Purification of an Exopolygalacturonase fromPenicillium viridicatum RFC3Produced in Submerged Fermentation

An exo-PG obtained from Penicillium viridicatum in submerged fermentation was purified to homogeneity. The apparent molecular weight of the enzyme was 92 kDa, optimum pH and temperature for activity were pH 5 and 50–55°C. The exo-PG showed a profile of an exo-polygalacturonase, releasing galacturonic acid by hydrolysis of pectin with a high degree of esterification (D.E.). Ions Ca 2+ enhanced the stability of enzyme and its activity by 30%. The K m was 1.30 in absence of Ca 2+ and 1.16 mg mL −1 in presence of this ion. In relation to the V max the presence of this ion increased from 1.76 to 2.07  μ mol min −1 mg −1 .