Macrocystis pyrifera source of nutrients for the production of carotenoids by a marine yeast Rhodotorula mucilaginosa.

Abstract

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% ww-1 of protein and 20% ww-1 of carbohydrate; the main sugar in this fraction was trehalose (78%). The culture conditions that maximize the total pigment concentration (1·84±0·03mgl-1 ) were initial pH equal to 7, yeast extract as nitrogen source at a concentration of 4gl-1 , seaweed extract concentration at 25% v v-1 , incubation performed at 25°C and 150revmin-1 during 6days. 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 1·84mgl-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.