Mutants of Scenedesmus sp. for purifying highly concentrated cellulosic ethanol wastewater and producing biomass simultaneously

To purify cellulosic ethanol wastewater (CEW) and obtain algae simultaneously, culturing microalgae using CEW as the medium is a potentially promising technology. In this study, mutation breeding of Scenedesmus sp. induced by ultraviolet (UV) and ethyl methanesulfonate (EMS) was performed, and three mutant strains were screened using undiluted CEW. Among them, the mutant MU1 showed a high biomass yield of 1075 mg L −1 and biomass productivity of 39.81 mg L −1 day −1 , and the lipid and protein content of MU1 can reach up to 21.4 and 41.9% (dry weight of biomass), respectively. Meanwhile, the chemical oxygen demand (COD), total ammonia nitrogen (TAN), total phosphorus (TP) and chroma (CHR) removal percentages in CEW reached to 33.5, 71.2, 46.4 and 17.8%, respectively. These results indicated that MU1 is suitable for purifying CEW and producing biomass simultaneously, providing a prospective way for CEW treatment and low-cost microalgae cultivation. Graphical abstract ᅟ