A carotenoid-producing yeast strain, isolated from the sub-arctic, marine copepod Calanus finmarchicus,was identified as Rhodosporidium babjevae(Golubev) according to morphological and biochemicalcharacteristics and phylogenetic inference from the
small-subunit ribosomal RNA gene sequence. The totalcarotenoids content varied with cultivation conditions in the range 66–117 lg per g dry weight. The carotenoid
pool, here determined for the first time, was dominated by torularhodin and torulene, which collectively constituted 75–91% of total carotenoids under various regimes
of growth. b-Carotene varied in the range 5–23%.A high-peptone/low-yeast extract (weight ratio 38:1)marine growth medium favoured the production of
torularhodin, the carotenoid at highest oxidation level,with an average of 63% of total carotenoids. In standard yeast medium (YM; ratio 1.7:1), torularhodin averaged
44%, with increased proportions of the carotenes,torulene and b-carotene. The anticipated metabolic precursor c-carotene (b,w-carotene) constituted a minor fraction ( £ 8%) under all conditions of growth