Response to starvation and microbial community composition in microbial fuel cells enriched on different electron donors

Abstract

Summary In microbial fuel cells ( MFC s), microorganisms generate electrical current by oxidizing organic compounds. MFC s operated with different electron donors harbour different microbial communities, and it is unknown how that affects their response to starvation. We analysed the microbial communities in acetate‐ and glucose‐fed MFC s and compared their responses to 10 days starvation periods. Each starvation period resulted in a 4.2 ± 1.4% reduction in electrical current in the acetate‐fed MFC s and a 10.8 ± 3.9% reduction in the glucose‐fed MFC s. When feed was resumed, the acetate‐fed MFC s recovered immediately, whereas the glucose‐fed MFC s required 1 day to recover. The acetate‐fed bioanodes were dominated by Desulfuromonas spp. converting acetate into electrical current. The glucose‐fed bioanodes were dominated by Trichococcus sp., functioning as a fermenter, and a member of Desulfuromonadales , using the fermentation products to generate electrical current. Suspended biomass and biofilm growing on non‐conductive regions within the MFC s had different community composition than the bioanodes. However, null models showed that homogenizing dispersal of microorganisms within the MFC s affected the community composition, and in the glucose‐fed MFC s, the Trichococcus sp. was abundant in all locations. The different responses to starvation can be explained by the more complex pathway requiring microbial interactions to convert glucose into electrical current.

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Identifiers

DOI

10.1111/1751-7915.13449

Journal

Microbial Biotechnology

Year

2019