Coupling attached cultivation with CO2 absorption-microalgae conversion system for efficient bio-integrated carbon capture and utilization

Yaoqi Hou; Zhan Hu; Pengcheng Li; Dantong Wang; Danqing Chen; Yi Wang; Yizhen Wei; Yutaka Kitamura; Chunfeng Song

doi:10.1016/j.biortech.2025.132933

Coupling attached cultivation with CO₂ absorption-microalgae conversion system for efficient bio-integrated carbon capture and utilization

Bioresour Technol. 2025 Jul 1:435:132933. doi: 10.1016/j.biortech.2025.132933. Online ahead of print.

Authors

Yaoqi Hou¹, Zhan Hu¹, Pengcheng Li¹, Dantong Wang¹, Danqing Chen¹, Yi Wang¹, Yizhen Wei¹, Yutaka Kitamura², Chunfeng Song³

Affiliations

¹ Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, PR China.
² Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1, Tennodai, Tsukuba, Ibaraki 305-8572, Japan.
³ Tianjin Key Laboratory of Indoor Air Environmental Quality Control, School of Environmental Science and Engineering, Tianjin University, 92 Weijin Road, Nankai District, Tianjin, PR China. Electronic address: chunfeng.song@tju.edu.cn.

PMID: 40609766
DOI: 10.1016/j.biortech.2025.132933

Abstract

An integrated photobioreactor for simultaneous carbon capture and utilization was developed by coupling non-immersed attached cultivation with CO₂ absorption-microalgae conversion (CAMC) system. Polyester porous cotton, mixed cellulose ester (MCE) membrane and Chlorella L166 were screened as the optimal candidates. Compared with traditional suspended cultivation, attached cultivation significantly increased biomass yield and carbon fixation capacity by 326.6% and 371.2%, respectively. Carbon flow predominantly shifts toward lipid synthesis during bioconversion. Transcriptomics revealed that adaptive CO₂ concentrating mechanism (CCM) such as C₄-dicarboxylic acid cycle and crassulacean acid metabolism (CAM) pathways might be partially activated by attached cultivation for carbon fixation. Differentially expressed genes (DEGs) related to C₄ and CAM pathways, such as pckA, ppc, ppdK, MDH2, GOT2 and GPT were significantly up-regulated. This study demonstrated efficient bio-integrated carbon capture and utilization through attached cultivation, enhancing bicarbonate assimilation and direct CO₂ capture from the atmosphere, while enabling cost-effective conversion in algae-based biorefineries.

Keywords: Bicarbonate; CO(2) concentrating mechanism; Carbon fixation; Photobioreactor; Transcriptomics.