Global Metabolomics Reveals That Vibrio natriegens Enhances the Growth and Paramylon Synthesis of Euglena gracilis

Ying Ouyang; Shuyu Chen; Liqing Zhao; Yiting Song; Anping Lei; Jiayi He; Jiangxin Wang

doi:10.3389/fbioe.2021.652021

Global Metabolomics Reveals That Vibrio natriegens Enhances the Growth and Paramylon Synthesis of Euglena gracilis

Front Bioeng Biotechnol. 2021 Mar 31:9:652021. doi: 10.3389/fbioe.2021.652021. eCollection 2021.

Authors

Ying Ouyang^{1

2}, Shuyu Chen², Liqing Zhao², Yiting Song³, Anping Lei¹, Jiayi He^{1

4}, Jiangxin Wang^{1

4}

Affiliations

¹ Shenzhen Key Laboratory of Marine Bioresources and Eco-Environmental Science, Shenzhen Engineering Laboratory for Marine Algal Biotechnology, Guangdong Provincial Key Laboratory for Plant Epigenetics, College of Life Sciences and Oceanography, Shenzhen University, Shenzhen, China.
² College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, China.
³ Department of Microbiology, University of Illinois Urbana-Champaign, Champaign, IL, United States.
⁴ Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Provinces, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China.

Abstract

The microalga Euglena gracilis is utilized in the food, medicinal, and supplement industries. However, its mass production is currently limited by its low production efficiency and high risk of microbial contamination. In this study, physiological and biochemical parameters of E. gracilis co-cultivated with the bacteria Vibrio natriegens were investigated. A previous study reports the benefits of E. gracilis and V. natriegens co-cultivation; however, no bacterium growth and molecular mechanisms were further investigated. Our results show that this co-cultivation positively increased total chlorophyll, microalgal growth, dry weight, and storage sugar paramylon content of E. gracilis compared to the pure culture without V. natriegens. This analysis represents the first comprehensive metabolomic study of microalgae-bacterial co-cultivation, with 339 metabolites identified. This co-cultivation system was shown to have synergistic metabolic interactions between microalgal and bacterial cells, with a significant increase in methyl carbamate, ectoine, choline, methyl N-methylanthranilate, gentiatibetine, 4R-aminopentanoic acid, and glu-val compared to the cultivation of E. gracilis alone. Taken together, these results fill significant gaps in the current understanding of microalgae-bacteria co-cultivation systems and provide novel insights into potential improvements for mass production and industrial applications of E. gracilis.

Keywords: Euglena gracilis; Vibrio natriegens; co-cultivation; metabolomics; paramylon.