Work

Carbon distribution and metabolism mechanism of a novel mixotrophic Chlorella in municipal wastewater

Year: 2025

Type: article

Abstract: Conventional wastewater treatment technologies primarily convert complex organic matter into dissolved inorganic carbon (DIC) and a more difficult gaseous state CO 2 . Most microalgae species can photosynthetically assimilate above inorganic carbon, but their heterotrophic metabolic processes often dominate in glucose-mediated mixotrophy. Herein, we investigated the carbon-fixing metabolic pathways of Chlorella sp. MIHQ61 in municipal wastewater containing complex carbon sources. The total carbon removal (73.0 %) peaked on the 6th day, and DIC removal exceeded 50.0 % as the carbon migrating amount from municipal wastewater into the microalgal cells peaked. The glucose and NaHCO 3 combination promoted both autotrophic and heterotrophic metabolism. Headspace CO 2 emission, enzyme activity and central carbon metabolism results implied heterotrophic metabolism occurred more actively in the early stage and autotrophic metabolism dominated late stage. Redefined mixotrophic carbon allocation by revealing time-dependent autotrophic/heterotrophic interplay. Carbon distribution and mixotrophic mechanism provided new thinking on how to utilize microalgae and wastewater resource.

Source: Bioresource Technology

DOI: 10.1016/j.biortech.2025.132562

Authors: Xiaoyan Wang, Yu Hong, Yuewen Zhang, Dezhi Sun

Institution: Beijing Forestry University

Language: English

Topic: Algal biology and biofuel production

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Clean water and sanitation, Responsible consumption and production, Climate action

Open Access status: hybrid

Estimated APC paid: $4,880