Carotenoid Formation by Staphylococcus aureus

Abstract

The carotenoid pigments of Staphylococcus aureus U-71 were identified as phytoene; ζ-carotene; δ-carotene; phytofluenol; a phytofluenol-like carotenoid, rubixanthin; and three rubixanthin-like carotenoids after extraction, saponification, chromatographic separation, and determination of their absorption spectra. There was no evidence of carotenoid esters or glycoside ethers in the extract before saponification. During the aerobic growth cycle the total carotenoids increased from 45 to 1,000 nmoles per g (dry weight), with the greatest increases in the polar, hydroxylated carotenoids. During the anaerobic growth cycle, the total carotenoids increased from 20 nmoles per g (dry weight) to 80 nmoles per g (dry weight), and only traces of the polar carotenoids were formed. Light had no effect on carotenoid synthesis. About 0.14% of the mevalonate- 2 - 14 C added to the culture was incorporated into the carotenoids during each bacterial doubling. The total carotenoids did not lose radioactivity when grown in the absence of 14 C for 2.5 bacterial doublings. The total carotenoids did not lose radioactivity when grown in the absence of 14 C for 2.5 bacterial doublings. The incorporation and turnover of 14 C indicated the carotenes were sequentially desaturated and hydroxylated to form the polar carotenoids.