Magnetic combi CLEA for inhibition of bacterial biofilm: A green approach.

Abstract

In the present study different enzymes (α- amylase, trypsin, cellulase, horse-radish peroxidase and pectinex ultra clear) were studied for bacterial biofilm inhibition and Pectinex ultra clear showed best inhibition. So, m-combi-CLEA of Pectinex ultra clear was developed by cross linked enzyme aggregate (CLEA) formation on APTES (3-aminopropyltriethoxysilane) modified iron oxide nanoparticles. Different parameters were optimized and it was observed that 0.4\u202fmg/ml of protein (containing 25\u202fU/mg cellulase activity), 0.5\u202fmg/ml BSA and 10\u202fmM glutaraldehyde when incubated for 3\u202fh gives 100% enzyme activity using ethanol as the precipitant. The CLEA formed were thermally more stable as compared to free enzyme. m-combi-CLEA of Pectinex ultra clear shows 75-78% biofilm inhibition of E. coli and S. aureus. Furthermore, m-combi-CLEA can be reused till 4\u202fcycles with same efficiency. The carbohydrate contents of E. coli biofilm decreased from 64.629\u202fμg to 6.23\u202fμg and for S. aureus biofilm, it decreased from 58.46\u202fμg to 5.52\u202fμg when treated with m-combi CLEA in comparison to untreated biofilms. FTIR, darkfield illumination Fluorescence Microscopy, and Scanning Electron Microscopy was further used for characterization.