Rhamnolipids biosynthesis in Pseudomonas aeruginosa in the presence of the exogenous autoinducers of intercellular cooperation

Abstract

Rhamnolipids biosurfactants are one of the most important secondary metabolites in P. aeruginosa controlled by quorum sensing system. The aim of this work was discovering of the rhamnolipids biosynthesis in P. aeruginosa in presence of exogenic autoinducers and their synthetic analogs. Study of rhamnolipids biosynthesis was performed on four Pseudomonas aeruginosa strains: АТСС 9027, АТСС 27853, ATCC 15692 and ATCC 10145 in presence of quorum sensing exogenous autoinducers: N-(3-oxo-dodecanoyl)homoserinlacton (3-oxo-С12-HSL), N-butiryl-homoserinlacton (С4-HSL), 2-heptyl-3-hydroxy-4-quinolon (PQS) and its synthetic analogs (2-octyl-, 2-nonyl- or 2-lauryl-3-hydroxy-4-quinolon). It was shown that biosurfactants biosynthesis in P. aeruginosa strains activated in late logphase, and after transition into stationary phase rhamnolipids level increase permanently, depending on incubation time. Rhamnolipids biosynthesis in "planctonic-biofilm" system was more effective than in suspension.