Abstract

Trichoderma species usually produce chitinases and glucanases with inhibitory effects on several phytopathogens. In this work, the effects of such enzymes activities were evaluated on Phytophthora parasitica and Fusarium oxysporum. Enriched enzyme extracts were obtained from Trichoderma asperellum, Trichoderma virens, Trichoderma gamsii and Trichoderma logibrachiatum, which were grown on supplemented media with chitin or lamminarin. Chitinase and glucanase activity were confirmed by spectrophotometric methods. T. longibrachiatum showed the highest level of total and specific activity for both hydrolytic enzymes. Filtrated media were submitted to antagonism assays and results showed that chitinases from T. longibrachiatum inhibited 15% of P. parasitica and 45% of F. oxysporum mycelial growth;on the other hand, no inhibition was detected to P. parasitica with any other media. Glucanase activity from T. longibrachiatum showed 40% of mycelial growth inhibition on F. oxysporum and no other species showed inhibitory effects.

Key words: Antibiotic, biological control, enzymes, phytopathogens.