Does ultrasound improve the activity of alpha amylase? A comparative study towards a tailor-made enzymatic hydrolysis of starch

- The role of ultrasound in the activity of alpha amylase was investigated.
- Four commercial available alpha-amylases from fungal and bacterial sources were compared.
- A Box-Behnken experimental design was used to find the optimum assay conditions for each enzyme.
- The potential role of ultrasound and its impact on the activity control of the enzyme were critically discussed.

This work reports the role of ultrasound (US) in the activity of alpha amylase through a systematic comparison of the effect of US (supplied by a US probe) in four different commercially available alpha amylases from different sources. To this end, we selected a fungal alpha amylase from Aspergillus oryzae (AOA), and three bacterial alpha amylases: one from Bacillus amyloliquefaciens (BAA), and two from Bacillus licheniformis, heat-stable (HSA) and Liquozyme (LQA). A Box-Behnken experimental design made possible to establish the optimum activity conditions for each enzyme. AOA and BAA were inactivated by US, in contrast with HSA and LQA that were activated. When compared to control experiments, US lead to modifications in the enzyme activity that ranged from −44% in BAA to +1657% in LQA. The magnitude of inactivation/activation and the physical and chemical mechanisms responsible for these responses were critically discussed and compared with the previously reported results, with a particular emphasis on the thermal effects of US. These findings revealed the potential of US to modulate the activity of alpha-amylase, which will impact in the development of tailor-made protocols for starch hydrolysis.