微生物种间直接电子传递研究进展

Research advances in direct interspecies electron transfer within microbes

一直以来氢气和甲酸被认为是微生物间电子传递的中间电子传递体。近年来的研究发现,微生物之间可以通过种间直接电子传递(DIET)来替代氢气/甲酸传递。DIET作为一种新发现的微生物间电子传递途径,其电子传递效率要高于传统的种间氢气/甲酸传递。DIET这一新发现改变了微生物互营生长代谢必须依赖氢气或甲酸等电子载体的传统认识,为今后研究微生物互营现象打开了新视角。虽然DIET研究取得了很大进展,但是目前对能够进行DIET的微生物种类、DIET机制及影响DIET的因素尚缺乏深入研究。本文首先概述了能形成DIET的微生物,然后重点分析了能够进行DIET的电子供体微生物胞外电子传递的机制和电子受体微生物直接利用胞外电子的分子机制,最后阐述了导电材料对DIET的影响,并提出了DIET今后的研究方向,旨在为DIET研究提供参考。

Hydrogen and formic acid have been considered as the intermediate electron transporters among microbes for a long time.In recent years,however,it has been found that direct interspecies electron transfer(DIET)might be an alternative beyond hydrogen/formic acid to transfer electron among microbes.As a new way of electron transfer among microbes,the electron transfer efficiency of DIET is higher than that of traditional hydrogen/formate transfer.The discovery of DIET has changed the traditional understanding that the growth and metabolism of microbial syntrophism must rely on electron carriers such as hydrogen or formic acid,and also has opened a new perspective for the study of microbial interaction.Although great progress has been made in the study of DIET,in-depth studies are still lacking on the microbes that can form co-culture via DIET,the mechanism of DIET,and the factors affecting DIET.In this review,we summarized the microbes that can form DIET,the mechanism underlying the extracellular electron transfer of microbe acted as electron donor in DIET,as well as the mechanism underlying the extracellular electron transfer of microbe acted as electron acceptor in DIET.The effects of conductive materials on DIET were elaborated,and several research directions for DIET were proposed,with the aim to mitigate performance degradation and facilitate research and development in this area.