Identification of an acidic α-amylase from Alicyclobacillus sp. A4 and assessment of its application in the starch industry

► We isolated an acidic α-amylase from thermoacidophilic Alicyclobacillus sp. A4. ► Its nucleotide sequence was identified from the whole genome of strain A4. ► The deduced amino acid sequence shared 64% identity with its closest homolog. ► AmyA4 exhibited some superior properties over than other known α-amylases. ► AmyA4 and commercial glucamylase hydrolyzed raw starch efficiently in one step.