Influence of pH and temperature on the production of polygalacturonases by Aspergillus fumigatus

- Production of polygalacturonases in different concentrations of pectin and glucose.
- Effect of temperature on enzyme action and pH on the polygalacturonases.
- Potential usage of these enzymes in industrial applications.

The production of polygalacturonases (PG) by Aspergillus fumigatus LB-01-AP was evaluated in submerged process at different concentrations of pectin, glucose and initial pH values of the medium. Higher activities of endo- and exo-polygalacturonases were reported in medium without glucose and with 20 g L−1 of citrus pectin, at an initial pH of 4.0. Regarding the effect of temperature on enzyme action, it was found that the interval between 40 and 60 °C is ideal for endo-PG, while for exo-PG the highest activity was measured at 60 °C. When the crude experimental enzyme were exposed to different temperatures for up to 150 min, it was observed that about 70% of the endo-PG activity at 50 °C was preserved. Both polygalacturonases showed higher thermostability than that usually described in the literature for enzymes produced by other species of the genus Aspergillus. In addition, the enzyme preparations obtained proved free of mycotoxins, evidencing a potential of using these enzymes in industrial applications.