Evaluation of poultry waste medium and light quality for lipid accumulation in fresh water green microalgae isolate

Abstract

The global quest for production of biofuel at a competitive price with fossil fuel has driven research to the exploration of organic waste as a cost-effective growth medium for microalgal biodiesel production. In this study, poultry waste extract (PWE) was explored as growth medium for efficient biomass and some intracellular content accumulation by Chlorella sp. isolate for eight days. The analysis of the poultry waste (PW) revealed high concentrations of nitrogen (5.785%) and phosphorus (6.786 mg/L) minerals alongside magnesium, iron, zinc, potassium, manganese etc. Under phototrophic culture condition, 200 g/L PWE among the various PW concentrations tested elicited higher biomass and productivities than other PWE concentrations tested. PWE (200 g/L) yielded comparable cell biomass and lipid productivity (2.61±0.002 g/L) (0.143±0.0006 g/L/day) with the control (BG 11 medium) (3.55±0.0008 g/L) (0.152±0.004 g/L/day). White light or white+yellow lights were the most efficient in stimulating cell growth and lipid production. However, yellow light triggered significantly (P < 0.05) higher accumulation of chlorophyll-a content (9959 µg/ml) than white+yellow light (6479 µg/ml) at 200 g/L PWE concentration and more than white light at 400 g/L PWE concentration. The outcome of these research holds high prospect for simultaneous production of biolipid and chlorophyll-a by Chlorella sp using a cheap growth medium for cost-effective biodiesel production.