In vitro influence of bacterial mixtures on Fusarium verticillioides growth and fumonisin B1 production. Effect of seeds treatment on maize root colonisation

LILIA CAVAGLIERI, JULIETA ORLANDOA AND MIRIAM ETCHEVERRY

LETTERS IN APPLIED MICROBIOLOGY

Blackwell Publishing

Lugar: Londres (Inglaterra); Año: 2005 vol. 41 p. 390 - 396

0266-8254

Aims: Enterobacter cloacae, Microbacterium oleovorans, Pseudomonas solanacearum and Bacillus subtilis were investigated in order to evaluate 1) the inoculum size of two bacterial mixtures on F. verticillioides growth and fumonisin B1 production in vitro at different water activities, 2) the efficacy of a seed treatment with the best bacterial mixture on F. verticillioides root colonisation in greenhouse studies. Methods and Results: the influence of bacterial mixtures (1=E. cloacae and M. oleovorans and 2=P. solanacearum and B. subtilis) to antagonise thirteen F. verticillioides strains at different inoculum concentrations (108, 109 and 1010 cells ml-1) and water activities (0.937, 0.955 and 0.982 aW) were examined. Antibiosis, growth rate, and fumonisin B1 production were determined. Bacterial mixture 1 proved to exert the most effective control. Seed treatment with mixture 1 at 108 cells ml-1 had the best inhibitory effect on F. verticillioides root colonisation. Conclusions: These results suggest that the combination E. cloacae and M. oleovorans has the potential for the biological control of F. verticillioides as a maize seed inoculant. Significance and Impact of the study: The application of this knowledge contributes to prevent the vertical transmission of F. verticillioides.