Environmental fate and effects of novel quorum sensing inhibitors that can control biofilm formation.

The formation of bacterial biofilms can have negative impacts on industrial processes and are typically difficult to control. The increase of antibiotic resistance, in combination with the requirement for more environmentally focused approaches, has placed pressure on industry and the scientific community to reassess biofilm control strategies. The discovery of bacterial quorum sensing, as an important mechanism in biofilm formation, has led to the development of new substances (such as halogenated thiophenones) to inhibit the quorum sensing process. However, there are currently limited data regarding the biodegradability or ecotoxicity of these substances. To assess the environmental fate and effects of thiophenones capable of quorum sensing inhibition, candidate substances were first identified that have potentially high biodegradability and low ecotoxicity using quantitative structure activity relationships. Subsequent confirmatory hazard assessment of these substances, using a marine alga and a marine crustacean, indicated that these estimates were significantly under predicted with acute toxicity values more than three orders of magnitude lower than anticipated combined with limited biodegradability. Therefore, although these quorum sensing inhibitors appear a promising approach to control biofilms, they may also have environmental impacts on certain aquatic organisms.