Growth enhancement in marine copepod, Pseudodiaptomus annandalei fed with the sodium acetate containing N/P starved medium grown, Tetraselmis suecica

Algal lipids are considered to be good raw materials towards aqua feed formulation and biofuels production, and hence, they have been investigated for decades. Using external carbon source, microalgal cultivation has been getting attention due to high biomass productivity and lipid content with flexible cultivation of algae. In this present study, a marine microalga, Tetraselmis suecica was cultivated by combined method with sodium acetate as carbon source and reciprocal nutrients concentration. The reciprocal concentration of nitrogen and phosphorus with sodium acetate supply towards lipid and fatty acid methyl esters (FAME) synthesis in terms of live feed efficiency was attempted. The highest FAME content (78.44 +/- 1.18% of DW) of alga was obtained in nil nitrogen condition with limited phosphate concentration (N0-PL) followed by N0-P (77.31 +/- 2.5% of DW) combination. Limitation of phosphate with combination of nil nitrogen (N0-PL) showed slight increment of total FAME accumulation and its higher increments resulted in mono-unsaturated fatty acids (MUFA) accumulation, indicating nitrogen starvation was a real FAME trigger under heterotrophic cultivation. Effect of heterotrophic cultivated T. suecica feeding on marine copepod Pseudodiaptomus annandalei produced higher population density (119 +/- 15 ind. L-1) in N0-P combination and high rate (71.98%) of nauplii production was obtained in N0-PL combination. These findings suggested that the heterotrophic microalgae cultivation can be practiced for aqua feed (especially for copepod cultivations) formulation as well as to phosphorous removal from wastewaters.

Automated summary

This study found that cultivating marine microalgae with external carbon source can effectively promote lipid synthesis, making them valuable for aqua feed formulation and phosphorous removal from wastewater.