An Alternative Exploitation of Synechocystis sp. PCC6803: A Cascade Approach for the Recovery of High Added-Value Products

Abstract

Microalgal biomass represents a very interesting biological feedstock to be converted into several high-value products in a biorefinery approach. In this study, the cyanobacterium Synechocystis sp. PCC6803 was used to obtain different classes of molecules: proteins, carotenoids and lipids by using a cascade approach. In particular, the protein extract showed a selective cytotoxicity towards cancer cells, whereas carotenoids were found to be active as antioxidants both in vitro and on a cell-based model. Finally, for the first time, lipids were recovered from Synechocystis biomass as the last class of molecules and were successfully used as an alternative substrate for the production of polyhydroxyalkanoate (PHA) by the native PHA producer Pseudomonas resinovorans. Taken together, our results lead to a significant increase in the valorization of Synechocystis sp. PCC6803 biomass, thus allowing a possible offsetting of the process costs.

Optimizing Phycocyanin Extraction from Cyanobacterial Biomass: A Comparative Study of Freeze–Thaw Cycling with Various Solvents

“…Similar results were obtained by Imbibo et al, who reported a 14% w / w PC extraction from wet biomass of Synechocystis sp. PCC 6803 by using 50 mM sodium acetate buffer (pH 5.5) and applying ultrasonication for cell disruption [ 38 ]. In the study of Avci et al [ 33 ], extraction of PC from lyophilized biomass of Synechocystis sp., using 0.01 M phosphate buffer (pH 7) and the FT method, was 0.4%, while when the bead-beating pretreatment method was applied, the extraction yield reached up to 17.5%.…”

Unveiling the potential of Pseudococcomyxa simplex: a stepwise extraction for cosmetic applications

“…Pigments were extracted using ethanol as solvent, as previously reported (Imbimbo et al 2023 ). Briefly, 200 mg of dry weight (D.W.) of alga were suspended in 4 mL of pure ethanol and disrupted by ultrasonication (40% amplitude, 4 min on ice, Bandelin SONOPULS HD 3200, tip MS73).…”

“…HaCaT cells were pre-treated with 90 μg/mL of ethanol extract for 2 h. Then, cells were stressed with 300 μM sodium arsenite (NaAsO 2 ) for 1 h as previously described (Sobeh et al 2019). Immediately after NaAsO 2 stress induction, intracellular ROS levels were determined by DCFDA assay, as previously reported (Imbimbo et al 2023), whereas intracellular glutathione (GSH) levels were measured by performing 5,5′-dithiobis-(2-nitrobenzoic acid) (DTNB) assay, as reported by (Laezza et al 2024).…”