Enzymatic degradation of bacterial biofilms using Aspergillus clavatus MTCC 1323

Fungal strain, Aspergillus clavatus MTCC1323 under solid state fermentation was found to produce enzymes (protease, amylase and pectinase) having potential of degrading the biofilms of Pseudomonas aeruginosa, Bacillus subtilis and Staphylococcus aureus. Maximum specific enzyme activities were found to be 10.0, 8.0, and 10.086 U/mg for protease, amylase and pectinase, respectively, after 7 days of incubation at 27°C. Biofilms’ degradation was analyzed through FTIR technique. Various proteins and carbohydrates were involved in the formation of biofilms as their concentrations were reduced after enzyme mixture treatment. The degradation of the biofilms was analyzed by viability assay using flow cytometry and fluorescence microscopy. Maximum biofilm degradation was found against P. aeruginosa and B. subtilis biofilms and showed 82 and 75% biofilm reduction, respectively, in terms of dry cell weight. Flow cytometry viability assay results indicated that the enzyme mixture of A. clavatus was capable of degrading the bacterial biofilms.

[1]  M. Vieira,et al.  A review of current and emergent biofilm control strategies , 2010 .

[2]  B. Christensen.  The role of extracellular polysaccharides in biofilms , 1989 .

[3]  I. Sutherland.  Biofilm exopolysaccharides: a strong and sticky framework. , 2001, Microbiology.

[4]  L. Passerini,et al.  Biofilms on indwelling vascular catheters , 1992, Critical care medicine.

[5]  L. Gram,et al.  Enzymatic removal and disinfection of bacterial biofilms , 1997, Applied and environmental microbiology.

[6]  C. Sanjosé,et al.  Bacterial biofilm removal using fungal enzymes , 2006 .

[7]  P. Stewart,et al.  A microtiter-plate screening method for biofilm disinfection and removal. , 2003, Journal of microbiological methods.

[8]  R. Tipson.  Infrared Spectroscopy of Carbohydrates: A Review of the Literature , 1968 .

[9]  T. E. Cloete,et al.  Protease and amylase enzymes for biofilm removal and degradation of extracellular polymeric substances (EPS) produced by Pseudomonas fluorescens bacteria , 2010 .

[10]  J. Costerton,et al.  Microbial Biofilms , 2011 .

[11]  M. V. van Loosdrecht,et al.  Biofilm-control strategies based on enzymic disruption of the extracellular polymeric substance matrix--a modelling study. , 2005, Microbiology.

[12]  K. Peek,et al.  Effect of culture conditions on the production of an extracellular proteinase byThermus sp. Rt41A , 1994 .

[13]  A F Molland,et al.  AN INVESTIGATION INTO THE VARIATION OF SHIP SKIN FRICTIONAL RESISTANCE WITH FOULING , 1985 .

[14]  Roberto Kolter,et al.  Initiation of biofilm formation in Pseudomonas fluorescens WCS365 proceeds via multiple, convergent signalling pathways: a genetic analysis , 1998, Molecular microbiology.

[15]  C. Faille,et al.  Using enzymes to remove biofilms of bacterial isolates sampled in the food-industry , 2010, Biofouling.

[16]  D. Naumann.  Infrared Spectroscopy in Microbiology , 2006 .

[17]  G. L. Miller.  Use of Dinitrosalicylic Acid Reagent for Determination of Reducing Sugar , 1959 .

[18]  H. Flemming,et al.  Relevance of microbial extracellular polymeric substances (EPSs)--Part I: Structural and ecological aspects. , 2001, Water science and technology : a journal of the International Association on Water Pollution Research.