Yunbin Jiang;Huan Deng;Hongyi Qin;Cheng Han;Wang Zhon

Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Geography Science, Nanjing Normal University, Nanjing 210023 (China);Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023 (China); Jiangsu Provincial Key Laboratory of Materials Cycling and Pollution Control, School of Geography Science, Nanjing Normal University, Nanjing 210023 (China

electrical signals;soil microbial activity;st;vegetated;red soils;mfc

Electrical signals generated by microbial fuel cells (MFCs) may potentially indicate overall soil microbial activity. This study aimed to validate whether a significant correlation existed between soil microbial activity and electrical signals in different soils. Re-vegetated red soils with four vegetation types and unplanted eroded red soil were collected and packed into MFCs. The voltage of the MFCs was recorded during operation. Electrical signals including start-up time (ST), peak voltage, and coulomb quantity were extracted from the voltage curves. Soil dehydrogenase activity (DHA) was determined as a reference method to verify the reliability of the electrical signals. After MFC operation, the anodic bacterial community was analyzed by Illumina sequencing based on the 16S rRNA gene. The results indicated that ST was significantly correlated with DHA, along with soil organic carbon content. The linear regression model described the optimal relationships for ST and DHA. Clostridium and Acinetobacter constituted the dominant genera on the anode of the MFCs. The results demonstrated that ST may indicate soil microbial activity in re-vegetated red soils.