Zymography variation of pectinase in Aspergillus niger and Aspergillus flavus

The genus Aspergillus (Anamorph) belong to Deutromycets and have several species. Some of the species infecte human, animal, plants and nuts. Most of these species have ability to degrade plant components by production of pectinase enzyme. The species of Aspergillus flavus and Aspergillus niger are the most popular species of this genus. Although these species could be identified using morphological characters, the interspecific and intraspecific variation could not be evaluated. Regarding pectic enzyme serection by the species, pectic zymogram technique was used as a simple and usefull method to identify the species and to detect inter and intraspecific variation. Initially the collected samples were transferred to the laboratory and after preparation were transferred on the appropriate media. The pure cultures were obtained for the sample with Aspergillus characteristics. Then Aspergillus fungi were identified microscopically based on morphological characters. As a result, 40 isolates of A. niger and 30 isolates of A. flavus were recognized. Then pured sampeles were transferred to liquid media contaning citrus pectin as a sole carbon source to induce the secretion of extracellular pectinase enzymes. After incubation for an optimised period the secreted pectinase enzymes was extracted and concentrated by Cephadex G150 and then loaded on the polyacrilamide horizontal gel and electerophoresed. There were 18 zymogram patterns for A. niger and 8 for A. flavus. The results based on the comparison of the zymogram patterns showed that there is inter and intraspecific variation for studied Aspergillus species. It seems this technique could be used not only for the species identification, but also use to study of epidemiology of the fungs.