Proportion of β-carotene was also higher at lower temperature, whereas, more torulene was produced at higher temperature. A biosynthetic study showed that γ-carotene acts as the branch point of the carotenoid synthesis. Subsequent dehydrogenation and decarboxylation leading to torulene synthesis is known to be temperature dependent and is less active at lower temperature as compared to activity of β-carotene synthase (Simpson et al. 1964). This might be the reason for increase in β-carotene proportion at lower temperature. Maintaining cells at 5 °C for 21 days was found to block the production of torulene and torularhodin and result