4.2. Quorum sensing and quorum sensing inhibition
In our experiment only P. putida PP3WT produced the purple
pigmented quorum sensing signal molecule, acyl-homoserine lactone
(AHL), suggesting the capability of the isolate to communicate
within its vicinity for a diverse living and ecological activities. This
is in line with Elasri et al. (2001) who reported, that AHL production
is more common in plant associated Pseudomonas species than
among soil-borne species. Here the indicator organism C. violaceum
CV026 is unable to synthesize its own endogenous AHL inducer,
but the relevant operons can be induced by the exogenous supply
of the appropriate acyl-homoserine lactone (AHL) to the mutant
bacteria (McClean et al., 1997). In our experiment, the biosensor
C. violaceum CV026 produced the purple pigment violacein, in response
to AHL provided by the test strain PP3 WT on LB agar
medium.