Greenhouse gas emission and functional gene dynamics in plant microbial fuel cells with natural and salt-affected soils
Journal
Journal of Cleaner Production
Journal Volume
521
Start Page
146231
ISSN
0959-6526
Date Issued
2025-08-25
Author(s)
Abstract
As a novel green energy technology, plant microbial fuel cells (PMFCs) can convert solar energy into electricity via plants and microorganisms. However, the potential of PMFCs in mitigating greenhouse gas emissions, particularly methane and nitrous oxide, in salt-affected soils remains underexplored. The study investigates the capability of PMFCs to generate electricity and reduce greenhouse gas emissions in both natural and salt-affected soils. The shifts in functional microbial consortia and their correlation with methane and nitrous oxide emissions were assessed through the quantification of related functional genes. Closed circuit PMFCs in natural soil generated average voltages of 0.21 ± 0.07 V, compared to 0.06 ± 0.04 V in salt-affected soil. Digital PCR analysis revealed the abundance of methanogens in PMFCs in salt-affected soils was considerably lower than that in natural soils, and methane flux analysis confirmed significantly lower methane emissions in salt-affected soils (3.69 ± 0.65 − 13.08 ± 5.46 mg/m2/hr in natural soils vs. 0.01 ± 0.01 − 0.93 ± 0.63 mg/m2/hr in salt-affected soils). The methane flux and methanogen abundance of closed circuit PMFCs in salt-affected soils were lower than those in open circuit conditions, suggesting that bioelectrochemical processes could mitigate methane emissions in salt-affected soils. The abundances of nitrous oxide-related genes (norB, nosZ, nirK, and nirS) was similar in PMFCs in both types of soil, which was consistent with the insignificant difference in nitrous oxide flux observed between these two soil types. The microbial communities of PMFCs in the natural and salt-affected soils were different from the start, with divergence persisting throughout the operation of PMFC systems, indicating the presence of distinct microbial populations adapted to the unique conditions of each soil type. Overall, this research demonstrates the potential application of PMFCs in salt-affected soils and warrants further research for improvement of the system performance.
Subjects
Digital PCR
Functional gene
Methane
Nitrous oxide
Salt-affected soil
Publisher
Elsevier BV
Type
journal article