Effects of cellular stress on pigment production in Rhodotorula mucilaginosa/alborubescens AJB01 strain from the Caribbean region of Colombia

Abstract

Considering that a large proportion of industrially used pigments are toxic and potentially mutagenic, with some having carcinogenic effects, it is essential to replace them as well as eliminate them from industrial effluents. The discovery of biopigments has received considerable attention from the industry sector. The main objective of this study was to increase the production of carotenoid pigments in naturally pigmented yeast by subjecting the yeast to various cellular stresses. The fungal strain Rhodotorula mucilaginosa/alborubescens AJB01 was isolated from a food sample collected in Barranquilla, Colombia, and one of the pigments produced was {beta}-carotene. This strain was subjected to various stress conditions, including osmotic stress using different salts, physical stress by ultraviolet (UV) light, and light stress using different photoperiods. The optimal growth conditions for carotenoid production were determined to be 1 min of UV light, 0.5 mg/L of magnesium sulfate, and 18:6 h light/dark period, which resulted in a carotenoid yield of 118.3 g of carotenoid per gram of yeast.