Laherradurin, a natural stressor, stimulates QS mechanism involved in biofilm formation of a PAHs degrading bacterium

Laherradurin is an annonaceous acetogenin (ACG) extracted from the seeds of Annona cherimolia (Annonaceae). It has been shown to increase biofilm production of Pseudomonas plecoglossicida J26, a polycyclic aromatic hydrocarbon degrading bacterium. It is not an autoinducer agonist, and is indirectly involved in quorum sensing mechanism by inducing a stress related increase in autoinducer production, which in turn results in more biofilm formation without any significant detriment on bacterial growth rates. The results of the analysis of cells and supernatants obtained from J26 cell cultures by chromatographic techniques (TLC revealed with the Kedde reagent and RP-HPLC) and mass spectrometry (EI-MS) allowed us to determine that the ACG laherradurin and squamocin are located in the bacterial pellet, as was expected given their theoretical log p values. Thus, results suggest that these ACG act as bacterial membrane natural stressors. (C) 2013 Elsevier Ltd. All rights reserved.