Determination of amylase activity of thermophilic fungi isolated from soil and compost in Kermanshah Province

Thermophilic fungi produce a variety of enzymes that in addition to biocatalytic activity, are widely used in biological processes in many industries, including food, paper, detergents, pharmaceuticals, toxic waste removal, and oil drilling. Extraction of enzymes, especially amylase, from thermophilic fungi has greatly contributed to industry and the global economy, so that one of the indicators of economic prosperity in developed countries. The aim of this study was to isolate and identify thermophilic fungi from soil, municipal waste compost and mushroom compost and to investigate the ability of amylase production of isolates. Isolation was performed by serial dilution method on potato-dextrose-agar extract at 45 and 50 °C. Molecular identification of isolates was performed by amplification of the ITS rDNA region (ITS1–5.8S – ITS2) using the general primers ITS1 and ITS4 during the polymerase chain reaction. The amylase activity of the isolates was studied in agar-bearing culture medium containing starch. Due to the bright halo created around the colonies after 48 hours at 37 °C, most of the isolates were able to decompose and enzymatic activity. The highest bright halo and amylase activity belong to a species of Thermomyces sp. and followed by Malbranchea cinnamomea, Thermomyces dopuntii, Thermomyces lanuginosus, Absidia sp., Aspergillus nidulance, Aspergillus fumigatus, Aspergillus niger, and Aspergillus terreus had the highest amylase activity, respectively. Thielavia arenaria and Melanocarpus albomyces showed no activity of producing amylase. This is the first comprehensive study on thermophilic fungi with ability of producing amylase in Iran. All isolates of the present study were deposited to the Iranian Plant Protection Research Institute.