Study on chemical structure and mechanism of soil-phase electron mediator enhancing dechlorination activity of anaerobic microorganisms

固相胡敏素是土壤和沉积物中不溶于任何pH条件的胡敏物质的一部分，被发现作为厌氧财团还原脱氯五氯酚的外部电子介体。从同一来源提取的腐殖酸不支持五氯酚脱氯。通过红外光谱、核磁共振、电子自旋共振、循环伏安等分析，推测胡敏素的氧化还原反应中心为醌结构或铁-有机酸螯合物。有人建议，一种新的Dehalabelsp.，需要还原型胡敏素作为电子供体和五氯苯酚作为电子受体用于有机卤化物呼吸，存在于富集的聚生体中。认为电子从胡敏素直接转移到微生物细胞。

Solid-phase humin, a fraction of humic substances in soil and sediment which is not soluble in any pH condition, was found to function as external electron mediator for the anaerobic consortium reductively-dechlorinating pentachlorophenol. The humic acids extracted from the same source did not support the pentachlorophenol dechlorination. The redox-reacting centers of humin were suggested to be quinone structure or iron-organic acid chelating complex, based on the analyses using FT-IR, NMR, ESR, cyclic voltammetry. It was suggested that a novel Dehalobacter sp., requiring reduced-form humin as electron donor and pentachlorophenol as electron acceptor for the organohalide respiration, was present in the enriched consortium. It was considered that the electrons transfer from humin to microbial cells directly.