Influence of Diphenylamine on Carotene Synthesis and Accumulation of its Precursors in Light and Dark Cultures of Phycomces blakesleeanus

Abstract

Summary Phycomyces blakesleeanus cultivated in light or permanent darkness shows a similar decrease of its β-carotene concentration in the presence of diphenylamine. Furthermore, both culture methods result in the same I 50 values. From the 5 th to the 10 th cultivation day the precursor pattern of β-carotene shifts towards the more dehydrated and cyclized compounds. The total carotene content increases in white light whereas dark cultures show no further carotene synthesis after the 5 th day. The increasing β-carotene formation after the exposure of darkgrown cultures to light is totally inhibited by diphenylamine. As an exception from the normal growth conditions the typical accumulation of β-carotene precursors found in cultures treated with diphenylamine from the beginning was suppressed in these experiments. Consequently a second target of inhibition for diphenylamine was discussed.