Studies in carotenogenesis. 12. The effect of temperature and thiamine concentration on carotenogenesis by Phycomyces blakesleeanus

Abstract

Beta-Carotene synthesis by P. blakesleeanus was greater at 25[degree] than at 3-5, 20 or 30[degree]. At all temperatures, beta-carotene was the major pigment produced. There was no indication of the synthesis of enhanced, amounts of more saturated polyenes at temperatures where beta-carotene synthesis was reduced. beta-Carotene synthesis is inhibited in P. blakesleeanus grown on media containing less than 0.2 [mu]g thiamine/100 ml, while growth inhibition begins below a much higher level (2.0 [mu]g/100 ml). No qualitative changes in polyene synthesis were associated with this inhibition of carotenogenesis.