A Study Exploring the Effects of Cell Disruption Techniques on Lipid Recovery in Co-cultivated Microalgae and Oleaginous Yeast

Abstract

Co-cultivation and effective downstream processing of microalgae and oleaginous yeast are potential strategies to enhance lipid yield. The findings of this work suggest that each cultivable partner should be screened and optimized for the best mutualistic co-cultures. In this case, T. pullulans was found to be the most effective yeast culture with microalgae S. obliquus, C. sorokiniana, and C. protothecoides along with additional cell disruption techniques. Co-cultures of C.protothecoides and T.pullulans had the highest relative lipid yield (RLY) of 68.71%, 59.32%, 55.33%, 53.19%, and 47.3% with sonication, microwave, osmotic shock, freeze-drying, and autoclave, respectively. Sonication was concluded as the best disruption technique with five out of nine co-cultures showing significant lipid enhancement. Even though T. pullulans was the best yeast partner with disruption techniques, co-culture of Y. lipolytica and S.obliquus (RLY 37.11%) produced lipids which was significantly higher than that of their respective monocultures (S. obliquus RLY 23.96%, Y. lipolytica RLY 4.96%) without any disruption process. R. glutinis and Y. lipolytica produced significantly enhanced lipid yield with C.sorokiniana and S. obliquus with sonication (RLY 51.44%) and osmotic shock (RLY 57.70%), respectively. FAME analysis reported that the co-cultures produced higher percentage of total FAME nearly 100% in the case of C. sorokiniana and R. glutinis with high content of saturated fatty acids (SFAs). The presence of biofuel precursors like palmitic acid, linoleic acid, oleic acid, and heptadecanoic acid, confirms their suitability for biofuel production.Graphical Abstract