Molecular mechanism of boosted hydrogen production by Thermoanaerobacterium thermosaccharolyticum with biochar revealed by transcriptome analysis

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 500; p. 156903
• Main Authors: Bu, Jie, Ju, Xue-Wen, Liang, Lu-Xin, Zhao, Qian-Zhu, Wei Tiong, Yong, Wu, Hai-Zhen, Wah Tong, Yen, Zhu, Ming-Jun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.11.2024
• Subjects: Biochar; Biohydrogen; Hydrogenase; Mechanism; Thermoanaerobacterium thermosaccharolyticum; Transcriptome; Hydrogenase; Thermoanaerobacterium thermosaccharolyticum; Biohydrogen; Biochar; Mechanism; Transcriptome
• ISSN: 1385-8947
• DOI: 10.1016/j.cej.2024.156903

[Display omitted] •Biochar significantly enhances hydrogen production, yield and immobilized biomass.•BC600 upregulates ech hydrogenase and accessory hyp genes for hydrogen production.•BC600 downregulates hnd hydrogenase genes involved in hydrogen consumption.•Changes in key gene expression are more pronounced in immobilized cells. Although numerous studies have reported the enhancement of hydrogen production by biochar in dark fermentation, the molecular mechanisms underlying this enhancement remain poorly understood. This study investigated the role of biochar in boosting hydrogen production by Thermoanaerobacterium thermosaccharolyticum MJ2. The results showed that BC600 addition led to a 290.7% increase in hydrogen production and a 67.1% improvement in hydrogen yield, with a significant increase in cell biomass, 74% of which was immobilized on biochar. Transcriptome analysis revealed the upregulation of genes coding for hydrogen-producing ech hydrogenases and the downregulation of hnd hydrogenase genes involved in hydrogen consumption. Additionally, gene expression related to cell immobilization, nitrogen fixation for hydrogen production were also enhanced, while genes associated with glycolysis showed an overall downregulation. For the key genes of interest, BC600 had a more profound effect on their expression levels in immobilized cells compared to suspended cells within the same system. This study provides valuable insights into how biochar regulates microbial metabolism and gene expression to enhance hydrogen production, aiding in the development of more effective biochar application strategies for biohydrogen production.