Chitinolytic enzymes production by different strains of Tichoderma and investigation of their antagonistic interactions against soil borne pathogens

Six strain of Trichoderma (T. viride, T. harzianum, T. reesei, T. longibrachiatum, T. koningii and T. virens) were isolated and used for chitinolytic enzyme production. Colloidal chitin was used to chitinase production and enzyme activity assay. The highest extracellular protein production and chitinase activity were observed in T. viride. Also, the highest specific activity values were observed for T. longibrachiatum, T. viride and T. koningii, respectively. The purity and composition of chitinase-rich protein samples were evaluated under denaturing conditions by SDS-PAGE. SDS-Page analysis of the crud protein showed different composition for β-1,4-N acetyl glucoseaminidase and acetyl glucosaminase in six different strain of Trichoderma. Also, biocontrol activity of all strains against Rhizoctonia solani and Maccrophomina phaseolina were investigated. All strains of Trichoderma suppressed the growth of R. solani and M. phaseolina trough the overgrowth at all experiments. The highest antagonistic activity of Trichoderma isolates agains R. solani and M. phaseolina was observed in T. harzianum, but the lowest specific activity was observed in this strain. The strain of T. viride have been showed the highest chitinase activity but due to fungal cell walls of soil borne pathogens contain more than 60% laminarin, the highest antagonistic activity was observed in T. harzianum.

Keywords:

Trichoderma spp. , Chitinase , SDS-PAGE , Antagonistic , Rhizoctonia solani , Maccrophomina phaseolina