In-vitro Inhibitory Indices of Selected Fungal Isolates against Mycotoxin Fungi

Limited fungal-based biocontrol products are available for use against mycotoxins in food and feed industry in Kenya. In filling this gap, in-vitro inhibitory assessment of six mycotoxin and nine non-mycotoxin species isolated from Western Kenya were placed on growth media using dual and modified plating techniques to determine the percentage inhibitions, capacity to form inhibition zones and degree of general antagonism on growth of mycotoxin fungi. The cultures were incubated at 25-27oC under 12-hour dark and 12-hour light conditions aseptically. Observations were made 10 days after incubation. Fungal isolates tested for their antagonistic effect on mycotoxin fungi were MCMT4b, MCMT3, MCHB2, T. harzianum, Monascus species, Biatrospora species, P. endophytica, C. olivaceum, and Epichloe species. Mycotoxin fungi tested were A. flavus, A. parasiticus, A. nomius, P. corrylophillum, P. auratiogriseum and A. niger. More than 80% growth inhibitory indices against mycotoxin fungi were expressed by T. harzianum, MCMT3, MCMT4b and Monascus species. Also, MCMT3, MCMT4b and Monascus species formed the largest inhibition zones against mycotoxin fungi. Fungal isolates MCMT3, MCMT4b, Monascus species and T. harzianum have growth suppression effect against A. flavus, A. parasiticus, A. niger, P. corrylophillum, and P. auratiogriseum in-vitro. More elaborate identification of the unidentified fungi, genetic characterization and field efficacy assessments of these isolates is recommended.