美国加州理工学院生物与生物工程系Dianne K. Newman和美国海军研究实验室Leonard M. Tender研究组合作取得一项新突破。他们发现细胞外DNA（eDNA）通过铜绿假单胞菌生物膜中的花青素（PYO）促进高效的细胞外电子转移（EET）。这一研究成果发表在2020年8月6日出版的《细胞》杂志上。

他们显示吩嗪通过与铜绿假单胞菌生物膜中的eDNA相互作用介导有效的EET。 eDNA结合可促进在生物膜基质中保留PYO和吩嗪羧酰胺。在体外，不同的吩嗪可以在存在或缺失DNA的情况下交换电子，并且可以直接通过DNA参与氧化还原反应。在体内，生物膜eDNA还可以支持氧化还原活性嵌入剂之间的快速电子转移。

这些结果共同证明，PYO：eDNA相互作用以快速的EET支持高效的氧化还原循环，其速度快于生物膜中PYO的损失速度。

研究人员表示，细胞外电子穿梭的氧化还原循环，可以使缺乏直接接触电子受体或供体的多细胞细菌生物膜内的亚群代谢激活。这些穿梭物如何催化生物膜内的EET，而不会丢失到环境中，一直是一个长期存在的问题。

附：英文原文

Title: Extracellular DNA Promotes Efficient Extracellular Electron Transfer by Pyocyanin in Pseudomonas aeruginosa Biofilms

Author: Scott H. Saunders, Edmund C.M. Tse, Matthew D. Yates, Fernanda Jiménez Otero, Scott A. Trammell, Eric D.A. Stemp, Jacqueline K. Barton, Leonard M. Tender, Dianne K. Newman

Issue&Volume: 2020-08-06

Abstract: Redox cycling of extracellular electron shuttles can enable the metabolic activityof subpopulations within multicellular bacterial biofilms that lack direct accessto electron acceptors or donors. How these shuttles catalyze extracellular electrontransfer (EET) within biofilms without being lost to the environment has been a long-standingquestion. Here, we show that phenazines mediate efficient EET through interactionswith extracellular DNA (eDNA) in Pseudomonas aeruginosa biofilms. Retention of pyocyanin (PYO) and phenazine carboxamide in the biofilm matrixis facilitated by eDNA binding. In vitro, different phenazines can exchange electrons in the presence or absence of DNA andcan participate directly in redox reactions through DNA. In vivo, biofilm eDNA can also support rapid electron transfer between redox active intercalators.Together, these results establish that PYO:eDNA interactions support an efficientredox cycle with rapid EET that is faster than the rate of PYO loss from the biofilm.

DOI: 10.1016/j.cell.2020.07.006

Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30871-0