Enhancing the Production of Lipids and Antioxidants in Heterotrophic Cultures of Auxenochlorella protothecoides
Abstract
Auxenochlorella protothecoides, aside its potential for biofuels, is an excellent source of antioxidants, reaching high lipid productivity under heterotrophic conditions utilizing glucose. Glucose-fed cultures, however, experience chloroplast bleaching affecting antioxidants production. In this study, glycerol, was evaluated as a carbon source at varying carbon-nitrogen ratios in batch-cultures. Glycerol presence in glucose fed-cultures reduced, or completely eliminated, chloroplast bleaching and increased the substrate-to-biomass yield beyond its thermodynamic limit. These results, suggest that glycerol forced the photosynthetic pathway to remain active, resulting in dark carbon fixation through the Calvin-cycle reactions. The maximum cell-density and biomass productivity were 17.60 g/L and 1.91 g/L·d respectively. Cultures grown on only-glycerol showed the highest lipid yield, 149 mg-lipids/g-substrate and antioxidants yield 6.650 µmol-Trolox/g-substrate. These values were higher to those observed with sole-glucose fed-cultures by 7% and 93% respectively. The maximum antioxidant productivity reached was 12.53 µM-TEAC/L•d, value comparable to those previously reported for Haematococcus Pluvialis.
Description
Keywords
Engineering--Chemical
Citation
Ibarra Vidal, M. (2016). Enhancing the Production of Lipids and Antioxidants in Heterotrophic Cultures of Auxenochlorella protothecoides (Master's thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/25910