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Trichoderma harzianum
About: Trichoderma harzianum is a research topic. Over the lifetime, 4731 publications have been published within this topic receiving 96796 citations.
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TL;DR: The enzymes from Trichoderma species that degrade fungal cell walls have been suggested to play an important role in mycoparasitic action against fungal plant pathogens and one of these enzymes was purified to homogeneity and showed an endolytic mode of action on pustulan.
Abstract: The enzymes from Trichoderma species that degrade fungal cell walls have been suggested to play an important role in mycoparasitic action against fungal plant pathogens. The mycoparasite Trichoderma harzianum produces at least two extracellular beta-1,6-glucanases, among other hydrolases, when it is grown on chitin as the sole carbon source. One of these extracellular enzymes was purified to homogeneity after adsorption to its substrate, pustulan, chromatofocusing, and, finally, gel filtration. The apparent molecular mass was 43,000, and the isoelectric point was 5.8. The first 15 amino acids from the N terminus of the purified protein have been sequenced. The enzyme was specific for beta-1,6 linkages and showed an endolytic mode of action on pustulan. Further characterization indicated that the enzyme by itself releases soluble sugars and produces hydrolytic halli on yeast cell walls. When combined with other T. harzianum cell wall-degrading enzymes such as beta-1,3-glucanases and chitinases, it hydrolyzes filamentous fungal cell walls. The enzyme acts cooperatively with the latter enzymes, inhibiting the growth of the fungi tested. Antibodies against the purified protein also indicated that the two identified beta-1,6-glucanases are not immunologically related and are probably encoded by two different genes.
150 citations
TL;DR: The antagonistic activities of five biocontrol agents, Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomeces natalensis, were tested in vitro against Colletotrichum acutatum and ColletOTrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops.
Abstract: The antagonistic activities of five biocontrol agents: Trichoderma harzianum, Gliocladium roseum, Bacillus subtilis, Streptomyces noursei and Streptomyces natalensis, were tested in vitro against Colletotrichum acutatum and Colletotrichum gloeosporioides, the causal agents of anthracnose disease in fruit crops The microbial antagonists inhibited mycelial growth in the dual culture assay and conidial germination of Colletotrichum isolates The two Streptomyces species exhibited the strongest antagonism against isolates of C acutatum and C gloeosporioides Microscopic examination showed that the most common mode of action was antibiosis The results of this study identify T harzianum, G roseum, B subtilis, S natalensis and S noursei as promising biological control agents for further testing against anthracnose disease in fruits
150 citations
TL;DR: A comparative evaluation, using an enzymatic extract from Trichoderma reesei RUTC30, indicated similar performance of the T. harzianum enzyme complex, being a potential candidate for on-site production of enzymes.
149 citations
TL;DR: Northern and Western analyses indicated that AGN13.1 is induced by conditions that simulated antagonism of T. harzianum, and it is proposed that this enzyme contributes to the antagonistic response of the fungus.
Abstract: Trichoderma harzianum secretes α-1,3-glucanases when it is grown on polysaccharides, fungal cell walls, or autoclaved mycelium as a carbon source (simulated antagonistic conditions). We have purified and characterized one of these enzymes, named AGN13.1. The enzyme was monomeric and slightly basic. AGN13.1 was an exo-type α-1,3-glucanase and showed lytic and antifungal activity against fungal plant pathogens. Northern and Western analyses indicated that AGN13.1 is induced by conditions that simulated antagonism. We propose that AGN13.1 contributes to the antagonistic response of T. harzianum.
148 citations
TL;DR: A cDNA of Trichoderma harzianum (chit42), coding for an endochitinase of 42 kDa, has been cloned using synthetic oligonucleotides corresponding to aminoacid sequences of the purified chit inase, revealing post-translational processing of a putative signal peptide and a second peptide of 12 amino acids.
Abstract: A cDNA of Trichoderma harzianum (chit42), coding for an endochitinase of 42 kDa, has been cloned using synthetic oligonucleotides corresponding to aminoacid sequences of the purified chitinase. The cDNA codes for a protein of 423 amino acids. Analysis of the N-terminal amino-acid sequence of the chitinase, and comparison with that deduced from the nucleotide sequence, revealed post-translational processing of a putative signal peptide of 22 amino acids and a second peptide of 12 amino acids. The chit42 sequence presents overall similarities with filamentous fungal and bacterial chitinases and to a lesser extent with yeast and plant chitinases. The deduced aminoacid sequence has putative catalytic, phosphorylation and glycosylation domains. Expression of chit42 mRNA is strongly induced by chitin and chitin-containing cell walls and is subjected to catabolite repression. Southern analysis shows that it is present as a single-copy gene in T. harzianum. chit42 is also detected in several tested mycoparasitic and non-mycoparasitic fungal strains.
147 citations