Polygalacturonase Production by Sclerotinia Sclerotiorum, Causal Agent of Canola Stem Rot: Parameter Optimization Using Taguchi Approach

Submerged culture conditions for polygalacturonase production by Sclerotinia sclerotiorum (MR5) were optimized by Taguchi orthogonal array experimental design methodology. This approach facilitates the study of interaction of a large number of variables spanned by factors and their settings with a small number of experiments leading to considerable saving in time and cost for the process optimization. The objective of the current research was to determine the significant parameters on the production of polygalacturonase in a submerged culture of S. sclerotiorum. The process variables were pH, pectin as carbon source and inducer, incubation time and temperature. The liquid medium also included mineral salts as in Pectic Zymogram (PZ) medium. Polygalacturonase activity was calculated at the time of maximal extracellular enzyme activity. The optimal levels of the different factors for polygalacturonase production were 15 g l it pectin, pH 5 and 4 days 1 of incubation time at 25°C. Temperature was the most important factor in the enzyme production with 54.6% contribution, whereas pectin had a minimal contribution (3.19%).