Enhancement of indigenous microalgae culture using cheese whey as growth media for bioenergy and coproducts production

Abstract

This study investigates the use of cheese whey to enhance the microalgae cultivation for bioenergy and coproducts in the framework of circular economy and pollution attenuation. A local isolated indigenous Chlorella vulgaris strain using a growth medium containing BG11 and cheese whey (BG11/CW) was used. Algae density, dry weight, organic carbon consumption, biochemical composition, fatty acid profile, Total pigments were investigated. The best growth is obtained in the BG11/CW culture media, with a dry biomass and cell density of 2.5 g/L, 6.5×107 Cells/ml, respectively. This represents 5 times the dry biomass obtained in the BG11medium (0.45 g/L, 1.68×107 cells/ml). Indigenous Chlorella vulgaris growth is favored by glycose availability after lactose degradation with a consumption of 62% on the 7th day. Pigments content was improved with an average value of 34.5 mg/gDW and 9 mg/mgDW for total chlorophylls and carotenoids, respectively. Chlorella vulgaris cultivation on BG11/CW has showed a high protein content with a value of 46%. Indigenous Chlorella vulgaris was able to accumulate a suitable lipid content that could reach 23%, which are rich in C16:00, C18:00, C18:1. This strain is a potential candidate for a sustainable bioenergy and coproducts that could contribute efficiently to promote the circular economy.