Seaweed-based biostimulant improves photosynthesis and effectively enhances growth and biofuel potential of a green microalga Chlorella variabilis

Abstract

The main aim of the present study was to determine the effects of a seaweed-based biostimulant’s supplementation on the growth of Chlorella variabilis. A liquid extract from Kappaphycus alvarezii (K-sap) was prepared and supplemented in the growth medium from 0.2 to 5% concentrations. The supplementation of K-sap increased the growth and photosynthetic performance of C. variabilis. Addition of 0.4% K-sap increased the biomass production by about 59% compared to the control culture. The highest lipid and neutral lipid productivities were observed in 0.6% K-sap-supplemented culture, which were around 50 and 100% higher than that of the control culture, respectively. Addition of 1% K-sap increased the carbohydrate accumulation in the cells by about 50%. These results suggest that the supplementation of a seaweed-based biostimulant effectively enhances the growth and biofuel potential of microalgae.