Systematic metabolic tools reveal underlying mechanism of product biosynthesis in Chromochloris zofingiensis

Han Sun; Yuanyuan Ren; Yuwei Fan; Xue Lu; Weiyang Zhao; Feng Chen

doi:10.1016/j.biortech.2021.125406

Systematic metabolic tools reveal underlying mechanism of product biosynthesis in Chromochloris zofingiensis

Bioresour Technol. 2021 Oct:337:125406. doi: 10.1016/j.biortech.2021.125406. Epub 2021 Jun 14.

Authors

Han Sun¹, Yuanyuan Ren², Yuwei Fan³, Xue Lu⁴, Weiyang Zhao⁵, Feng Chen⁶

Affiliations

¹ College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China; Institute for Food & Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
² Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Shenzhen University, Shenzhen 518060, China; Institute for Food & Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
³ College of Food Science and Engineering, Ocean University of China, Qingdao 266003, China.
⁴ Institute for Food & Bioresource Engineering, College of Engineering, Peking University, Beijing, 100871, China.
⁵ Department of Food Science, Cornell University, Ithaca, NY 14853, USA.
⁶ Institute for Advanced Study, Shenzhen University, Shenzhen 518060, China; Shenzhen Key Laboratory of Marine Microbiome Engineering, Shenzhen University, Shenzhen 518060, China. Electronic address: sfchen@szu.edu.cn.

PMID: 34147773
DOI: 10.1016/j.biortech.2021.125406

Abstract

This study comprehensively explored underlying mechanism of fed-batch culture on product biosynthesis in Chromochloris zofingiensis by dynamic model, targeted metabolite determination, enzyme activity analysis, and ¹³C tracer-based metabolic flux analysis. Based on dynamic models of cell growth and product formation, exponential fed-batch culture and fed-batch culture based on pH changes were established to increase biomass concentration by 20.05-fold and 18.28-fold, respectively. Exponential fed-batch culture exhibited great potentials in biodiesel and protein productions from microalgae. Systematic metabolic tools revealed fed-batch culture limited photosynthetic efficiency by inhibiting photosystem and Rubisco activity, while strengthened respiratory action to provide more substances and energy for product biosynthesis. Fed-batch culture elevated biosynthetic capability for carotenoid and lipid by promoting related metabolic flux and contents of pyruvate and ace-CoA. Finally, economic analysis revealed biomass cost was decreased to 1.99 $/kg from 2.39 $/kg, suggesting fed-batch culture was a cost-effective strategy to improve economic viability of microalgal production.

Keywords: Carotenoid; Chromochloris zofingiensis; Fed-batch culture; Lipid; Protein.

MeSH terms

Batch Cell Culture Techniques
Biofuels
Biomass
Chlorophyceae*
Microalgae*

Substances

Biofuels