title: Metabolic profiling reveals growth related FAME productivity and quality of Chlorella sorokiniana with different inoculum sizes.
abstract: Inoculum size strongly affects cell growth and lipid accumulation of microalgae, one of the most potential biodiesel feedstock, however, the metabolic mechanism(s) of the lipid biosynthesis upon inoculum size has not been fully explored yet. The effects of inoculum size on cell growth, lipid accumulation, and metabolic changes of a green microalga Chlorella sorokiniana were investigated. In our experimental range of inoculum size, the productivity and the cetane number (CN) of fatty acid methyl esters (FAME) increased with increasing initial cell density, and the inoculum of 1 × 10(7) cells mL(-1) processed much higher productivity (up to 2.02-fold) and CN (up to 1.19-fold) of the FAME than the others. A significant correlation between the metabolic profile and quantity and quality of lipid production was revealed by partial least-squares to latent structures (PLS) analysis, and 15 key metabolites were identified. Most of those metabolites were involved in the photosynthetically fixed carbon metabolism. Furthermore, light intensity as one of the vital limitation factors for the high inoculum size cultivation was evaluated by illumination assay and the results revealed that increasing light intensity could improve the polyunsaturated fatty acids composition and lipid accumulation of C. sorokiniana. The lipid productivity of the culture was improved by 71.21% with the light intensity of 110 µmol m(-2) s(-1), compared to that under the irradiance of 65 µmol m(-2) s(-1).
authors.affiliation: Key Laboratory of Systems Bioengineering, Ministry of Education and Department of Pharmaceutical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, PR China.
authors.forename: Shuhuan
authors.initials: S
authors.lastname: Lu
authors.forename: Jiangxin
authors.initials: J
authors.lastname: Wang
authors.forename: Yanhong
authors.initials: Y
authors.lastname: Niu
authors.forename: Jie
authors.initials: J
authors.lastname: Yang
authors.forename: Jian
authors.initials: J
authors.lastname: Zhou
authors.forename: Yingjin
authors.initials: Y
authors.lastname: Yuan
mesh_terms: D059827:Agricultural Inoculants / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D002708:Chlorella / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism*; D005227:Fatty Acids / Q000378:metabolism*; D050356:Lipid Metabolism; D055442:Metabolome
chemical_list: D005227:Fatty Acids