Acceleration of lactate-utilizing pathway for enhancing biohydrogen production by magnetite supplementation in Clostridium butyricum

• Published in: Bioresource technology 2022-09, Vol.359, p.127448-127448, Article 127448
• Main Authors: Kim, Do-Hyung, Yoon, Jeong-Jun, Kim, Sang-Hyoun, Park, Jeong-Hoon
• Format: Article
• Language: English
• Subjects: Biohydrogen; Clostridium species; Conductive material; Metabolic flux; Transcriptional analysis
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127448

[Display omitted] •Magnetite supplementation increased hydrogen production by 25.6%.•Cosupplementation of lactate and magnetite increased hydrogen production by 58.9%.•Enhanced hydrogen production was caused by acceleration of lactate utilization.•Magnetite upregulates the expression of key genes for hydrogen production.•Magnetite promotes electron-bifurcation by activating the etfAB complex. A conductive metal compound can be used as a catalyst for enhancing hydrogen production by dark fermentation. This study aimed to identify mechanisms of enhanced hydrogen production by magnetite supplementation. Experiments were performed with lactate and/or magnetite supplementation to confirm that the lactate-utilizing pathway is the key cause of enhanced hydrogen production. Also, ribonucleic acid sample was collected for monitoring gene regulation under each condition. Hydrogen production was significantly enhanced by approximately 25.6% and 58.9%, respectively, via magnetite alone and with lactate. Moreover, the expression of genes involved in hydrogen production, including pyruvate ferredoxin oxidoreductase, hydrogenase, and ferredoxin, via magnetite alone and with lactate was upregulated by 0.26, 0.71, and 3.50 and 1.06, 2.14, and 1.94 times, respectively.