Effect of Trichoderma species on growth of Fusarium proliferatum and production of fumonisins, fusaproliferin and beauvericin.

摘要

Trichoderma species has been suggested as potential biocontrol agent for Fusarium verticillioides on maize. In this cereal, F. verticillioides and F. proliferatum contributed to fumonisin accumulation. In addition, F. proliferatum could produce beauvericin and fusaproliferin. The aim of this work was to evaluate the effect of Trichoderma spp. on growth and fumonisin B₁, fusaproliferin and beauvericin production by F. proliferatum. Dual cultures of F. proliferatum and T. harzianum ITEM 3636 and T. longibrachiatum ITEM 3635 on maize meal agar at 0.995 a_w were done. The effect of Trichoderma spp. on the lineal growth of F. proliferatum was determined. The effect of Trichoderma species on fumonisin B₁, fusaproliferin and beauvericin production by F. proliferatum was determined on co-inoculated maize kernels by HPLC. T. harzianum suppressed F. proliferatum growth once contact between the colonies occurred. T. longibrachiatum showed a less antagonistic effect against F. proliferatum. A reduction on fumonisin B₁ production of 98% and 88% was observed in the co-incubation of F. proliferatum with T. harzianum and T. longibrachiatum, respectively. The decrease of FB₁ production was significant even in maize kernels on which F. proliferatum had been growing 7 days prior to the addition of Trichoderma spp. The concentration of beauvericin and fusaproliferin produced during 30 days co-incubation of F. proliferatum with both Trichoderma spp. did not differ to those produced by F. proliferatum alone. These mycotoxins might enter the food chain causing so far unknown consequences to the health of domestic animals and humans. For this reason it is important, when a potential biocontrol agent is under study, to test the effect on the fungal growth and on the putative mycotoxin produced.