Use of low-cost agro products as substrate in semi-continuous process to obtain carotenoids by Sporidiobolus salmonicolor

- Natural pigments have been produced by submerged fermentation.
- The carotenoids production becomes an alternative for the harnessing of agroindustrial substrates.
- The semi-continuous process consists of a series of sequential operations that optimize the medium (agroindustrial substrates) of carotenoid production. Semi-continuo has an increase of approximately 55% in concentration of carotenoids when compared to the fed-batch process.

This work has studied the semi-continuous carotenoids production by Sporidiobolus salmonicolor (CBS 2636) comparing the use of complex substrates and agroindustrial residues. The maximum total carotenoids concentration was 4376 μg L−1 in a 264 h period with complex substrates (80 g L−1 glycerol, 5 g L−1 malt extract, and 15 g L−1 peptone) and 7388 μg L−1 in a 288 h period with agroindustrial residues (80 g L−1 crude glycerol, 80 g L−1 corn maceration water, and 20 g L−1 rice parboiling water), showing an of approximate 54% increase, under the following conditions: 25 °C, pHinitial of 4.0, 180 rpm agitation rate, 1.5 vvm aeration rate, with 50% working volume cut. The maximum productivity on total carotenoids was 34.8 and 41.4 g L−1 h−1, the maximum productivity on cells was 0.058 and 0.104 g L−1 h−1, with specific maximum growth speeds of 0.05 and 0.08 h−1, obtaining the major carotenoid all-trans-β-carotene (83% and 81%), respectively.