Frontier Science Center for Synthetic Biology (Ministry of Education), Key Laboratory of Systems Bioengineering, and School of Chemical Engineering and Technology, Tianjin University, Tianjin, 300072, China.
Department of Biological Sciences and Technology, School of Environmental Studies, China University of Geoscience in Wuhan, Wuhan, Hubei, 430074, China.
Adv Sci (Weinh). 2024 Nov;11(41):e2403067. doi: 10.1002/advs.202403067. Epub 2024 Sep 5.
To investigate how cell elongation impacts extracellular electron transfer (EET) of electroactive microorganisms (EAMs), the division of model EAM Shewanella oneidensis (S. oneidensis) MR-1 is engineered by reducing the formation of cell divisome. Specially, by blocking the translation of division proteins via anti-sense RNAs or expressing division inhibitors, the cellular length and output power density are all increased. Electrophysiological and transcriptomic results synergistically reveal that the programmed cell elongation reinforces EET by enhancing NADH oxidation, inner-membrane quinone pool, and abundance of c-type cytochromes. Moreover, cell elongation enhances hydrophobicity due to decreased cell-surface polysaccharide, thus facilitates the initial surface adhesion stage during biofilm formation. The output current and power density all increase in positive correction with cellular length. However, inhibition of cell division reduces cell growth, which is then restored by quorum sensing-based dynamic regulation of cell growth and elongation phases. The QS-regulated elongated strain thus enables a cell length of 143.6 ± 40.3 µm (72.6-fold of that of S. oneidensis MR-1), which results in an output power density of 248.0 ± 10.6 mW m (3.41-fold of that of S. oneidensis MR-1) and exhibits superior potential for pollutant treatment. Engineering cellular length paves an innovate avenue for enhancing the EET of EAMs.
为了研究细胞伸长如何影响电活性微生物（EAMs）的细胞外电子转移（EET），通过减少细胞分裂体的形成来工程改造模型 EAM 希瓦氏菌（S. oneidensis）MR-1 的分裂。具体来说，通过反义 RNA 阻断分裂蛋白的翻译或表达分裂抑制剂，可以增加细胞长度和输出功率密度。电生理学和转录组学结果协同揭示，程序化的细胞伸长通过增强 NADH 氧化、内膜醌库和 c 型细胞色素的丰度来增强 EET。此外，由于细胞表面多糖的减少，细胞伸长增加了疏水性，从而有助于生物膜形成过程中的初始表面附着阶段。输出电流和功率密度都随细胞长度呈正相关增加。然而，细胞分裂的抑制会降低细胞生长，然后通过基于群体感应的细胞生长和伸长阶段的动态调节来恢复。QS 调节的伸长菌株因此能够实现 143.6 ± 40.3 µm 的细胞长度（S. oneidensis MR-1 的 72.6 倍），从而产生 248.0 ± 10.6 mW m 的输出功率密度（S. oneidensis MR-1 的 3.41 倍），并表现出优异的污染物处理潜力。工程化细胞长度为增强 EAMs 的 EET 开辟了一条新途径。
