Sustainable Cultivation of Porphyridium cruentum via Agro-Industrial By-Products: A Study on Biomass and Lipid Enhancement

This study explored the cultivation of Porphyridium cruentum using beet molasses and corn steep liquor (CSL) as alternative agri-waste substrates. The objective was to enhance the biomass and lipid production of P. cruentum, known for its potential as an industrial EPA producer. Using a BoxBehnken Design (BBD) as part of the response surface methodology (RSM), we investigated the effects of beet molasses, CSL, and F/2 nutrients on the microalga's cultivation. The results 24 demonstrated a significant influence of these factors on the final cell count and lipid content over an 25 8-day cultivation period. Specifically, optimal growth conditions were identified at approximately 26 1.78 g/L of molasses and 1.89 g/L of CSL, yielding a cell count of 12.1 x 106 cell/mL and a lipid 27 content of 24.48%. Validation experiments reaffirmed these findings, with observed results closely 28 aligning with predicted values. This research underscores the potential of using agro-industrial by29 products for large-scale cultivation of P. cruentum, offering a sustainable approach for enhancing 30 lipid production and other biotechnological applications.