Inhibition of biofilm formation and swarming of Bacillus subtilis by (5Z)-4-bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone

Aims: (5Z)-,4-Bromo-5-(bromomethylene)-3-butyl-2(5H)-furanone (furanone) of the marine alga Delisea pulchra was synthesized, and its inhibition of swarming motility and biofilm formation of Bacillus subtilis was investigated. Methods and Results: Furanone was found to inhibit both the growth of B. subtilis and its swarming motility in a concentration-dependent way. In addition, as shown by confocal scanning laser microscopy, furanone inhibited the biofilm formation of B. subtilis. At 40 mug ml(-1), furanone decreased the biofilm thickness by 25%, decreased the number of water channels, and reduced the percentage of live cells by 63%. Conclusions, Significance and Impact of the Study: Natural furanone has potential for controlling the multicellular behaviour of Gram-positive bacteria.