Açai Seeds, a Highly Discarded Byproduct in the Amazonia, as Potential Alternative Substrate for the Biotechnological Production of Carotenoids

Rhodotorula yeasts can biosynthesize carotenoids inside their cells when they are subjected to adverse environmental conditions, and this biotechnological process can be industrially viable if the production cost can be minimized using low-cost byproducts as substrates. This research investigated the production of carotenoids using açaí seeds as a substrate for R. mucilaginosa. The best conditions for the production of biomass of R. mucilaginosa were pH 7.0, 40 °C, and agitation at 200 rpm, while those for the biosynthesis of carotenoids were pH 7.0, 30 °C, and 200 rpm. The optimized conditions provided 2 g of dry biomass and total carotenoid contents of 37 μg/g of dry biomass, with β-carotene (77%), Z-γ-carotene (6.9%), and torulene (4.5%) being the major carotenoids. Therefore, the biotechnological production of carotenoids achieved by R. mucilaginosa using açai seeds deserves scientific attention as a promising alternative to the use of waste processing units as a sustainable strategy for a circular economy.