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. 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.
3. Characterization of plant growth promotion traits
Out of thirteen rhizobacterial isolates tested, nine efficiently solubilize the insoluble inorganic phosphate which is accompanied by a decline in the pH of the nutrient broth suggesting the production of organic acids by the PGPR isolates. In this study, all thirteen isolates produced IAA at different levels with P. putida PP4AM and P. putida PP1WT being the highest and lowest producers with values of 5.6 and 2.8 , respectively.