Utilization of wastewater as nutrient media and biomass valorization in marine Chrysophytes- Chaetoceros and Isochrysis

Abstract

Microalgal cultivation in wastewater is a multi-strategic approach for the effective treatment of effluents and sustainable generation of bioenergy as well as byproducts. Rapid growth rate, efficient carbon capturing technique and wide range of tolerance are the key attributes which makes microalgae an outstanding source of renewable energy. The present work involves the comparison of remediation potential of marine diatom Chaetoceros and haptophyte Isochrysis when cultivated on wastewater optimized nutrient media. The results show that both the strains can effectively remediate total nitrite up to 0.63% by T2 of Chaetoceros and 5.57% by T3 of Isochrysis, Remediation of total phosphorous 83–84% by T3 and T4 of Chaetoceros and almost 84–94% by T4 and T5 of Isochrysis. The reduction in chemical oxygen demand was most effective in T3 and T4 of Chaetoceros (146–157 mg L−1) and from T4 to T6 of Isochrysis (89–93%). Further, both the rate of lipid and biomass productivity was recorded highest in T6 of Chaetoceros (0.05 and 2.79 g L−1d−1), and in T4 and T5 of Isochrysis (0.02–0.022 and 1.11–1.27 g L−1d−1), respectively. Concomitantly, triggered productivity of total PUFA from 33.5% to 71.6% in case of Chaetoceros and from 20% to 63.4% in Isochrysis highlights the scope and effectiveness of the optimized nutrient media for cultivation and sustenance of either strain in enumerating their potential as a sustainable feed and source of biofuels.

Keywords

• Biodiesel
• Microalgae
• Metabolites
• Lipid productivity
• Wastewater remediation