African Journal of
Microbiology Research

  • Abbreviation: Afr. J. Microbiol. Res.
  • Language: English
  • ISSN: 1996-0808
  • DOI: 10.5897/AJMR
  • Start Year: 2007
  • Published Articles: 5232

Full Length Research Paper

Protease and amylase enzymes for biofilm removal and degradation of extracellular polymeric substances (EPS) produced by Pseudomonas fluorescens bacteria

I. Phyllis Molobela1*, T. Eugene Cloete2 and Mervyn Beukes3
  1Department of Microbiology and Plant Pathology, University of Pretoria, Pretoria, South Africa. 2Faculty of Science, University of Stellenbosch, South Africa. 3Department of Biochemistry, University of Pretoria, Pretoria, South Africa.  
Email: [email protected]

  •  Accepted: 08 June 2010
  •  Published: 18 July 2010



Removal of biofilms is difficult. In industrial settings, both the inactivation and removal of biofilms are of huge concern. If only disinfection without the removal of attached biofilms occurs, the inactivated biofilm cells may provide an ideal environment for further adhesion and growth, resulting in a complex matrix. Microbial resistance to biocides and their negative environmental impact are the main reasons for finding alternative biofilm control strategies. Enzymes may offer such an alternative. The objective of this study was to determine the effect of commercial proteases and amylases on biofilms formed by Pseudomonas fluorescens. Biofilms were grown in diluted medium containing glass wool used as the attachment surface. Extracellular polymeric substances (EPS) were extracted and EPS composition was determined. Protease (savinase, everlase and polarzyme) and amylase (Amyloglucosidase and Bacterial Amylase Novo) activity was tested on both biofilms and on extracted EPS. After testing enzymes, biofilm integrity was evaluated by scanning electron microscopy. EPS composition consisted predominantly of proteins. Everlase and Savinase were the most effective enzymatic treatments on removing biofilms and degrading the EPS. 


Key words: Biofilms, extracellular polymeric substances, Pseudomonas fluorescens, proteases, amylases.