The pathogenicity of bacterial phytopathogens solely depends on cell-to-cell communication called quorum sensing (QS) which in turn regulates the genes responsible for virulence factors, phytotoxin production, biofilm formation and motility to initiate and establish the disease in hosts. Quorum quenching will be a most suitable approach to control such virulence by interfering with QS system without hampering its growth. To confirm the antiquorum sensing activity of QQ isolates, cell free lysates (10%-50%) of the isolates were tested against the growth and violacein production of Chromobacterium violaceum MCC 4212. Concentration dependant violacein inhibition was observed with all QQ isolates without any significant reduction in growth. The highest inhibiton percent of 97% shown by three of the isolates (HSL 31, HSL 32 and HSL 64) at 50% concentration. The results suggest the potential of QQ bacteria to interfere the QS activity of pathogens that could attenuate the pathogenicity and thereby, diseases without resistance development

Quorum sensing, quorum quenching, Chromobacterium violaceum, violacein inhibition, growth

All the isolates have the quorum quenching property and capable of inhibiting the quorum sensing mediated virulence without affecting the growth. Therefore, this will be further experimented for their biocontrol efficiency against bacterial phytopathogens and this will reduce the risk of resistance development in pathogens.

K. Sowmiya, K. Tamilvendan and Mohan Chavan (2022). Anti-quorum Sensing Activity by Cell Free Lysates of Quorum Quenching Bacteria in Chromobacterium violaceum MCC 4212. Biological Forum – An International Journal, 14(4a): 190-194.