Determination of Culture Condition for Polygalacturonase Production by Rhizoctonia solani AG2-2, Causal Agent of Root Rot in Sugar Beet

• Published in: Plant pathology journal Vol. 6; no. 2; pp. 153 - 158
• Main Authors: Karimzadeh, F., Motallebi, M., Zamani, M.R., Hamze, Sh
• Format: Journal Article
• Language: English
• Published: 2007
• Subjects: Rhizoctonia solani
• ISSN: 1812-5387
• DOI: 10.3923/ppj.2007.153.158

The objective of the current research was to determine the significant parameters on the production of PG in a submerged culture of R. solani AG2-2 to study PGIP-PG interaction. Taguchi method was applied to evaluate the significant parameters for PG production. The process variables were pH (4, 4.5, 5 and 5.5), pectin as carbon source and inducer (7.5, 10, 12.5 and 15 g L super(-1)) and incubation time (2, 4, 6 and 8 days). The liquid medium also included mineral salts as in Pectic Zymogram (PZ) medium. Polygalacturonase activity was determined spectrophotometrically at 500 nm and productivity was calculated at the time of maximal extracellular enzyme activity. Pectin concentration was the most important factor in the enzyme production (34.8% contribution), whereas pH had a minimal contribution (16.9%). The optimal levels of the different factors for PG production were 12.5 g L super(-1) pectin, pH 4.5 and 6 days of incubation time at 26 degree C. A maximal productivity of 115.5 U mL super(-1) was reached in these conditions.