title: Enhancing growth rate and lipid yield of Chlorella with nuclear irradiation under high salt and CO2 stress.
abstract: In order to produce biodiesel from microalgae cultured with abundant seawater, Chlorella sp. was mutated with (137)Se-γ ray irradiation and domesticated with f/2 seawater culture medium (salinity=3 wt.%) under 15 vol.% CO2 stress. Biomass yield of the mutant increased by 25% compared with wild species and lipid content increased to 54.9%. When nitrogen and phosphorus concentrations in the initial substrate increased, the increased propagation speed of the mutant resulted in decreased cell diameter by 26.6% and decreased cell wall thickness by 69.7%. The dramatically increased biomass yield of the mutant with sufficient initial substrate and relative nitrogen starvation in the later growth period with continuous 15 vol.% CO2 led to an increased lipid yield of 1.0 g/L. The long-chain unsaturated fatty acids increased, whereas short-chain saturated fatty acids decreased.
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
authors.forename: Jun
authors.initials: J
authors.lastname: Cheng
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Hongxiang
authors.initials: H
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Ke
authors.initials: K
authors.lastname: Li
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Huang
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Junhu
authors.initials: J
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors.forename: Kefa
authors.initials: K
authors.lastname: Cen
mesh_terms: D056804:Biofuels; D002245:Carbon Dioxide / Q000494:pharmacology*; D002588:Cesium Radioisotopes; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D005227:Fatty Acids / Q000378:metabolism; D005720:Gamma Rays; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D050356:Lipid Metabolism / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D008055:Lipids / Q000302:isolation & purification*; D058086:Microalgae / Q000187:drug effects / Q000254:growth & development* / Q000528:radiation effects; D016296:Mutagenesis; D009584:Nitrogen / Q000378:metabolism; D010758:Phosphorus / Q000378:metabolism; D012965:Sodium Chloride / Q000494:pharmacology*
chemical_list: D056804:Biofuels; D002588:Cesium Radioisotopes; D005227:Fatty Acids; D008055:Lipids; D002245:Carbon Dioxide; D010758:Phosphorus; D012965:Sodium Chloride; D009584:Nitrogen
keywords: CO(2) stress; Cell ultrastructure; Microalgae; Nuclear mutants; Salt stress