Production op high-purity carotenoids by fermenting selected bacterial strains

The present invention describes a process of production carotenoids in improved fermentation conditions of selected bacterial strains constitutively over-producing carotenoids or mutants thereof, purifying and isolating a specific crystalline carotenoid, preferably beta-carotene, for its use in the feed, food, cosmetic and pharmaceutical sectors. The present invention also describes a method for obtaining mutant strains constitutively overproducing carotenoids from naturally occurring bacterial strains, permitting the selection of mutants with high carotenoid yields and specificity towards a specific carotenoid. Additionally the invention describes the use of this method on obtained mutant strains for further improvement thereof. The present invention also describes said strains and improved conditions of fermentation for obtaining high concentrations of carotenoids and specificity towards a specific carotenoid, and further discloses purification steps, without cell disruption, for the extraction of carotenoids from the biomass.