Applied Biochemistry and Biotechnology, Vol.167, No.6, 1778-1794, 2012
Antibiofilm Activity of alpha-Amylase from Bacillus subtilis S8-18 Against Biofilm Forming Human Bacterial Pathogens
The extracellular alpha-amylase enzyme from Bacillus subtilis S8-18 of marine origin was proved as an antibiofilm agent against methicillin-resistant Staphylococcus aureus (MRSA), a clinical strain isolated from pharyngitis patient, Vibrio cholerae also a clinical isolate from cholera patient and Pseudomonas aeruginosa ATCC10145. The spectrophotometric and microscopic investigations revealed the potential of alpha-amylase to inhibit biofilm formation in these pathogens. At its BIC level, the crude enzyme caused 51.81-73.07% of biofilm inhibition. Beyond the inhibition, the enzyme was also effective in degradation of preformed mature biofilm by disrupting the exopolysaccharide (EPS), an essential component in biofilm architecture. Furthermore, the enzyme purified to its homogeneity by chromatographic techniques was also effective in biofilm inhibition (43.83-61.68%) as well as in degradation of EPS. A commercial alpha-amylase enzyme from B. subtilis was also used for comparative purpose. Besides, the effect of various enzymes and temperature on the antibiofilm activity of amylase enzymes was also investigated. This study, for the first time, proved that alpha-amylase enzyme alone can be used to inhibit/disrupt the biofilms of V. cholerae and MRSA strains and beholds much promise in clinical applications.
Keywords:alpha-Amylase;Bacillus subtilis S8-18;Biofilms;Confocal Laser Scanning Microscopy (CLSM);Exopolysaccharide (EPS)