Species association increases biofilm resistance to chemical and mechanical treatments

• Type: Article in International Scientific Journal
• Date: 2009

Authors

Manuel Simoes (Author) FEUP; Lucia C Simoes (Author) Other; Maria J Vieira (Author) Other

Journal

Title: Water Research

Vol. 43

Pages: 229-237

ISSN: 0043-1354

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 86 Citations

ISI Web of Science

Scopus - 109 Citations

COMPENDEX

Scientific classification

FOS: Engineering and technology > Environmental engineering

CORDIS: Technological sciences > Engineering

Other information

Authenticus ID: P-003-SCP

DOI: 10.1016/j.watres.2008.10.010

Abstract (EN): The study of biofilm ecology and interactions might help to improve our understanding of their resistance mechanisms to control strategies. Concerns that the diversity of the biofilm communities can affect disinfection efficacy have led us to examine the effect of two antimicrobial agents on two important spoilage bacteria. Studies were conducted on single and dual species biofilms of Bacillus cereus and Pseudomonas fluorescens. Biofilms were formed on a stainless steel rotating device, in a bioreactor, at a constant Reynolds number of agitation (Re(A)). Biofilm phenotypic characterization showed significant differences, mainly in the metabolic activity and both extracellular proteins and polysaccharides content. Cetyl trimethyl ammonium bromide (CTAB) and glutaraldehyde (GLUT) solutions in conjunction with increasing ReA were used to treat biofilms in order to assess their ability to kill and remove biofilms. B. cereus and P. fluorescens biofilms were stratified in a layered structure with each layer having differential tolerance to chemical and mechanical stresses. Dual species biofilms and P. fluorescens single biofilms had both the highest resistance to removal when pre-treated with CTAB and GLUT, respectively. B. cereus biofilms were the most affected by hydrodynamic disturbance and the most susceptible to antimicrobials. Dual biofilms were more resistant to antimicrobials than each single species biofilm, with a significant proportion of the population remaining in a viable state after exposure to CTAB or GLUT. Moreover, the species association increased the proportion of viable cells of both bacteria, comparatively to the single species scenarios, enhancing each other's survival to antimicrobials and the biofilm shear stress stability.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9