Effect of coagulant/flocculants on bioproducts from microalgae

Abstract

The potential of microalgae as a source of sustainable energy, nutritional supplements and specialized chemicals necessitates a thorough evaluation of the methods of harvesting microalgae with regards to the bioproduct(s) desired. This research assessed the effect of coagulation, flocculation, and centrifugation on the wet lipid extraction procedure, which fractionated microalgae into hydrolyzed biomass for fermentation into acetone, butanol, and ethanol, an aqueous phase as growth media for genetically engineered Escherichia coli, and a lipid fraction for the production of biodiesel. Biomass harvested by cationic starches, alum, and centrifugation produced 30, 19, and 22.5mg/g of dry wt. algae of total combined acetone, butanol, and ethanol, respectively. Higher biodiesel production was also observed for the cationic starches (9.6 mg/g of dry wt. algae) than alum (0.6 mg/g of dry wt. algae) harvested biomass. The results suggested significant effect of the harvesting methods on the yields of bioproducts.

Keywords: 3-methacryloyl amino propyl trimethyl ammonium chloride; ABE; ANOVA; Analysis of Variance; Biofuels; Bioproduct; Biosolvents; CCS; CFU; CPS; Cationic starch; DCW; DS; FAMEs; MAPTAC; Microalgae harvesting; RCM; SAS; Statistical Analysis Software; WLEP; acetone, butanol, and ethanol; cationic corn starch; cationic potato starch; colony forming units; degree of substitution; dry cell weight; fatty acid methyl esters; reduced clostridia media; wet lipid extraction procedure.