Identification of α-amylase gene by PCR and activity of thermostable α-amylase from thermophilic Anoxybacillus thermarum isolated from Remboken hot spring in Minahasa, Indonesia

Information of thermophilic bacteria in Indonesian hot springs is limited, especially in the province of North Sulawesi. The study aims to isolate and identify thermophilic bacteria from Remboken hot springs at Minahasa Indonesia, identify the α-amylase gene and its enzyme activity. To identify the thermophilic bacteria, it was conducted the morphological analysis and biochemistry tests. Th microbial species was identified using PCR and sequencing of 16S rRNA followed by BLAST search on the EZBioCloud database, whereas the α-amylase gene was identified by Polymerase chain reaction (PCR). Starch hydrolysis test was used to analyze α-amylase activity qualitatively. It was done using iodine method (Fuwa method). The results showed that thermophilic bacteria isolated belong to the species Ureibacillus suwonensis, Anoxybacillus thermarum, and Anoxybacillus mongoliensis. PCR analysis showed that Anoxybacillus thermarum FRM-RBK02 possesses an α-amylase gene. The strain was able to hydrolyze amylose, indicated by a clear zone around the growth; hence exhibiting α-amylase activity. The the crude amylase of Anoxybacillus thermarum FRM-RBK02 exhibited optimum activity at 80°C and pH 7.0. Overall, Anoxybacillus thermarum FRM-RBK02 has α-amylase gene and could produce thermostable α-amylase with amylolytic capability.