Bacterial Biofilm Degradation Using Extracellular Enzymes Produced by <i>Penicillium janthinellum</i> EU2D-21 under Submerged Fermentation

Abstract

Bacterial biofilms are the bacterial aggregates that are embedded in the self-produced matrix of extracellular polymeric substances (EPS) that cause persistent bacterial infections posing significant medical challenges. They are recalcitrant to antibiotics and host defenses which make the treatments difficult and costly. Penicillium janthinellum mutant EU2D-21 was found to produce extracellular enzyme complex (amylase, cellulase, protease) under submerged fermentation. Maximum specific enzyme activities were found to be 3.04 IU/mg, 2.61 IU/mg and 3.39 IU/mg for alpha-amylase, cellulase and protease respectively, after 8 days of incubation at 30˚C. We evaluated the enzyme complex for its ability to target and degrade the biofilms of different bacteria. We found that it degraded biofilms of Escherichia coli (85.5%), Salmonella enterica (79.72%), Pseudomonas aeruginosa (88.76%) and Staphyloccus aureus (87.42%) within 1 h of incubation at 50˚C. The scanning electron microscopy (SEM), quantitation of biofilm removal assay and Crystal violet assay demonstrated that the enzyme complex detached the biofilm exo-polysaccharide matrix and bacteria from the cell surface. These results illustrate the feasibility and benefits of using this enzyme complex as anti-biofilm therapeutics to eradicate biofilms. This can also be used as a promising strategy to improve treatment of multidrug resistant bacterial infections.