Nickel and cadmium ions inhibit quorum sensing and biofilm formation without affecting viability in Burkholderia multivorans

• Micromolar concentrations of nickel and cadmium decreased biofilm formation.
• Nickel and cadmium also decreased expression of homoserine lactone genes.
• First paper linking metals with quorum sensing and biofilm inhibition.
• Results may enable the development of novel strategies to mitigate biofouling.

Microbial influenced corrosion (MIC) and biofouling are multi-billion dollar challenges typically associated with bacterial biofilms. Using microtiter plate and quantitative reverse transcriptase polymerase chain reaction (q-PCR) assays, we show that sub-millimolar concentrations of nickel (Ni2+) and cadmium (Cd2+) inhibit biofilm formation by the bacterium Burkholderia multivorans through the inhibition (at the transcriptional level) of acyl-homoserine lactone quorum sensing (QS). These results advance the understanding of environmental factors influencing the establishment and subsequent development of biofilms, as this is the first paper linking heavy metals with quorum sensing and biofilm inhibition, and may guide strategies to mitigate MIC and biofouling of infrastructure surfaces.