title: Light attenuates lipid accumulation while enhancing cell proliferation and starch synthesis in the glucose-fed oleaginous microalga Chlorella zofingiensis.
abstract: The objective of this study was to investigate the effect of light on lipid and starch accumulation in the oleaginous green algae Chlorella zofingiensis supplemented with glucose. C. zofingiensis, when fed with 30 g/L glucose, synthesized lipids up to 0.531 g/g dry weight; while in the presence of light, the lipid content dropped down to 0.352 g/g dry weight. Lipid yield on glucose was 0.184 g/g glucose, 14% higher than that cultured with light. The light-mediated lipid reduction was accompanied by the down-regulation of fatty acid biosynthetic genes at the transcriptional level. Furthermore, light promoted cell proliferation, starch accumulation, and the starch yield based on glucose. Taken together, light may attenuate lipid accumulation, possibly through the inhibition of lipid biosynthetic pathway, leading to more carbon flux from glucose to starch. This study reveals the dual effects of light on the sugar-fed C. zofingiensis and provides valuable insights into the possible optimization of algal biomass and lipid production by manipulation of culture conditions.
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Tianpeng
authors.initials: T
authors.lastname: Chen
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Bingbing
authors.initials: B
authors.lastname: Guo
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Xiaonian
authors.initials: X
authors.lastname: Ma
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Peipei
authors.initials: P
authors.lastname: Sun
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
authors.affiliation: Institute for Food &Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
mesh_terms: D049109:Cell Proliferation / Q000187:drug effects* / Q000528:radiation effects*; D002478:Cells, Cultured; D002708:Chlorella / Q000187:drug effects / Q000254:growth & development / Q000378:metabolism* / Q000528:radiation effects; D005947:Glucose / Q000008:administration & dosage*; D008027:Light; D008055:Lipids / Q000032:analysis / Q000528:radiation effects*; D012333:RNA, Messenger / Q000235:genetics; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013213:Starch / Q000096:biosynthesis*; D013549:Sweetening Agents / Q000008:administration & dosage
chemical_list: D008055:Lipids; D012333:RNA, Messenger; D013549:Sweetening Agents; D013213:Starch; D005947:Glucose