Carotenoid pigments in Rhodococcus opacus PD630

SILVA R; BARRÍ;A MABEL; MAZZUCA MARCIA; ÁLVAREZ HECTOR

BIOCELL

INST HISTOL EMBRIOL-CONICET

Lugar: Bariloche; Año: 2003 vol. 27 p. 172 - 172

0327-9545

Rhodococcus opacus PD630 is a pigmented actinomycete bacterium able to produce and accumulate triacylglycerols intointracellular inclusions. The aim of this study was to determine the identity and location of pigments in strain PD630. The production of salmon-pink pigmentation by strain PD630 was constitutive and non-light induced. Different chemical techniques were performed for the identification of pigments. A mixture of different compounds like carotenes (γ- carotene) and oxocarotenoids (xanthophylls) has been detected on the basis of their UV/visible spectra in hexane in comparison with references and thin layer chromatography. Several colourless mutants was produced by chemical mutagenesis suggesting a common biosynthetic pathway for the different kind of pigments in R. opacus PD630. Lipid inclusions containing triacylglycerols and cellular envelope were the main site of localization of pigments in strain PD630 as revealed by centrifugation of free-cell extracts in discontinuous glycerol density gradients. Preliminary results suggested that strain PD630 has a sophisticated antioxidant defence system protecting different lipophilic compartments since mixtures of carotenoids are more effective than single compound.