title: Efficient selective breeding of live oil-rich Euglena gracilis with fluorescence-activated cell sorting.
abstract: Euglena gracilis, a microalgal species of unicellular flagellate protists, has attracted much attention in both the industrial and academic sectors due to recent advances in the mass cultivation of E. gracilis that have enabled the cost-effective production of nutritional food and cosmetic commodities. In addition, it is known to produce paramylon (β-1,3-glucan in a crystalline form) as reserve polysaccharide and convert it to wax ester in hypoxic and anaerobic conditions-a promising feedstock for biodiesel and aviation biofuel. However, there remain a number of technical challenges to be solved before it can be deployed in the competitive fuel market. Here we present a method for efficient selective breeding of live oil-rich E. gracilis with fluorescence-activated cell sorting (FACS). Specifically, the selective breeding method is a repetitive procedure for one-week heterotrophic cultivation, staining intracellular lipids with BODIPY(505/515), and FACS-based isolation of top 0.5% lipid-rich E. gracilis cells with high viability, after inducing mutation with Fe-ion irradiation to the wild type (WT). Consequently, we acquire a live, stable, lipid-rich E. gracilis mutant strain, named B1ZFeL, with 40% more lipid content on average than the WT. Our method paves the way for rapid, cost-effective, energy-efficient production of biofuel.
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Koji
authors.initials: K
authors.lastname: Yamada
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Takuto
authors.initials: T
authors.lastname: Takeuchi
authors.affiliation: Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kazama
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Sharbanee
authors.initials: S
authors.lastname: Mitra
authors.affiliation: Nishina Center for Accelerator-Based Science, RIKEN, Saitama 351-0198, Japan.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Abe
authors.affiliation: Department of Chemistry, University of Tokyo, Tokyo 113-0033, Japan.|Department of Electrical Engineering, University of California, Los Angeles, California 90095, USA.|Japan Science and Technology Agency, Tokyo 102-0075, Japan.
authors.forename: Keisuke
authors.initials: K
authors.lastname: Goda
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Kengo
authors.initials: K
authors.lastname: Suzuki
authors.affiliation: Euglena Co., Ltd., Tokyo 108-0014, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Iwata
mesh_terms: D056804:Biofuels; D001709:Biotechnology; D005056:Euglena gracilis / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism*; D005434:Flow Cytometry / Q000379:methods; D050356:Lipid Metabolism / Q000235:genetics; D058086:Microalgae / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009154:Mutation
chemical_list: D056804:Biofuels