Biomass and lipid accumulation of oceanic microalga Chlorella sp. in peritoneal dialysis waste fluid supplemented mixotrophic culture

Abstract

Interest in the use of microalgal biodiesel production using nutrients from wastewater has been increasing due to the cost-effectiveness of such processes. The aim of this study was to evaluate the feasibility of using peritoneal dialysis waste fluid (PDWF) from renal failure patient as an additive to the algal culture medium used for biodiesel production. The obtained PDWF contained large amounts of glucose (9.78 g L-1), nitrogen, phosphorus, and iron, along with various inorganic elements. Supplementation of the culture medium of Chlorella sp. CKC2 with 0–1000 mg L-1 of dried-PDWF (DPDWF) resulted in concentration-dependent increase in growth, with the maximum increase in biomass (1.3-fold) at 1000 mg L-1, compared to culture not supplemented with DPDWF (0 mg L-1). The lyophilized biomass exhibited the maximum amount of increased total lipid content (1.31-fold, wt%) at 1000 mg L-1, compared to the control. Differences in the fatty acid composition of supplemented and un-supplemented cultures induced no significant changes in the biodiesel properties. The results suggest that mixotrophic cultivation using readily available DPDWF as a carbon source, could provide a significantly lower-cost method for algal biodiesel production, and at the same time, provide a neat solution for disposal of dialysis-derived wastewater.