Extracellular hydrolytic enzyme production by pathogenic strains of Fusarium oxysporum f.sp. elaeidis.

Extracellular pectin esterase, polygalacturonase, C x cellulase and C 1 cellulase enzyme activities were detected in culture filtrates of F. oxysporum f.sp. elaeidis strains pathogenic to oil palm. The ten strains examined secreted varying amounts of these enzymes. Generally, enzyme production and pH of the culture medium increased with incubation period and attained maximum values between the 5th and 7th day. Optimum production of pectin methylesterase and polygalacturonase occurred under alkaline conditions (pH 7·1–8·4), whereas a slightly acidic condition (pH 5·7–6·0) favoured C x cellulase and C 1 cellulase production. Polygalacturonase and C x cellulase were constitutively secreted although there was increased synthesis in presence of their specific substrates.