Cocktail of carbohydrases from Aspergillus niger: an economical and eco-friendly option for biofilm clearance from biopolymer surfaces

Arashdeep Kaur,Praveen Rishi,Shania Vij,Sanjeev Kumar Soni

doi:10.1186/s13568-021-01183-y

Abstract

Biofilm formation on both biotic and abiotic surfaces accounts for a major factor in spread of antimicrobial resistance. Due to their ubiquitous nature, biofilms are of great concern for environment as well as human health. In the present study, an integrated process for the co-production of a cocktail of carbohydrases from a natural variant of Aspergillus niger was designed. The enzyme cocktail was found to have a noteworthy potential to eradicate/disperse the biofilms of selected pathogens. For application of enzymes as an antibiofilm agent, the enzyme productivities were enhanced by statistical modelling using response surface methodology (RSM). The antibiofilm potential of the enzyme cocktail was studied in terms of (i) in vitro cell dispersal assay (ii) release of reducing sugars from the biofilm polysaccharides (iii) the effect of enzyme treatment on biofilm cells and architecture by confocal laser scanning microscopy (CLSM). Potential of the enzyme cocktail to disrupt/disperse the biofilm of selected pathogens from biopolymer surfaces was also assessed by field emission scanning electron microscopy (FESEM) analysis. Further, their usage in conjunction with antibiotics was assessed and it was inferred from the results that the use of enzyme cocktail augmented the efficacy of the antibiotics. The study thus provides promising insights into the prospect of using multiple carbohydrases for management of heterogeneous biofilms formed in natural and clinical settings.

Highlights

Biofilms, referred to as “city of microbes”, are a consortium of microbial cells encased in extracellular polymeric substance (EPS)
For the application of enzymes for biofilm dispersal, the yields of all the enzymes were further enhanced by evaluation of interactions between the most important variables promoting enzyme production by response surface methodology (RSM) studies
Interactions between the selected parameters i.e. corn steep liquor (CSL), C aSO4, MgSO4 and tween 80 were analysed for all the enzymes in the cocktail

Summary

Introduction

Referred to as “city of microbes”, are a consortium of microbial cells encased in extracellular polymeric substance (EPS). EPS is responsible for the stability and recalcitrance of biofilm cells to host defences as well as against environmental extremities (Del Pozo and Patel 2007). The protective environment provided by the biofilm architecture makes cells much more resistant to different antimicrobials. Up to 1000-fold increased antibiotic tolerance has been reported in biofilm cells as compared to their planktonic counterparts (Rogers et al 2010). The reasons for enhanced antimicrobial resistance include physical impedance, enzymatic inactivation of the drugs, and complex metabolic layering in biofilm-associated cells (Vasudevan et al 2019).

Methods

Results

Conclusion