Isolation and screening of Tetradesmus dimorphusand Desmodesmus asymmetricusfrom 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 dimorphusGEEL-04 and Desmodesmus asymmetricusGEEL-05 were isolated, identified, and assessed for growth kinetics, nutrients removal efficiency, and whole biomass composition. T. dimorphusshowed higher growth (1.46 OD680nm) compared with D. asymmetricus(1.16 OD680nm), and both showed 99% total nitrogen and total phosphorous removal. T. dimorphusand D. asymmetricusaccumulated 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. dimorphusand 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. dimorphusand D. asymmetricuscould be potential candidates for high biocomponents accumulation and N, P removal.