A Preliminary Study on the Amylolytic Activity of Plectosphaerella cucumerina Isolate OZ-08

Alpha-amylase enzymes, highly preferred in the industry, are produced by many living things in nature. Wildtype species can be genetically modified and improved to produce more alpha-amylase. Therefore, new strains need to be discovered for more efficient alpha-amylase production. This study aimed to discover new producer fungi species to improve the production capacity of the enzyme and increase its quality. For this purpose, samples were taken from potato fields and a flour factory in Erzurum. The samples were incubated in media containing starch as the sole carbon source for the selective isolation of fungi. Then, it was treated with iodine vapor, and the zone diameters were examined. Isolate OZ-08 was selected with the largest zone diameter. The zone diameter of isolate OZ-08 was similar to that of pure amylase. Isolate OZ-08 was incubated with shaking in a liquid culture for 5 days for protein extraction. The amylase enzyme was partially purified by TCA method and the optimum temperature and pH were determined. The SDS-PAGE determined that the enzyme was approximately 70 kDa in size, and it showed optimum activity at 45 °C (201.84 U/ml) and pH 5 (227.03 U/ml). The OZ-08 isolate was then identified at the molecular level based on its ITS regions. ITS sequence analysis showed that isolate OZ-08 was identified as Plectosphaerella cucumerina using the BLASTN program. The sequence data was deposited in the GenBank database with accession number OR291433. This is the first report in the literature on the amylase activity of P. cucumerina. Isolate OZ-08 can be used as a template for future recombinant enzyme production studies.