The Carotenoid Pigments of Mycoplasma

SUMMARY: All the Mycoplasma organisms examined, which did not require a sterol as a nutrient, contained a carotenoid pigment identifiable as the hydrocarbon, neurosporene, and a carotenol. The carotenol occurred as the free alcohol, esterified with fatty acids, and in glycosidic linkage with glucose. The carotenyl glucoside in two organisms was hydrolysable with β-glucosidase, indicating the glucosidic linkage to be in the β configuration. The carotenoid compounds found in these organisms are analogous to the sterol compounds found in sterol-requiring organisms. Cholesterol supplied in the culture medium spared the synthesis of the carotenoids. Carotenols are postulated to serve in reactions which involve substrate transport and end-product transport across the cell membrane.