was present. Antibodies against CHIT42 and CHIT37 specifically recognized the proteins and did not display cross-reaction, suggesting that each protein is encoded by a different gene.
265 citations
TL;DR: The fungus Trichoderma harzianum, applied to pathogen-free soil, induced an increase in emergence of seedlings, plant height, leaf area and dry weight and was found in roots of plants growing in soil treated with the fungus.
Abstract: The fungus Trichoderma harzianum which was applied to pathogen-free soil, induced an increase in emergence of seedlings, plant height, leaf area and dry weight. The fungus was applied to the soil by three different methods: conidial suspension, wheat-bran/peat preparation and seed coating. The most prominent effect was observed in the wheat-bran/peat preparation. Responses occurred in different plant growth substrates such as sandy loam soil, autoclaved soil, vermiculite, peat and a mixture of vermiculite and peat (1:1, v/v). T. harzianum was also found in roots of plants growing in soil treated with the fungus.
260 citations
TL;DR: Chitinase (EC 3.2.1.14), from the culture filtrate of Trichoderma harzianum, was successively purified by precipitation with ammonium sulfate followed by ion-exchange chromatography on Q-Sepharose, gel filtration on Sephadex G-100, and hydrophobic interaction on Phenyl- Sepharose CL-4B.
116 citations
TL;DR: Direct, analytical evidence that Azospirillum brasilense produces gibberellin (GA) in the presence of complex biochemicals and another microorganism is found.
Abstract: Rhizobacteria have been shown to produce gibberellin (GA)-like substances, but this evidence has been obtained primarily from analysis by bioassay, usually on chemically-defined medium, and always in systems containing a single microorganism. We examined, by capillary gas chromatography-mass spectrometry, the production of GAs by Azospirillum brasilense (1) in pure culture on chemically-defined medium and (2) in co-culture with Trichoderma harzianum, a fungus which degrades cellulose and controls some bacterial and fungal phytopathogens, in a barley straw decomposition culture. Pure cultures of Azospirillum brasilense contained Ga3 >iso-Ga3 >GA1, but no precursors thereto were detected. In the Azospirillum + Trichoderma straw culture 0.5 ng Ga1 g−1 straw was measured. This is direct, analytical evidence that Azospirillum brasilense produces GA in the presence of complex biochemicals and another microorganism.
106 citations
TL;DR: When the mycoparasitic, biocontrol fungus Trichoderma harzianum was allowed to grow on nylon fibers treated with concanavalin A or Sclerotium rolfsii lectin, it coiled around the nylon fibers and produced hooks in a pattern similar to that observed with the real host hyphae.
Abstract: When the mycoparasitic, biocontrol fungus Trichoderma harzianum was allowed to grow on nylon fibers treated with concanavalin A or Sclerotium rolfsii lectin, it coiled around the nylon fibers and produced hooks in a pattern similar to that observed with the real host hyphae. The incidence of interaction between T. harzianum and S. rolfsii lectin-treated fibers was significantly higher than that of the controls (untreated or blocked activated fibers). These findings provide direct evidence for the role of lectins in mycoparasitism.
78 citations
TL;DR: Six saprophytic fungi belonging to different genera and isolated from three organic substrates were tested under controlled in vitro conditions for their effect on the germination of Glomus mosseae and the development of vesicular-arbuscular mycorrhizal fungal (VAMF) mycelium.
Abstract: Six saprophytic fungi belonging to different genera and isolated from three organic substrates were tested under controlled in vitro conditions for their effect on the germination of Glomus mosseae (Nicol & Gerd) Gerd & Trappe resting spores and on the development of vesicular-arbuscular mycorrhizal fungal (VAMF) mycelium The development of G mosseae was stimulated by sterile water extracts from organic substrates and by the presence of Trichoderma spp isolated from these substrates Microbial inoculation did not affect the percentage of spore germination, which reached 90–95% after 26 days' incubation, but the germination rate was hastened and the development of VAM mycelium from germinated spores was enhanced by the presence of Trichoderma spp Stimulation caused by Trichoderma might be attributed to the production of volatile compounds more than to non-volatile compounds released to the growing media No hyphal contact between both types of fungi was necessary to detect stimulation in dual inoculation treatments The other saprophytes tested inhibited spore germination
76 citations
TL;DR: It is shown that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation.
Abstract: Two filamentous fungi, the white-rot fungus Trametes versicolor and the soil fungus and potential biocontrol organismTrichoderma harzianum, have been grown in pure and mixed cultures on low-N (0.4 mM) and high-N (4 mM) defined synthetic media to determine the activities of selected wood-degrading enzymes such as cellobiase, cellulase, laccase,and peroxidases. Growth characteristics and enzyme activities were examined for potential correlations. Such correlations would allow the use of simple enzyme assays for measuring biomass development and would facilitate predictions about competitiveness of species in mixed fungal cultures. Our results show that while laccase and Poly Red-478 peroxidase activities indicate survival of the decay fungus, none of the monitored extracellular enzymes can serve as a quantitative indicator for biomass accumulation. As expected, the level of available nitrogen affected the production of the enzymes monitored: in low-N media, specific cellobiase, specific cellulase, and perox...
58 citations
TL;DR: One of the substances secreted by Trichoderma harzianum secretes substances into the growth medium which inhibit the growth of microorganisms was identified as 3-(2-hydroxypropyl)-4-hexadienyl)-2(5H)-furanone, a new natural product.
52 citations
TL;DR: In the presence of these biocontrol agents, mycorrhiza formation with Glomus mosseae was significantly depressed, particularly with S. griseoviridis, and Infection by the root pathogen Rhizoctonia solani was not altered by these agents.
Abstract: A container system for rapid infection of roots with pathogenic or mycorrhizal fungi was used to test the effect of the two commercial biological control agents, Trichoderma harzianum and Streptomyces griseoviridis, on the formation of vesicular-arbuscular mycorrhiza in soybean. In the presence of these biocontrol agents, mycorrhiza formation with Glomus mosseae was significantly depressed, particularly with S. griseoviridis. Infection by the root pathogen Rhizoctonia solani was not altered by these agents. Remarkably, not only R. solani but also T. harzianum induced accumulation of large amounts of the phytoalexin glyceollin in the roots. In contrast, roots inoculated with S. griseoviridis or with the mycorrhizal fungus G. mosseae did not accumulate glyceollin.
52 citations
TL;DR: Harziandione represents a new class of diterpenes and is the first diterpene isolated from Trichoderma species and the structure and relative stereochemistry were determined from an X-ray diffraction study.
Abstract: The isolation and structural elucidation of harziandione [2] from the biological control agent Trichoderma harzianum is described. Harziandione represents a new class of diterpenes and is the first diterpene isolated from Trichoderma species. The structure and relative stereochemistry were determined from an X-ray diffraction study
51 citations
TL;DR: ‘Chickpea wilt complex’, an important disease of chickpea, was effectively controlled by a biological agent Trichoderma harzianum and its integration with fungicides and significantly reduced the incidence and increased crop yield.
Abstract: ‘Chickpea wilt complex’, an important disease of chickpea, was effectively controlled by a biological agent Trichoderma harzianum and its integration with fungicides. Evaluation of wheat bran sawdust medium for T. harzianum showed high potentiality. Soil application with different doses of T. harzianum gave 53–50–85.70% disease control in the glasshouse, increasing with the amount of T. harzianum applied. In the field integration of T. harzianum with different fungicides significantly reduced the incidence of ‘chickpea wilt complex’ and increased crop yield. Seeds treated with Vitavax‐200 and Ziram resulted in 29.9% disease control, which was further increased to 63.3% when integrated with soil application of T. harzianum.
Journal Article•
TL;DR: Twenty species of fungi isolated from root and soil samples collected in 50 localities in Brazil were tested on agar as potential biological control agents against second-stage juveniles (J2), eggs, and egg masses of Meloidogyne incognita race 3 to show substantial variability in virulence among isolates of the same species.
Abstract: Twenty species of fungi isolated from root and soil samples collected in 50 localities in Brazil were tested on agar as potential biological control agents against second-stage juveniles (J2), eggs, and egg masses of Meloidogyne incognita race 3. In vitro tests with eggs and egg masses showed isolates of Paecilomyces lilacinus, Arthrobotrys conoides, A. musiformis, A. robusta, Monacrosporium ellisosporum, Dactylaria thaumasia, Cylindrocarpon sp., and Trichoderma harzianum to be efficient parasites. Substantial variability in virulence among isolates of the same species was observed. Juveniles were parasitized by nematode-trapping fungi but not by opportunistic or ectoparasitic fungi. The more promising isolates of M. ellipsosporum, P lilacinus, F. oxysporum, T. harzianum, A. robusta, and D. thaumasia were further evaluated against M. incognita race 3 in greenhouse pots. Each fungus and the nematode, alone or in combination, were mixed into soil that either had been fumigated or had n
TL;DR: The most suitable conditions for protoplasting were as follows: age of the organism in slant, 3 days; mycelium age, 20 h; volume of lytic enzymes, 190 ml;Mycelial weight (dry equivalent), 1.66 g; time of contact with lytic enzyme, 2 h; temperature of protoplasts, 30°C; phosphate buffer, 25 m m , pH 6.5; KCl as osmotic stabilizer, 0.7 m
TL;DR: Introduction of the Neurospora crassa ben gene, coding for a benomyl-resistant β-tubulin, into a T. reesei by transformation yielded a series of transformants, which exhibited increased growth, increased cellulase formation, and highly branched, crippled morphology.
Abstract: To investigate the possible relationship between resistance to benomyl and the production of cellulases by Trichoderma spp., we investigated the effect of benomyl on growth and cellulase formation in Trichoderma reesei, Trichoderma harzianum, and the benomyl-resistant mutant T. harzianum T95. While T. reesei produced the highest and T. harzianum the lowest cellulase amounts, growth of both strains was equally inhibited by 2 μg/mL benomyl. However, sublethal doses of benomyl (0.2–0.5 μg/mL) promoted growth, stimulated cellulase production, and produced a highly branched, crippled morphology. The same phenomenon was observed with T. harzianum T-95, albeit at higher (5–10 μg/mL) benomyl concentrations. Introduction of the Neurospora crassa ben gene, coding for a benomyl-resistant β-tubulin, into a T. reesei by transformation yielded a series of transformants, which exhibited increased growth, increased cellulase formation, and highly branched, crippled morphology. Key words: Trichoderma harzianum, Trichoderm...
TL;DR: Trichoderma harzianum was more effective in colonizing the substrate and in reducing the incidence of pathogens in wheat than in black oat, but it had no effect on decomposition of either type of residue, as determined by dry weight loss at the end of the experiment.
Abstract: Inoculation of wheat and black oat straw with Trichoderma harzianum resulted in a reduction in the incidence of Cochliobolus sativus (wheat only), Fusarium graminearum and other Fusarium spp. The Trichoderma treatment had no effect on the isolation of Pyrenophora avenae from black oat residues. Trichoderma harzianum was more effective in colonizing the substrate and in reducing the incidence of pathogens in wheat than in black oat, but it had no effect on decomposition of either type of residue, as determined by dry weight loss at the end of the experiment.
TL;DR: It was proved that the beta (1-5)-linked galactofuranosyl residues only are responsible for the antigenicity of the extracellular polysaccharides of Penicillium and Aspergillus molds.
Abstract: To study the structures of the epitopes of the extracellular polysaccharides from Penicillium and Aspergillus species, an exo-beta-D-galactofuranosidase was purified from a commercial crude enzyme preparation from Trichoderma harzianum. Analysis of ring size and linkage position of the galactose residues of the extracellular polysaccharide of Penicillium digitatum, before and after enzymatic treatment, was determined by the reductive-cleavage technique. In addition to terminal and beta (1-5)-linked galactofuranosides, beta (1-6)-linked and beta (1,5,6)-linked branched galactofuranose residues could be identified. After degradation with the purified exo-beta-D-galactofuranosidase, all initial linkages of the galactofuranose residues were still present, but the amount of beta (1-5)-linked galactofuranose residues had decreased considerably. Treatment of the extracellular polysaccharides of Penicillium and Aspergillus species with the purified exo-beta-D-galactofuranosidase resulted in complete disappearance of the enzyme-linked immunosorbent assay reactivity of these polysaccharides, using immunoglobulin G antibodies raised against P. digitatum. Therefore, with the use of this enzyme, it was proved that the beta (1-5)-linked galactofuranosyl residues only are responsible for the antigenicity of the extracellular polysaccharides of Penicillium and Aspergillus molds. A new structural model for the antigenic galactofuranose side chains of the galactomannan from P. digitatum is proposed.
TL;DR: Limited growth seems to favour the production of this lactone in Trichoderma harzianum, and an increase in 6-pentyl-α-pyrone production was observed in comparison with the media containing methyl oleate or methyl linoleate.
Abstract: Biosynthesis of 6-pentyl-α-pyrone byTrichoderma harzianum in two different media was evaluated. Best yields were found in nitrogen deficient medium (C/N=60). Limited growth seems to favour the production of this lactone. When fungal cells, precultured in low nitrogen medium, were incubated on methyl ricinoleate (10 g/l, C/N=60) an increase in 6-pentyl-α-pyrone production was observed in comparison with the media containing methyl oleate or methyl linoleate.
TL;DR: The antagonist strains Gliocladium virens G2 and Trichoderma harzianum T3 originally isolated from Pythium suppressive peat, and two benomyl-resistant strains of T. harZianum, T12B and T95, were evaluated as biological control agents of damping-off and root rot of cucumbers in sphagnum peat caused by Pythium ultimum.
Abstract: The antagonist strains Gliocladium virens G2 and Trichoderma harzianum T3 originally isolated from Pythium suppressive peat, and two benomyl-resistant strains of T. harzianum, T12B and T95, were evaluated as biological control agents of damping-off and root rot of cucumbers in sphagnum peat caused by Pythium ultimum. All strains were equally effective when applied as 1 % peat-bran preparations, whereas the effectiveness of disease control was reduced at higher concentrations of the antagonists. The two wild-type strains were also found to be effective when applied as conidial suspensions, and in this case no reduction in disease control was seen at higher concentrations. G. virens G2 and T. harzianum T12B showed antibiotic activity against P. ultimum in in vitro tests; however there were no signs of mycoparasitism of P. ultimum by any of the antagonist strains.
TL;DR: Scanning electron microscopy showed that Trichoderma polysporum, T. harzianum and T. viride were mycoparasites on the rhizomorphs of Armillaria gallica that attacked and penetrated the melanized outer tissue of therhizomorph and once inside they killed theArmillaria hyphae by coiling and direct penetration.
Abstract: Scanning electron microscopy showed that Trichoderma polysporum, T. harzianum and T. viride were mycoparasites on the rhizomorphs of Armillaria gallica. These Trichoderma species attacked and penetrated the melanized outer tissue of the rhizomorph and once inside they killed the Armillaria hyphae by coiling and direct penetration. After one week the rhizomorphs infected with each of the three species of Trichoderma were devoid of hyphae.
TL;DR: There was a significant decrease in the disease incidence when T. harzianum was incorporated into sterile soil, whereas the effect was insignificant in natural soil.
Abstract: Trichoderma harzianum rendered Pythium aphanidermatum and P. myriotylum non-viable in Petri dish dual culture. The Pythium mycelia from such cultures showed natural autofluorescence in the regions of interactions, indicating their death. Non-volatile and volatile fungicidal activities were detected in T. harzianum culture. Lytic activity of β-(l,3)-glucanase was detected on the cell walls of the Pythium spp. There was a significant decrease in the disease incidence when T. harzianum was incorporated into sterile soil, whereas the effect was insignificant in natural soil.
Patent•
13 Nov 1992TL;DR: The use of osmoticants to provide desiccation tolerance to growth producing cells of microorganisms upon drying and reconstitution was first proposed in this paper, which relates in part to the discovery of liquid fermentation media permitting production of high levels of conidia of Trichoderma harzianum in liquid fermentation.
Abstract: This invention relates in part to the use of osmoticants to provide desiccation tolerance to growth producing cells of microorganisms upon drying and reconstitution. This invention also relates in part to the discovery of liquid fermentation media permitting production of high levels of conidia of Trichoderma harzianum in liquid fermentation, and modifications to these media that produce conidia that are resistant to desiccation and that provide enhanced biocontrol efficacy.
TL;DR: Molecular analysis of transformants showed the integration of the transforming DNA into the genome and indicated that the number and sites of integration varied among the transformants.
Abstract: We have developed a transformation system for Trichoderma hamatum and Trichoderma harzianum Rifai, using dominant markers for selection based on the Escherichia coli hygromycin B phosphotransferase gene (hph) and the β-tubulin gene (bml) from Neurospora crassa, respectively. Transformation frequencies and protoplast regeneration were low in both species. All the T. hamatum hygromycin-resistant transformants analysed were mitotically stable, in contrast to those of T. harzianum derived by benomyl resistance, in which only 50% of the transformants analysed were stable. Molecular analysis of transformants showed the integration of the transforming DNA into the genome and indicated that the number and sites of integration varied among the transformants.
TL;DR: Two filamentous fungi, Trichodma harzianum and Trichoderma viride, were compared for their ability to synthesize lipids on different carbon and nitrogen sources: the glucose-ammonium sulphate medium was the most conducive to lipid production.
Abstract: Two filamentous fungi, Trichoderma harzianum and Trichoderma viride, were compared for their ability to synthesize lipids on different carbon and nitrogen sources. Three culture media were selected for each strain after preliminary screening. All the test media were nitrogen-deficient (C/N = 60) so as to stimulate lipid accumulation. For both microorganisms the glucose-ammonium sulphate medium was the most conducive to lipid production: a lipid accumulation of 17% (w/w) of biomass dry weight was obtained for T. harzianum and of 32% (w/w) of biomass dry weight for T. viride. In sucrose-sodium nitrate medium T. harzianum was able to accumulate almost 25% (w/w) of its biomass in lipid form. However the small quantity of biomass produced (2 g dry weight/l) limited the quantity of lipid obtained. Neutral lipids, free fatty acids and phospholipids were monitored during 8 days of cultivation of the two fungi.
TL;DR: Northern analysis showed that the expression of the igh gene in T. harzianum is not inhibited by external histidine and the level of igh mRNA was about threefold higher in cells starved of histidine.
Abstract: The Trichoderma harzianum imidazoleglycerolphosphate dehydratase gene (igh) has been isolated by complementation of a Saccharomyces cerevisiae his3 mutant using a direct expression vector. This Escherichia coli-yeast shuttle vector was developed to allow efficient cloning and expression of cDNA libraries. The cDNA is 627 nucleotides long and codes for a protein of 209 amino acids with an apparent molecular mass of 22 466 daltons. The predicted protein sequence showed 63.6%, 58.7%, and 38.4% identity respectively to the corresponding enzymes from S. cerevisiae, Pichia pastoris and E. coli. Northern analysis showed that the expression of the igh gene in T. harzianum is not inhibited by external histidine and the level of igh mRNA was about threefold higher in cells starved of histidine.
01 Jan 1992
TL;DR: This paper deals with biocontrol production, formulation and marketing in the context of “progress and challenges for the future”.
Abstract: This paper deals with biocontrol production, formulation and marketing in the context of “progress and challenges for the future”. This is itself a challenge and an extremely diverse area to cover as there is little evidence of the future organisms which require fermentation and formulation. There are few real products on the world market such as bacteria (Pseudomonas fluorescens, Dagger G. T. M., Ecogen Inc) and streptomycetes (Streptomyces griseoviridis, Mycostop T. M., Kemira Oy), (Landenpera et al., 1991). Phycomycetes (Pythium oligandrum) (McQuilken et al., 1990) and other fungi (Trichoderma harzianum), (Chet, 1990) have been developed or have been close to development as products against soilborne pathogens. Agrobacterium radiobacter has been the basis for small product for some years (Kerr, 1972) and Bacillus subtilis has been used as the growth promoter Quantum 4000 (Gustafson).
TL;DR: An economical medium consisting of a mineral salts solution, colloidal chitin, and sucrose that supported high yields of both conidia and chitinolytic enzymes was identified and may aid commercialization of T. harzianum by reducing the costs of two separate and valuable products.
TL;DR: Guanidine thiocyanate significantly increased total fungal populations relative to populations of other treatments and chitinolytic fungi increased synergistically when Gt and guanylurea sulfate were applied in combination.
Abstract: Populations of microorganisms from soil treated with guanidine thiocyanate, guanylurea sulfate, thiourea, or furfural were compared with those of untreated soil. The materials effected quantitative and/or qualitative changes in composition of the soil microflora depending on the compound used. Guanidine thiocyanate (Gt) significantly (p≤0.05) increased total fungal populations relative to populations of other treatments. Populations of Penicillium purpurogenum were markedly higher in Gt-treated soil. Gt also increased total bacterial populations, and was the only compound that increased actinomycete populations. The relative percentage of Trichoderma harzianum was significantly higher in soil treated with thiourea than in the other treatments. Furfural increased the percentage of P. purpurogenum with respect to total fungi, and was as effective as guanylurea sulfate in increasing chitinolytic bacteria and those in the Pseudomonas cepacia-group. Thiourea most effectively promoted proliferation of coryneform bacteria. Chitinolytic fungi increased synergistically when Gt and guanylurea sulfate were applied in combination.
TL;DR: Treatment of Citrus (orange, lemon and grapefruit seedlings and fruits and leaves from adult trees with pectinase obtained from Alternaria chlamydospora) showed that grapefruit tissues were the most sensitive to the action of the enzyme, as determined by the amount of reducing sugars released during the treatment.
TL;DR: The biosynthesis of harzianolide by Trichoderma Harzianum is shown to involve two rearrangements and the decarboxylation of a heptaketide.