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论文类型：期刊论文

发表时间：2016-10-01

发表刊物：WATER RESEARCH

收录刊物：SCIE、EI、PubMed、Scopus

卷号：102

页面范围：475-484

ISSN号：0043-1354

关键字：Direct interspecies electron transfer (DIET); Syntrophic metabolism of propionate and/or butyrate; Up-flow anaerobic sludge blanket (UASB); Geobacter species

摘要：Direct interspecies electron transfer (DIET) has been considered as an alternative to interspecies H-2 transfer (IHT) for syntrophic metabolism, but the microorganisms capable of metabolizing the key intermediates, such as propionate and butyrate, via DIET have yet to be described. A strategy of culturing the enrichments with ethanol as a DIET substrate to stimulate the communities for the syntrophic metabolism of propionate and/or butyrate was proposed in this study. The results showed that the syntrophic propionate and/or butyrate degradation was significantly improved in the ethanol-stimulated reactor when propionate/butyrate was the sole carbon source. The conductivity of the ethanol stimulated enrichments was as 5 folds (for propionate)/76 folds (for butyrate) as that of the traditional enrichments (never ethanol fed). Microbial community analysis revealed that Geobacter species known to proceed DIET were only detected in the ethanol-stimulated enrichments. Together with the significant increase of Methanosaeta and Methanosarcina species in these enrichments, the potential DIET between Geobacter and Methanosaeta or Methanosarcina species might be established to improve the syntrophic propionate and/or butyrate degradation. Further experiments demonstrated that granular activated carbon (GAC) could improve the syntrophic metabolism of propionate and/or butyrate of the ethanol -stimulated enrichments, while almost no effects on the traditional enrichments. Also, the high H-2 partial pressure could inhibit the syntrophic propionate and/or butyrate degradation of the traditional enrichments, but its effect on that of the ethanol-stimulated enrichments was negligible. (C) 2016 Elsevier Ltd. All rights reserved.