Effect of nano zero-valent iron (nZVI) on biohydrogen production in anaerobic fermentation of oil palm frond juice using Clostridium butyricum JKT37

Zhao

ACS Sustainable Chem. Eng.

et al. 2022

Biohydrogen is a clean and renewable energy, but the low yield caused by the lack of reducing power in cells greatly restricts the industrialization of biohydrogen production. Photobiohybrid systems (PBSs) can integrate the high light energy utilization efficiency of photocatalysts with the excellent catalytic performance of microorganisms. Here, gold nanoparticles were targeted into Clostridium butyricum as intracellular photosensitizers to construct a PBS that could efficiently produce biohydrogen under visible light, with the apparent quantum yield as high as 19.31%. Compared with the dark-fermented C. butyricum, the biohydrogen production of PBS increased by 88.74%. The mechanism of photoelectrons from Au NPs to C. butyricum was elucidated by the transcriptome. Compared with the darkfermented biohybrids, the expressions of biohydrogen generation-related enzymes, such as hydrogenase and pyruvate formate lyase genes, in the PBS were all upregulated more than 2 times. Furthermore, the genes of riboflavin synthase, electron transfer flavoprotein (ETF), and FAD-dependent oxidoreductase, which are closely related to electron transformation, were all significantly upregulated. The photoelectrons were transferred to the hydrogenase via ETF and FAD 2+ to enhance biohydrogen production, independent of pyruvate decomposition. This PBS provides theoretical guidance for constructing an efficient light-driven microbial manufacturing system.

Section: Resultsmentioning

confidence: 99%

Section: Synthesis Au Nps and Incorporation Of Au Nps Into C Butyricummentioning

confidence: 99%

Visible-Light-Driven Enhanced Biohydrogen Production by Photo-Biohybrid System Based on Photoelectron Transfer between Intracellular Photosensitizer Gold Nanoparticles and Clostridium butyricum

Zhao

ACS Sustainable Chem. Eng.

et al. 2022

Sustainable Energy Fuels

“…Nanoscale zerovalent metals are being reported for the biogas production of waste-activated sludge by inuencing the hydrolysis and acidication processes. 32,33 Nanoscale zerovalent metals help in eliminating the residual oxygen present in the system and also maintain the low oxidation-reduction potential (ORP), when used as an additive in the DFHP system and create a more favorable condition for hydrogen-producing microbes. 34 For instance, the addition of Fe 0 NPs to the DFHP system plays an important role in the balancing of undesired oxygen and improves the catalytic activity of highly oxygen-sensitive hydrogenases.…”

Section: Zerovalent Metalsmentioning

confidence: 99%

“…Reduction in the oxidation-reduction potential (ORP) of DFHP systems for balancing the DFHP metabolic system to improve hydrogen production is reported in the literature as dehydroarenes and ferredoxin enzyme activities are maintained at lower ORP levels. 32,42 Besides, the increased resistivity to the acidic environment of the DFHP system in the presence of zerovalent metallic nanoparticles is another perspective on their role in improved hydrogen productivity. 32 Although optimal concentration is an important aspect, which should be optimized with changes in operational conditions, more research should be oriented toward the recycling or cascade utilization of zerovalent metallic nanoparticles from the economic operation of the DFHP system.…”

Section: Zerovalent Metalsmentioning

confidence: 99%

“…32,42 Besides, the increased resistivity to the acidic environment of the DFHP system in the presence of zerovalent metallic nanoparticles is another perspective on their role in improved hydrogen productivity. 32 Although optimal concentration is an important aspect, which should be optimized with changes in operational conditions, more research should be oriented toward the recycling or cascade utilization of zerovalent metallic nanoparticles from the economic operation of the DFHP system.…”

Section: Zerovalent Metalsmentioning

confidence: 99%

See 1 more Smart Citation

Metals and metallic composites as emerging nanocatalysts for fermentative hydrogen production

Mishra

Johnravindar

Wong

et al. 2022

Water Environment Research

Effect of zero‐valent iron (ZVI) and biogas slurry reflux on methane production by anaerobic digestion of waste activated sludge

He,

Cui,

Chu

et al. 2024

This study aimed to improve anaerobic digestion (AD) efficiency through the addition of zero‐valent iron (ZVI) and biogas slurry. This paper demonstrated that methane production was most effectively promoted at a biogas slurry reflux ratio of 60%. The introduction of ZVI into anaerobic systems does not enhance its bioavailability. However, both biogas slurry reflux and the combination of ZVI with biogas slurry reflux increase the relative abundance of microorganisms involved in the direct interspecific electron transfer (DIET) process. Among them, the dominant microorganisms Methanosaeta, Methanobacterium, Methanobrevibacter, and Methanolinea accounted for over 60% of the total methanogenic archaea. The Tax4Fun function prediction results indicate that biogas slurry reflux and the combination of ZVI with biogas slurry reflux can increase the content of key enzymes in the acetotrophic and hydrotrophic methanogenesis pathways, thereby strengthening these pathways. The corrosion of ZVI promotes hydrogen production, and the biogas slurry reflux provided additional alkaline and anaerobic microorganisms for the anaerobic system. Their synergistic effect promoted the growth of hydrotrophic methanogens and improved the activities of various enzymes in the hydrolysis and acidification phases, enhanced the system's buffer capacity, and prevented secondary environmental pollution.Practitioner Points Optimal methane production was achieved at a biogas slurry reflux ratio of 60%. Biogas slurry reflux in anaerobic digestion substantially reduced discharge. ZVI addition in combination with biogas slurry reflux facilitates the DIET process.