Studies on Microbial Utilization of Petroleum. I. Separation and Characterization of Carotenoids Produced by a Species of Brevibacterium in Hydrocarbon Media

Ten pigment fractions were separated from a Brevibacterium sp. KY-4313 in hydrocarbon fermentation. The pigments were extracted from cell with a mixture of petroleum ether and acetone, and purified by column and thin-layer chromatography. The principal carotenoid of this organism was identified as canthaxanthin (4,4′-dioxo-β-carotene) by using visible, IR, NMR, and mass spectra of the pigment. Three other pigments were characterized as β-carotene, echinenone (4-oxo-β-carotene), and 15-cis-4,4′-dioxo-β-carotene. Three carboxylic carotenoids and three other carotenoids were also separated but their structures were left unidentified. Quantitation of the pigments showed that canthaxanthin represented 53% and its cis-isomer 20% of the pigments separated from extracts. β-Carotene derivatives comprise more than 80% of the pigments. Canthaxanthin and echinenone have not previously been reported as bacterial pigments in hydrocarbon fermentation.