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Updated: Dec 23, 2025
15:19
Development of Sulfidogenic Sludge from Marine Sediments and Trichloroethylene Reduction in an Upflow Anaerobic Sludge Blanket Reactor
Published on: October 15, 2015
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Enhanced Microbial Chromate Reduction Using Hydrogen and Methane as Joint Electron Donors.
Chao He1, Baogang Zhang1, Wenyue Yan1
1School of Water Resources and Environment, MOE Key Laboratory of Groundwater Circulation and Environmental Evolution, China University of Geosciences (Beijing), Beijing, 100083, China.
Journal of Hazardous Materials
|April 25, 2020
Summary
Simultaneously supplying hydrogen and methane as electron donors significantly accelerates microbial chromate reduction compared to using either alone. This finding enhances understanding of bioremediation strategies for contaminated aquifers.
Area of Science:
- Environmental microbiology
- Bioremediation
- Geochemistry
Background:
- Aquifers often contain co-existing hydrogen and methane.
- Individual use of hydrogen or methane as electron donors for chromate bioreduction is established.
- The effect of simultaneous hydrogen and methane supply on microbial chromate reduction is largely unknown.
Purpose of the Study:
- To investigate the impact of simultaneous hydrogen and methane supply on microbial chromate reduction rates.
- To identify microbial communities and genes involved in chromate reduction with dual electron donors.
- To elucidate the mechanisms behind enhanced chromate reduction.
Main Methods:
- Microbial experiments with varying ratios of hydrogen and methane as electron donors.
- High-throughput 16S rRNA gene amplicon sequencing for microbial community analysis.
- Quantitative PCR to detect functional genes (hupL, mcrA, chrA).
- Biochemical assays for extracellular cytochrome c and intracellular NADH.
Main Results:
- Microbial chromate reduction rate was significantly accelerated with combined hydrogen and methane (1:1 ratio) compared to sole donors.
- The maximum reduction rate (4.70 ± 0.03 mg/L·d) was observed with the 1:1 ratio.
- Key microbial taxa (Spirochaetaceae, Delftia, Azonexus, Acetoanaerobium, Methanobacterium) and genes (hupL, mcrA, chrA) were identified.
- Increased extracellular cytochrome c and intracellular NADH indicated enhanced electron transfer.
Conclusions:
- Simultaneous supply of hydrogen and methane enhances microbial chromate reduction.
- A diverse microbial community, including specific reducers and methanogens, facilitates this process.
- Enhanced electron transfer mechanisms contribute to the accelerated bioreduction of chromate.
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