Studies on Carotenoid Biosynthesis and Carotenoproteins of Corynebacterium Poinsettiae ATCC 9682

Thin layer chromatography and high performance liquid chromatography were used to compare pigments of the wild type streptomycin resistant strain of C. poinsettiae with those of mutants derived from it. Possible biosynthetic pathways in carotenoid biosynthesis of the wild type were postulated on the basis of observed blocks in pigment synthesis

Isolation and Partial Characterization of Pigment Mutants of Corynebacterium poinsettie ATCC 9682

Carotenoid pigments were extracted from Corynebacteriuma poinsettiae (wild type) ATCC 9682, and from 108 mutants obtained by exposure of a streptomycin resistant strain of C. poinsettiae to ultra-violet light irradiation and N-methyl- N'-nitro-N-nitrosoguanidine. The pigments were characterized by their absorption maxima, Rf-values, and partition ratios in petroleum ether and methanol. Thin layer chromatography was used to compare pigments of the wild type with those of the mutants. Possible biosynthetic pathways in carotenoid synthesis of the wild type were postulated on the basis of the observed genetic blocks. Mutants were found which suggested the existence of a linear pathway in carotenoid synthesis from the aliphatic C4 0 molecule to the bi-cyclic C50-diol. Other mutants suggested possible alternative pathways in the biosynthesis of these pigments or the presence of intermediates not detectable by thin layer chromatography

Isolation and partial characterization of carotenoid mutants of Corynebacterium poinsettiae ATCC 9682

Carotenoid pigments were extracted from wild-type Corynebacterium poinsettiae ATCC 9682 and from mutants obtained by exposure of a streptomycin resistant strain to ultra violet (UV) irradiation or N-methyl-N-nitro-N-nitrosoguanidine. Three major pigments isolated by high performance liquid chromatography (HPLC) were characterized by their absorption maxima, partition ratios in light petroleum ether/95 per cent methanol and nuclear magnetic resonance (NMR). High performance liquid chromatography was used to compare pigments of the wild-type with those of the mutants. Mutants were found which may serve as potential candidates for the study and in depth understanding of carotenoid biosynthetic pathway(s) in this bacterium and related species at the molecular level. Keywords: Corynebacterium poinsettiae, carotenoid mutants, isolation, characterization, biosynthesisGlobal Journal of Pure and Applied Sciences Vol. 12(2) 2006: 203-21