Trichoderma harzianum secretome and its efficacy in biocontrol

Trichoderma harzianum crude extract was prepared and its controlling effect on a wide range of Gram positive and negative bacteria، and a few fungal species was evaluated via disk assay techniques. The extract was able to control pathogenic bacteria including Escherichia coli، Bacillus subtilis، Pseudomonas fluorescens، Salmonella typhi، Staphylococcus aureus، two Xanthomonas citri pathovars (NIGEB-88 and NIGEB-9322)، and two fungal pathogens، namely Macrophomina phaseolina and Rhizoctonia solani. However، it failed to control a pectobacter، Erwinia amylovora. The biocontrol efficacy of crude extract was lost once treated with trypsin and reduced in the presence of SDS، indicating the protein nature of the effective materials in the fungal extract. The antimicrobial protein was resisted 100 °C for 30 min and was active in a wide range of pH (4-9). Our data is indicative of an efficient isolation of novel fungal thermostable antimicrobial proteins with the potential to be used as a biocontrol agent in the future.