Increased astaxanthin production by a Phaffia rhodozyma mutant grown on date juice from Yucca fillifera

The wild strain and the astaxanthin-overproducing mutant strain 25–2 of Phaffia rhodozyma were analyzed in order to assess their ability to grow and synthesize astaxanthin in a minimal medium composed of g L−1: KH2PO4 2.0; MgSO4 0.5; CaCl2 0.1; urea 1.0 and supplemented with date juice of Yucca fillifera as a carbon source (yuca medium). The highest astaxanthin production (6170 μg L−1) was obtained at 22.5 g L−1 of reducing sugars. The addition of yeast extract to the yuca medium at concentrations of 0.5–3.0 g L−1 inhibited astaxanthin synthesis. The yuca medium supported a higher production of astaxanthin, 2.5-fold more than that observed in the YM medium. Journal of Industrial Microbiology & Biotechnology (2000) 24, 187–190.