Multiple Roles of Extracellular Polymeric Substances on Resistance of Biofilm and Detached Clusters

Abstract

In this study, multiple roles of biofilm EPS were assessed with respect to the resistance of biofilm and detached biofilm clusters to chlorine disinfection. Strains from an opportunistic pathogen, Pseudomonas aeruginosa (wild type, EPS- and EPS+) with altered extracellular polymeric substances (EPS) secretion capabilities were tested. The impact of biofilm EPS quantity on disinfection was evaluated by monitoring biofilm viability, biofilm structure, removal of dissolved organic matter (DOM), and viability of detached biofilm simultaneously during chlorine disinfection. The obtained results suggested that the presence of EPS increased biofilm and detached biofilm resistance to chlorine in both presence and absence of DOM. The quantity of EPS had an effect on biofilm structure and the structural characteristics were closely related to both overall biofilm viability and the spatial distribution of viable cells within the biofilm. Additionally, the increased amount of EPS influenced selective removal of DOM with polar functional groups. However the DOM removal did not have a significant impact on the viability of biofilm cells during chlorine disinfection. Meanwhile, the viability of detached biofilm clusters, particularly the EPS overproducing strain, was significantly increased in the presence of DOM. The combined results suggested that biofilm EPS played multiple roles toward influencing the resistance of both biofilm and detached biofilm to disinfectant.

TTC- Based Test as an Efficient Method to Determine Antibiofilm Activity of Silver Nanoparticles

“…Composition and structure of EPS influences on biofilm integrity, both in terms of physiology and structure as well as have direct impact on physical and chemical properties as well as biological properties of biofilm. Polymer substances essentially improve adhesion as well as make up a barrier which protects bacteria cells from the impact of adverse factors such as disinfecting agents [24]. Microorganisms resistant to antibiotics in water distribution system also exhibit resistance to chlorination.…”

Dual Roles of Capsular Extracellular Polymeric Substances in Photocatalytic Inactivation of Escherichia coli: Comparison of E. coli BW25113 and Isogenic Mutants

“…The protective function has been reported to significantly increase bacterial tolerance to antibiotics and disinfectants both by limiting the transport of biocides and via a direct reaction with the EPS (14,15). The ROS produced on the surface of TiO 2 act as chemical biocides against bacteria.…”

The effect of chlorination and hydrodynamic shear stress on the persistence of bacteriophages associated with drinking water biofilms

“…; Xue et al . ). Thus, chlorine‐mediated inactivation of viruses associated with biofilms will depend both on the individual sensitivity of the virus species and on their location on biofilm‐colonized surfaces.…”