Regulation of Acyl Homoserine Lactone Synthesis in Pseudomonas putida JMQS1 Under Phenol Stress

Abstract

The cell density-dependent gene expression in gram-negative bacteria is through the activity of acyl homoserine lactone signal molecules. The novel strain Pseudomonas putida JMQS1 isolated from detergent-contaminated soil exhibited quorum sensing along with its ability to degrade phenol. The response to Chromobacterium violaceum DSTS-1 mutant biosensor and luxI and luxR gene-specific amplification was used to characterize the quorum sensing property of the isolate. A regulation in the synthesis of various acyl homoserine lactone molecules, viz C₆HSL in the initial stages of phenol stress, C₈HSL during degradation, and 3OC₁₂HSL on completion of degradation could be identified by liquid chromatography-quadrupole time of flight. Thin-layer chromatography, Fourier transform infrared spectroscopy, and gas chromatography mass spectrometry confirmed the complete degradation of phenol in 48–56 h. P. putida JMQS1 exhibited adaptation over phenol stress through the selective activation of the quorum sensing signal molecules depending on the changing physiological conditions. This study proposes an efficient method for enhancing the degradation of toxic organic pollutants by the supplementation of acyl homoserine lactone signal molecules.