Variation in pigment production by Planococcus citreus Migula with cultural age and with sea salt concentration in the medium.

The biosynthesis of carotenoids and the type of carotenoids produced by Planococcus citreus Migula appear to be influenced by the concentration of sea salt in the medium and by the age of culture. Quantitatively, pigmentation peaks at a time corresponding to the presence of maximum cell numbers and then undergoes a rapid decline.