[Effect of monensin on the growth and secretion of exopolysaccharides in Botrytis cinerea Pers. and Sclerotium rolfsii Sacc].

The addition of various concentrations of monensin (1,5, and 10 micrograms/mL) to the culture medium inhibits the fungal growth and perturbs exopolysaccharides secretion, provoking a decrease of production in Botrytis cinerea and an increase in Sclerotium rolfsii. The ionophore induces also modifications in both polymer composition and structure. New monomers were observed in the two species and a decreased branching rate for Sclerotium rolfsii. These modifications show that monensin affects the enzymes responsible for normal wall synthesis and therefore vesicular traffic.