title: [Low field nuclear magnetic resonance for rapid quantitation of microalgae lipid and its application in high throughput screening].
abstract: A rapid and accurate determination method of lipids in microalgae plays a significant role in an efficient breeding process for high-lipid production of microalgae. Using low field nuclear magnetic resonance (LF-NMR), we developed a direct quantitative method for cellular lipids in Chlorella protothecoides cells. The LF-NMR signal had a linear relationship with the lipid content in the microalgae cells for both dry cell samples and algal broth samples (R2 > 0.99). These results indicated that we could use this method for accurate determination of microalgal lipids. Although LF-NMR is a rapid and easy lipid determination method in comparison to conventional methods, low efficiency would limit its application in high throughput screening. Therefore, we developed a novel combined high throughput screening method for high-lipid content mutants of C. protothecoides. Namely, we initially applied Nile red staining method for semi-quantification of lipid in the pre-screening process, and following with LF-NMR method for accurate lipid determination in re-screening process. Finally, we adopted this novel screening method in the breeding process of high-lipid content heterotrophic cells of C. protothecoides. From 3 098 mutated strains 108 high-lipid content strains were selected through pre-screening process, and then 9 mutants with high-lipid production were obtained in the re-screening process. In a consequence, with heterotrophical cultivation of 168 h, the lipid concentration could reach 5 g/L, and the highest lipid content exceeded 20% (W/W), which was almost two-fold to that of the wild strain. All these results demonstrated that the novel breeding process was reliable and feasible for improving the screening efficiency.
authors.forename: Tingting
authors.initials: T
authors.lastname: Liu
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
authors.forename: Zejian
authors.initials: Z
authors.lastname: Wang
authors.forename: Yingping
authors.initials: Y
authors.lastname: Zhuang
authors.forename: Ju
authors.initials: J
authors.lastname: Chu
authors.forename: Meijin
authors.initials: M
authors.lastname: Guoi
mesh_terms: D000460:Chlorophyta / Q000737:chemistry*; D052836:Heterotrophic Processes; D057166:High-Throughput Screening Assays; D008055:Lipids / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D058086:Microalgae / Q000737:chemistry; D013194:Staining and Labeling
chemical_list: D008055:Lipids