Enhancement of intracellular extraction from Oscillatoria okine and the potential use of the extract as a supplement to fetal bovine serum in animal cell culture

Abstract

A robust cell wall and well-organized thylakoid cyanobacteria can be candidates as a promising resource for C-phycocyanin (C-PC) and intracellular applications in various biotechnological areas. However, the development of extraction techniques with minimal chemical contamination to obtain the components remains an ongoing challenge. This study aimed to assess the efficacy of C-PC and intracellular extraction from Ocillatoria okeni TISTR8549 utilizing freezing-thaw (FT), pulsed electric field (PEF), and high-pressure homogenization (HPH) techniques. Additionally, the potential of O. okeni extract as a supplement and substitute for fetal bovine serum (FBS) in HaCaT cell culture was investigated. FT appeared to be the most proper method for C-PC extraction, yielding the highest purity and yield, although requiring 18 cycles for product accomplishment. PEF seemed unsuitable for intracellular component extraction from cyanobacteria with thick cell walls. The need for increased pulses resulted in thermal elevation and prolonged incubation times led to protein degradation. HPH proves to be an effective method for intracellular extraction, yielding high protein content suitable for the potential substitution of FBS in mammalian cell culture. Particularly, increasing pressure during HPH extraction leads to a decrease in protein yield. Resazurin and SRB assays revealed that adding algal extract in culture medium at concentrations of 1 % (w/v) improved HaCaT cell viability without disrupting cell morphology and metabolic processes. However, substituting algal extract in FBS resulted in cell proliferation decrease. Therefore, supplementing O. okeni extract during cell culture improved HaCaT cell proliferation, but it was unsuitable substitute for FBS in the culture medium. However, the feasibility of employing algal extracts as FBS replacements in cell culture is interesting and warrants further detailed investigation into the specific intracellular components that could serve as substitutes for FBS. Such an approach could offer an alternative source, mitigating ethical concerns and reducing costs associated with FBS usage.