Metabolic rearrangement of Rhodococcus bacteria during desiccation

ALVAREZ HM

Puerto Varas

Congreso; XXXVI Annual Meeting Sociedad de Bioquímica y Biología Molecular de Chile- XLIX Annual Meeting Sociedad Argentina de Investigación en Bioquímica y Biología Molecular-; 2013

Sociedad de Bioquímica y Biología Molecular de Chile

Rhodococci are non-sporulating bacteria frequently found in desert environments. Desiccation is one of the most critical factors occurring in such extreme places, including several challenges such as carbon starvation, osmotic, oxidative and hydric stresses. In order to understand the metabolic adaptation of Rhodococcus to desiccation, we have been performing diverse genomic, transcriptomic and physiological studies. Our results indicated that rhodococcal cells maintain active their metabolism, and exert a metabolic rearrangement to cope desiccation. The mobilization of stored triacylglycerols was essential for cells survival under these conditions. A wide set of genes encoding lipases, enzymes for -oxidation and glyoxylate pathways, and a respiratory NADH dehydrogenase complex, was induced under desiccation. The carbon flux through the glyoxylate shunt may reduce the amount of NADH in cells, contributing to a decrease of oxidative radicals under such conditions. Lypolisis in desiccated cells may provide precursors for compatible solutes, components of the extracellular polymeric substance (EPS) and energy production. The induction of a (Ni-Fe)-hydrogenase system may provide additional energy to cells under such conditions. The biosynthesis of diverse osmolites (trehalose, ectoine, and glycine), carotenoid pigments and an EPS, was also induced. The reorganization of metabolism seems to be a relevant component of the adaptation of rhodococcal cells to desiccation.