Studies on the Effect of Fungal Enzymes on Bacterial Biofilm Inhibition
The microorganisms in biofilms live in a self-produced matrix of hydrated extracellular polymeric substances (EPS) that mainly comprises of polysaccharides, proteins, nucleic acids and lipids and provide mechanical stability to the biofilms by mediating their adhesion to surfaces and forming a cohesive, three-dimensional polymer network that interconnects and transiently immobilizes biofilm cellsThe mainaim of this study was to analyse the potential use of fungal enzymes like polysaccharidases,lipases and proteases as a biofilm control agent against Staphylococcus aureus and Klebsiella pneumoniae, the two most important human pathogens commonly associated with contamination in medical devices. Aspergillus niger and Penicillium chrysogenum were grown on nine different substrates to induce polysaccharidases, proteases and lipases. Starch, maltose and pectin were used to induce polysaccharidases. Similarly egg albumin, bovine serum albumin and casein was used to induce proteases .Olive oil, palm oil and glycerol was used to induce lipases. Our results demonstrated that among the two organisms used, Penicillium chrysogenum was better producer of polysaccharidases, lipases and proteases
compared to Aspergillus niger. As compared to a positive control Gentamycin (10mg/ml) which showed 90 % inhibition of both Klebsiella pneumoniae and Staphylococcus aureus, proteases were found to inhibit Klebsiella biofilms by 98% compared to polysaccharidases(40%) and lipases(40%). In case of Staphylococcus aureus biofilms lipases showed 93% inhibition compared to polysaccharidases(70%) and proteases (70%).Thus the application of these fungal enzymes for the control of bacterial biofilms would provide an interesting alternative in industrial and medical applications.