Insights in cyanobacteria lipidomics: A sterols characterization from Phormidium autumnale biomass in heterotrophic cultivation

Sterol profiles were obtained from cyanobacteria Phormidium autumnale, cultivated in a heterotrophic system using three distinct sources of carbon: glucose, sucrose, and agroindustrial slaughterhouse wastewater. A simultaneous saponification-extraction ultrasound-assisted method was performed to determine sterol and other non-saponified compounds in the dry biomasses. A total of 24 compounds were observed in the biomasses, including hope-22,29-en-3-one, squalene, and 22 other sterols. Using wastewater as a carbon source, the microalgae biomass produced a diversity of sterols such as stigmasterol (455.3 μg g−1) and β-sitosterol (279.0 μg g−1). However, with glucose it is possible to produce ergosterol (1033.3 μg g−1). Squalene was found in all the cultures, with 1440.4 μg g−1, 225.4 μg g−1, and 425.6 μg g−1 for glucose, sucrose, and slaughterhouse wastewater biomasses, respectively. Several intermediate compounds from those sterols were found. These data provide the construction of the sterol metabolism according to the literature for P. autumnale heterotrophically cultured. [Display omitted] •P autumnale produced distinct sterols from different exogenous carbon source.•Squalene was a sterol precursor found in all biomasses.•Cholesterol, β-sitosterol and stigmasterol were main sterol produced by P autumnale.•High amounts of ergosterol was produced in the glucose culture.•Several sterol pathways' intermediary metabolites were identified in P autumnale.