The variation of microorganisms and organics during methane production from lignite under an electric field

The succession of microbial communities and intermediates during methane production was determined by pyrosequencing and GC-MS to investigate the mechanism of biomethanation enhancement from coal.

The maximum methane production at 1.2 V was significantly higher than that at 0 V. Bacterial flora have been changed as a result of the addition of an electric field, e.g., the abundance of Pseudomonas significantly increased to enhance the coal degradation which improved the methane yield by facilitating the electron transfer. The fungal structure was also found stabilized by the electric field when compared to the control after 7 days of cultivation. The predominance of Methanosarcina could also stimulate interspecies electron transfer. The GC-MS analysis revealed that the electric field can selectively promote the metabolism of refractory intermediates such as esters and aromatics during coal biodegradation.

The application of an electric field could enhance methane production from coal by changing the structure and succession of microbial communities, improving electron transfer, and enhancing the fermentation of intermediates during coal biodegradation.