Development of thermostable amylase enzyme from Bacillus cereus for potential antibiofilm activity

Abstract

The marine bacterial strain Bacillus cereus was used to produce amylase enzyme and has excellent alkali-stable and thermostable enzymatic activity. The combined effects of pH, temperature and incubation time on amylase activity were studied using response surface methodology. The amylase enzyme activity was also determined in the presence of various metal ions, chelating agents, detergents and the results showed that the maximum enzyme activity was observed in the presence of calcium chloride (96.1%), EDTA (63.4%) and surf excel (90.6%). The amylase enzyme exhibited excellent antibiofilm activity against marine derived biofilm forming bacteria Pseudomonas aeruginosa and Staphylococcus aureus in microtiter plate assay and congo red assay. Light and confocal laser scanning microscopic (CLSM) analysis were also used to confirm the potential biofilm activity of amylase enzyme. The CLSM analysis showed the inhibition of complete biofilm formation on amylase enzyme treated glass surface. Further in vivo toxicity analysis of amylase enzyme was determined against marine organisms Dioithona rigida and Artemia salina. The results showed that there is no morphological changes were observed due to the minimal toxicity of amylase enzyme. Overall these findings suggested that marine bacterial derived amylase enzyme could be developed as potential antibiofilm agent.

Keywords: Antibiofilm activity; Bacillus cereus; In vivo toxicity; Optimization; Thermostable amylase enzyme.