Membrane photobioreactor for biogas capture and conversion - Enhanced microbial interaction in biofilm

Baorui Zhang; Jianbo Liu; Chen Cai; Yan Zhou

doi:10.1016/j.biortech.2024.131999

Membrane photobioreactor for biogas capture and conversion - Enhanced microbial interaction in biofilm

Bioresour Technol. 2024 Dec 18:418:131999. doi: 10.1016/j.biortech.2024.131999. Online ahead of print.

Authors

Baorui Zhang¹, Jianbo Liu², Chen Cai³, Yan Zhou⁴

Affiliations

¹ Interdisciplinary Graduate Program, Nanyang Technological University, 61 Nanyang Drive, 637335, Singapore; Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore.
² School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
³ CAS Key Laboratory of Urban Pollutant Conversion, Department of Environmental Science and Engineering, University of Science and Technology of China, Hefei, China. Electronic address: chencai21@ustc.edu.cn.
⁴ Nanyang Environment & Water Research Institute, Nanyang Technological University, 1 Cleantech Loop, Singapore 637141, Singapore; School of Civil and Environmental Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore. Electronic address: ZhouYan@ntu.edu.sg.

PMID: 39706307
DOI: 10.1016/j.biortech.2024.131999

Abstract

The urgency to mitigate greenhouse gas emissions has driven interest in sustainable biogas utilization. This study investigates a 1 L enclosed membrane photobioreactor (MPBR) using a microalgae-methanotroph coculture for biogas capture. Operating with a hydraulic and solid retention time of 7 days and a biogas loading rate of 2.7 L /day, the introduction of gas membrane module increased CO₂-C and CH₄-C uptake rates by 12 % and 50 %, respectively. Biofilm formation on the membrane surface enhanced system performance, with imaging analyses revealing methanotroph predominantly located near the membrane surface and photosynthetic microorganisms distributed throughout. Metagenomic analysis showed shifts in key metabolic pathways, including increased abundance of soluble methane monooxygenase genes and enhanced vitamin B synthesis in the biofilm. These findings highlight the spatial organization and metabolic interactions in methanotroph-microalgae coculture system, providing insights into the role of membrane-induced biofilms in improving MPBR performance for sustainable biogas utilization.

Keywords: Carbon fixation; Methanotroph-Microalgae coculture system; Microalgae-Bacteria symbiosis.