[Carotenoids and fatty acids in red yeasts Sporobolomyces roseus and Rhodotorula glutinis]

Abstract

Rhodotorula glutinis and Sporobolomyces roseus, grown under different aeration regimes, showed differential responses in their carotenoid content. At higher aeration, the concentration of total carotenoids increased relative to biomass and total fatty acids in R. glutinis, but the composition of carotenoids (torulene > beta-carotene > gamma-carotene > torularhodin) remained unaltered. In contrast, S. roseus responded to enhanced aeration by a shift from the predominant beta-carotene to torulene and torularhodin, indicating a biosynthetic switch at the gamma-carotene branch point of carotenoid biosynthesis. The overall levels of total carotenoids in highly aerated flasks were 0.55 mol-percent and 0.50 mol-percent relative to total fatty acids in R. glutinis and S. roseus (respectively), and 206 and 412 microg g(-1) dry weight (respectively).