PRODUCTION OF MEMBRANE VESICLES IN Pseudomonas putida IN RESPONSE TO STRESS CAUSED BY CATIONIC SURFACTANTS

HEREDIA R.M; BOERIS P.S.; A.S. LIFFOURRENA; BERGERO M F; LOPÉZ G.A; G.I. LUCCHESI

Jornada; THIRD JOINT MEETING OF THE BIOLOGY SOCIETIES OF ARGENTINA; 2015

Pseudomonas putida A (ATCC 12633) releases outer membrane vesicles (MVs) when grow with tetradecyltrimethylammonium (TTAB). Using the model of red blood cells we demonstrated that TTAB induced the crenation of the cells membrane (cells with outward membrane protrusions) by the asymmetric expansion of the outer leaflet relative to the inner one. This effect could be antagonized by compounds, such as chlorpromazine, that expand the inner leaflet of the membrane. The high content of phospholipids detected in the cells of P. putida grown with TTAB as sole carbon, nitrogen and energy source (30 nmol per milligram proteins) lead to the loss of contact between the outer membrane and the peptidoglycan. This effect, plus the results that showed that TTAB induce the curvature of the membrane, contributes to MVs biogenesis. The MVs exhibit a bilayer structure, and were found to be composed of lipopolysaccharide, proteins and phospholipids, with a marked increase of the phosphatidylglicerol content (53 % higher than the amount registered in cellular membrane). Taking into account that TTAB was detected inside the vesicles (710 mol of TTAB per mol of phospholipids) we conclude that this system of TTAB elimination appears to serve as part of the tolerance of P. putida to cationic surfactant.