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Quantitative proteomic profiling reveals photosynthesis responsible for inoculum size dependent variation in Chlorella sorokiniana
Author(s) -
Ma Qian,
Wang Jiangxin,
Lu Shuhuan,
Lv Yajin,
Yuan Yingjin
Publication year - 2013
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.24762
Subject(s) - chlorella sorokiniana , photosynthesis , light intensity , biology , chlorella , photosynthetic efficiency , biodiesel production , abiotic stress , food science , abiotic component , algae , botany , biodiesel , biochemistry , ecology , gene , physics , optics , catalysis
High density cultivation is essential to industrial production of biodiesel from microalgae, which involves in variations of micro‐environment around individual cells, including light intensity, nutrition distribution, other abiotic stress and so on. To figure out the main limit factor in high inoculum cultivation, a quantitative proteomic analysis (iTRAQ‐on‐line 2‐D nano‐LC/MS) in a non‐model green microalga, Chlorella sorokiniana , under different inoculum sizes was conducted. The resulting high‐quality proteomic dataset consisted of 695 proteins. Using a cutoff of P < 0.05, 241 unique proteins with differential expression levels were identified between control and different inoculum sizes. Functional analysis showed that proteins participating in photosynthesis (light reaction) and Calvin cycle (carbon reaction pathway) had highest expression levels under inoculum size of 1 × 10 6 cells mL −1 , and lowest levels under 1 × 10 7 cells mL −1 . Canonical correlation analysis of the photosynthesis related proteins and metabolites biomarkers showed that a good correlation existed between them (canonical coefficient was 0.987), suggesting photosynthesis process greatly affected microalgae biodiesel productivity and quality. Proteomic study of C. sorokiniana under different illuminations was also conducted to confirm light intensity as a potential limit factor of high inoculum size. Nearly two thirds of proteins showed up‐regulation under the illumination of 70–110 µmol m −2 s −1 , compared to those of 40 µmol m −2 s −1 . This result suggested that by elegantly adjusting light conditions, high cell density cultivation and high biodiesel production might be achieved. Biotechnol. Bioeng. 2013; 110: 773–784. © 2012 Wiley Periodicals, Inc.