Insights into carbon utilization under mixotrophic conditions in Chlamydomonas

Yanbo Ma; Yuyong Hou; Weijie Wang; Meijie Cui; Zhile Guo; Tong Han; Zhiyong Liu; Nahui Hao; Fangjian Chen; Lei Zhao

doi:10.1016/j.biortech.2023.128788

Insights into carbon utilization under mixotrophic conditions in Chlamydomonas

Bioresour Technol. 2023 Apr:374:128788. doi: 10.1016/j.biortech.2023.128788. Epub 2023 Feb 22.

Authors

Yanbo Ma¹, Yuyong Hou², Weijie Wang³, Meijie Cui⁴, Zhile Guo¹, Tong Han⁴, Zhiyong Liu², Nahui Hao⁴, Fangjian Chen², Lei Zhao⁵

Affiliations

¹ College of Life Science, North China University of Science and Technology. Tangshan, China; Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
² Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China; National Center of Technology Innovation for Synthetic Biology, Tianjin, China.
³ College of Life Science, North China University of Science and Technology. Tangshan, China.
⁴ Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China.
⁵ Key Laboratory of Engineering Biology for Low-carbon Manufacturing, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, China; National Center of Technology Innovation for Synthetic Biology, Tianjin, China. Electronic address: zhaol@tib.cas.cn.

PMID: 36828225
DOI: 10.1016/j.biortech.2023.128788

Abstract

Mixotrophic microalgae cultivation with various carbon resources is considered as a strategy that could increase biomass. However, the mechanism of carbon utilization between inorganic carbon (IC) and organic carbon (OC) remains unknown. In this study, IC and OC consumption, chlorophyll fluorescence parameters, intracellular Nicotinamide adenine dinucleotide phosphate content and transcriptional changes in related genes were characterized. The results showed that IC was utilized preferentially, whereas 76% IC was consumed at 8 h. Subsequently, OC was the dominant carbon resource for fermentation. The cell density in the IC group was 100% higher than that in the group without IC at 24 h. Bicarbonate addition enhanced photosynthesis by dissipating less energy and generating more electrons and energy, which benefited OC assimilation. This finding was verified by qRT-PCR analysis. These results elucidate the carbon utilization mechanism under mixotrophic conditions, which provide clues for promoting microalgae growth by regulating carbon utilization.

Keywords: Carbon sequestration; Chlamydomonas; Mixotrophic cultivation; Sodium acetate; Sodium bicarbonate.

MeSH terms

Biomass
Carbon
Chlamydomonas* / genetics
Microalgae*
Photosynthesis

Substances

Carbon