CHANGES IN THE FATTY ACIDS OF Pseudomonas putida INDUCED BY ALUMINIUM

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

Jornada; XIX Annual Scientific Meeting. SOCIEDAD DE BIOLOGÍA DE CÓRDOBA; 2013

P. putida A ATCC 12633 grown in presence of 0.1 mM of the toxic metal aluminum (Al). The metal is adsorbed in the membrane through the formation of Al-phosphatidylcholine (PC) complexes. The isogenic mutant, P. putida PB01, which is devoid of PC, adsorbs less Al and is sensitive to the metal. The aim of this work was to establish if the response to Al stress involves changes in the fatty acids (FA) composition of P. putida A ATCC 12633. In absence of Al, the membrane of P. putida wild-type shown high levels of the saturated FA (SFA: 86.68%) and low amounts of the unsaturated FA (UFA: 13.02%). In P. putida PB01, in concordance with the absence of PC and in order to maintain stable bilayers, the UFA decreased 90% (cis-vaccenic acid (18:1cis-Δ11) and palmitoleic acid) while the SFA increased 10% (pentadecanoic acid (15:0)). In relation to parental strain, the SFA/UFA ratio in the mutant strain increased 11 fold, indicating increment the rigidity of membrane. In presence of Al, in P. putida wild-type the FA 15:0 increased 7% and the 18:1cis-Δ11 decreased 75%, leading to 4 fold increase the SFA/UFA relationship, while, in the mutant strain, the SFA/UFA ratio was similar to detected in the absence of ion. Since the changes in the SFA/UFA relationship indicate modification in membrane fluidity, these results suggest that the modifications of FA contents could be part of a defense or/and repair mechanism aimed at reducing the damage caused by Al.