Evaluation of Zosteric Acid for Mitigating Biofilm Formation of Pseudomonas putida Isolated from a Membrane Bioreactor System

Abstract

This study provides data to define an efficient biocide-free strategy based on zosteric acid to counteract biofilm formation on the membranes of submerged bioreactor system plants. 16S rRNA gene phylogenetic analysis showed that gammaproteobacteria was the prevalent taxa on fouled membranes of an Italian wastewater plant. Pseudomonas was the prevalent genus among the cultivable membrane-fouler bacteria and Pseudomonas putida was selected as the target microorganism to test the efficacy of the antifoulant. Zosteric acid was not a source of carbon and energy for P. putida cells and, at 200 mg/L, it caused a reduction of bacterial coverage by 80%. Biofilm experiments confirmed the compound caused a significant decrease in biomass (−97%) and thickness (−50%), and it induced a migration activity of the peritrichous flagellated P. putida over the polycarbonate surface not amenable to a biofilm phenotype. The low octanol-water partitioning coefficient and the high water solubility suggested a low bioaccumulation potential and the water compartment as its main environmental recipient and capacitor. Preliminary ecotoxicological tests did not highlight direct toxicity effects toward Daphnia magna. For green algae Pseudokirchneriella subcapitata an effect was observed at concentrations above 100 mg/L with a significant growth of protozoa that may be connected to a concurrent algal growth inhibition.

Low density polyethylene functionalized with antibiofilm compounds inhibits Escherichia coli cell adhesion

“…Obtained results are in line with previous data obtained with ZA and SA free in solution, suggesting that the molecules exert their anti‐biofilm activity even when immobilized on a surface . It is likely that both immobilized molecules may exploit their anti‐biofilm activity with a mode of action similar to that they have free in solution.…”

“…Obtained results are in line with previous data obtained with ZA and SA free in solution, suggesting that the molecules exert their anti-biofilm activity even when immobilized on a surface. 17,19,[39][40][41] It is likely that both immobilized molecules may exploit their anti-biofilm activity with a mode of action similar to that they have free in solution. It has been found that ZA targets key step involved in E. coli biofilm formation by modulating the threshold level of the autoinducer-2 signal and inducing a hypermotile phenotype unable to firmly adhere on surfaces.…”

“…An example of biocide‐free anti‐biofilm compounds is offered by the secondary metabolite of the seagrass Zostera marina , the zosteric acid. It was previously demonstrated that zosteric acid possesses the remarkable ability to counteract microbial adhesion and subsequent biofilm formation, to shape fungal biofilm architecture, to potentiate the performance of conventional antimicrobial agents and to show cytocompatibility toward soft and hard mammalian tissue cell based models . In the past years, few attempts have been made to incorporate zosteric acid into silicone coatings in order to achieve its slow release in the surrounding area .…”

“…It was previously demonstrated that zosteric acid possesses the remarkable ability to counteract microbial adhesion and subsequent biofilm formation, to shape fungal biofilm architecture, to potentiate the performance of conventional antimicrobial agents and to show cytocompatibility toward soft and hard mammalian tissue cell based models. [17][18][19] In the past years, few attempts have been made to incorporate zosteric acid into silicone coatings in order to achieve its slow release in the surrounding area. 10,20 However, to the best of our knowledge, nobody investigated the possibility to design a non-leaching, long lasting, antibiofilm material to prevent colonization of polymeric materials, by using biocide-free compounds able to hinder biofilm formation.…”

The response of Escherichia coli biofilm to salicylic acid

“…Biofilms, complex surface-associated communities of microorganisms embedded in a self-produced polymeric matrix, are up to several orders of magnitude more resistant to antimicrobial agents than their planktonic counterpart (Villa et al 2010;Cappitelli et al 2014;Polo et al 2014). As a consequence, chemical treatment to prevent biological damage often involves considerable amounts of dangerous substances (Villa et al 2012b).…”