Isolation and screening of Tetradesmus dimorphus and Desmodesmus asymmetricus from natural habitats in Northwestern China for clean fuel production and N, P removal

Isolation and screening of microalgal species from natural habitats should be a continues work to discover effective species for biofuel generation and wastewater treatment. In the current study, microalgal species namely Tetradesmus dimorphus GEEL-04 and Desmodesmus asymmetricus GEEL-05 were isolated, identified, and assessed for growth kinetics, nutrients removal efficiency, and whole biomass composition. T . dimorphus showed higher growth (1.46 OD 680nm ) compared with D . asymmetricus (1.16 OD 680nm ), and both showed 99% total nitrogen and total phosphorous removal. T . dimorphus and D. asymmetricus accumulated higher protein content (40.02 and 45.10%), carbohydrate (31.91 and 24.64%), and lipid (15.41 and 24.16%), respectively. The FTIR spectra absorbance revealed different function groups in microalgal biomass available for biofuel generation. Elemental analysis of microalgal biomass showed high carbon content 50.13% and 43.01% for T . dimorphus and D . asymmetricus , respectively. Thermogravimetric analysis indicated ≥ 80% volatile content in both isolates. The fatty acid composition of both microalgal strains showed high palmitic acid and linoleic acid corresponding to high quality biodiesel. These results indicated that the T . dimorphus and D . asymmetricus could be potential candidates for high biocomponents accumulation and N, P removal. Graphical abstract