Molecular analysis of acid-stable alpha-amylase (asAA) gene in Aspergillus niger using PCR-RFLP

Abstract

Introduction and Aim: Amylase is an important enzyme with vast applications in various industries such as food and therapeutic industries. Aspergillus niger is commercially engaged in the making of alpha-amylase. Acid-stable alpha -amylase is mostly produced with microorganisms such as Bacillus and Aspergillus. The aim of this research was the molecular investigation of the acid-stable alpha-amylase (alpha-sAA) gene in A. niger.   Materials and Methods: Sixty-three A. niger isolates were evaluated in this study.  PCR method was performed for amplification of a 347 bp DNA band of the alpha-sAA gene.  The Hpa II Restriction endonuclease was used for the digestion of PCR fragments.   Results: A 347 bp DNA fragment was recovered from 49 out of 63 (78%) isolates. After cutting the PCR products with the HpalphaII enzyme, 81.6% of isolates showed the expected band and 18.4% presented different restriction endonuclease patterns.   Conclusion: The results demonstrated the PCR-RFLP technique performed in this research was a valuable tool for analysis of the alpha-sAA gene in A. niger isolates.