Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY, USA.
Department of Biomedical Engineering, City University of Hong Kong, Hong Kong, China.
Nat Chem. 2023 Oct;15(10):1400-1407. doi: 10.1038/s41557-023-01285-z. Epub 2023 Jul 27.
Microbe-semiconductor biohybrids, which integrate microbial enzymatic synthesis with the light-harvesting capabilities of inorganic semiconductors, have emerged as promising solar-to-chemical conversion systems. Improving the electron transport at the nano-bio interface and inside cells is important for boosting conversion efficiencies, yet the underlying mechanism is challenging to study by bulk measurements owing to the heterogeneities of both constituents. Here we develop a generalizable, quantitative multimodal microscopy platform that combines multi-channel optical imaging and photocurrent mapping to probe such biohybrids down to single- to sub-cell/particle levels. We uncover and differentiate the critical roles of different hydrogenases in the lithoautotrophic bacterium Ralstonia eutropha for bioplastic formation, discover this bacterium's surprisingly large nanoampere-level electron-uptake capability, and dissect the cross-membrane electron-transport pathways. This imaging platform, and the associated analytical framework, can uncover electron-transport mechanisms in various types of biohybrid, and potentially offers a means to use and engineer R. eutropha for efficient chemical production coupled with photocatalytic materials.
微生物-半导体生物杂合体将微生物酶合成与无机半导体的光收集能力相结合，已成为很有前途的太阳能-化学转化系统。提高纳米-生物界面和细胞内的电子传输对于提高转化效率很重要，但由于两种成分的异质性，通过批量测量来研究其潜在机制具有挑战性。在这里，我们开发了一种可推广的定量多模态显微镜平台，该平台结合了多通道光学成像和光电流映射技术，可在单细胞/颗粒水平下对这些生物杂合体进行探测。我们揭示并区分了岩盐单胞菌中不同氢化酶在自养生物塑料形成中的关键作用，发现了这种细菌具有出人意料的大纳安级别的电子摄取能力，并剖析了跨膜电子传输途径。该成像平台和相关分析框架可以揭示各种类型生物杂合体中的电子传输机制，并可能提供一种利用和工程化岩盐单胞菌进行高效化学生产并与光催化材料相结合的方法。
