Overlap among desiccation and osmotic responses in Rhodococcus opacus PD630.

ALVAREZ H.M.; CESARI A.C.; SILVA R.A.; ZAMIT A.L.; ALVAREZ A.F.; RAMIREZ M.V.; MASKOW T.

Congreso; XXXVIII Reunión Anual de la Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB).; 2002

Sociedad Argentina de Investigación en Bioquímica y Biología Molecular (SAIB)

Rhodococcus spp. are non-sporulating bacteria widely distributed in semiarid Patagonia, which may represent a successful physiological adaptation to arid environments. The aim of this study was to determine whether desiccation induces the development of general or specific stress resistance of Rhodococcus opacus PD630 cells. To assess the development of cross-protection against various stress conditions in the strain PD630 under desiccation conditions, survival of exponentially and stationary grown cells as well as desiccated cells was studied after application of ethanol (9 %), high temperature (47° C), oxidative stress (360 M H2O2) and osmotic stress (2.7 M NaCl). Following desiccation, cells of strain PD630 showed increased resistance to osmotic stress whereas they were more sensitive to the application of ethanol, high temperatures and oxidative stress. The occurrence of compatible solutes in R. opacus under desiccation conditions was analyzed by HPLC. Trehalose, ectoine and hydroxyectoine as major compounds were identified in desiccated cells. Results of this study suggests that there are mechanisms specifically involved in desiccation resistance, which overlap with osmotic responses through the production of compatible solutes by cells.