Macrocystis pyriferasource of nutrients for the production of carotenoids by a marine yeastRhodotorula mucilaginosa

To evaluate an aqueous extract of Macrocystis pyrifera as a nutrient source for the production of carotenoids by a marine Rhodotorula mucilaginosa isolated from seaweed samples. The effect of different culture conditions on the concentration of biomass and total pigments was evaluated using a Box–Behnken experimental design. The seaweed extract contained 15% w w−1 of protein and 20% w w−1 of carbohydrate; the main sugar in this fraction was trehalose (78%). The culture conditions that maximize the total pigment concentration (1·84 ± 0·03 mg l−1) were initial pH equal to 7, yeast extract as nitrogen source at a concentration of 4 g l−1, seaweed extract concentration at 25% v v−1, incubation performed at 25°C and 150 rev min−1 during 6 days. Under optimal growth conditions, three carotenoids were identified among the pigments produced by R. mucilaginosa, lycopene (38·4 ± 9·4%), β‐carotene (21·8 ± 1·5%) and astaxanthin (1·8 ± 0·3%). Carotenoids of commercial interest (lycopene, β‐carotene and astaxanthin) can be produced using a marine R. mucilaginosa cultivated with an aqueous extract of M. pyrifera as nutrient source. The total pigment concentration in the culture ranged between 0·82 and 1·84 mg l−1, and was significantly affected by the concentration of the seaweed extract, and yeast extract. This work demonstrates that M. pyrifera can be used as a nutrient source for the production of carotenoids by the marine yeast.