High value pigment production and carbon sequestration through wastewater grown Spirulina (Arthrospira) platensis: A green technology for wastewater utilization

Abstract

This report describes a protocol for utilization of aquaculture wastewater for biomass production, high value pigment recovery and carbon sequestration through a cyanobacterium Spirulina (Arthrospira) platensis through a green process. The dry weight (2.76 ± 0.03 g/L) was almost comparable with the control showing a negligible decrease of 0.89%. During the 6 to 8 days of the culture duration, the biomass composition of amended aquaculture wastewater demonstrated a maximum cell productivity (0.0734 ± 0.0050 g/L/day), carbon sequestration (0.0314 ± 0.0021 g/L/day) and CO2 sequestration (0.1151 ± 0.0078 g/L/day), showing a substantial 20% improvement compared to the control. The yield of a pharmaceutically important pigment phycocyanin was 101.95 ± 1.49 mg/g DW in the wastewater grown cultures showing a negligible decrease (0.83%) compared to the synthetic medium grown cultures. The reduction in the cost of the synthetic medium through utilization of aquaculture wastewaters after certain amendments is a novel approach for an environmentally friendly and cost-effective production of S. platensis. The quality of biomass and phycocyanin in amended wastewater grown cultures was not altered. This report provides baseline data about aquaculture wastewater utilization for cyanobacterial biomass production, carbon sequestration and recovery of a valuable pigment phycocyanin through a simple and low-cost downstream process.

Keywords

• Spirulina
• Wastewater utilization
• Carbon capture
• Phycocyanin
• Natural colorant