Enhanced single-cell oil production by cold shock in cyanobacterial cultures

ABSTRACT: The aim of this research was to evaluate the enhanced single-cell oil production by cold shock in Aphanothece microscopica Nägeli using dairy processing wastewater as culture medium. The study focused on (i) temperature optimization for biomass production, (ii) cold shock application to induce lipids biosynthesis and (iii) determination of fatty acids profile under different conditions. Results indicated that temperature of 20°C was the best condition in terms of kinetics parameter, reaching biomass productivities of 160.25mg/L.h. Under these conditions, a lipid content of 12.65% was also observed, resulting in a lipid productivity of 20.27mg/L.h. Additionally, the 0°C cold shock was the most efficient in increasing intracellular lipid content, reaching 28.4% in dry weight. Cold shocks also showed influence on the saturation of fatty acid composition, where the saturated fatty acids decreased, and the monounsaturated and polyunsaturated fatty acids increased by increasing the cold application. Thus, the use of cold shocks indicates to be a key condition for improving the prospects of efficient single-cell oils production.