A comparative study of the growth of microalgae-bacteria symbiotic consortium with the axenic culture of microalgae in dairy wastewater through extraction and quantification of chlorophyll

Abstract

Microalgae-bacteria symbiotic association can provide many competitive advantages over the pure axenic culture of microalgae to obtain biofuel. This system significantly reduces an important technical constraint, including associated capital cost with the infrastructure required for maintaining pure microalgae culture. The current study aims to compare the symbiotic growth of Tetraselmis indica - Pseudomonas aeruginosa consortium with axenic growth of Tetraselmis indica in dairy wastewater (DWW). The extraction and optimization of chlorophyll-a were also investigated. The overall maximum chlorophyll-a recovery of 29.106 ± 0.045 mg L−1 was obtained through the sonification as extractant method with methanol as an extraction solvent. The chlorophyll-a content of consortium cultivated in DWW higher than the axenic pure microalgae culture (APMC). The maximum biomass yield of the consortium was achieved as 1454.88 mg L−1, which is much higher than APMC growth in DWW by 38.80%. On the 10th day, the consortium removed 87.49%, 83.76%, and 79.83% of chemical oxygen demand (COD), total dissolved nitrogen (TDN), and total dissolved phosphorus respectively. The higher biomass growth and wastewater nutrient removal exhibited by the symbiotic microalgae-bacteria consortium can be utilized in biofuel technology.