Probing Microbial Extracellular Respiration Ability Using Riboflavin

• Published in: Analytical chemistry (Washington) Vol. 92; no. 15; pp. 10606 - 10612
• Main Authors: Zhang, Feng, Wu, Jing-Hang, Yu, Han-Qing
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 04.08.2020
• Subjects: Analytical chemistry; Chemistry; Cytochromes; Electron transfer; Electron Transport; Extracellular Space - metabolism; Fluorescence; Fluorescent Dyes - metabolism; Geobacter - cytology; Geobacter - metabolism; In situ measurement; Metal oxides; Microorganisms; Riboflavin; Riboflavin - metabolism; Shewanella - cytology; Shewanella - metabolism
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/acs.analchem.0c01650

Electrochemically active bacteria (EAB) are capable of extracellular electron transfer (EET) to insoluble metal oxides, and thus play a great role in the fields of environment, energy, and geosciences. However, rapid and accurate quantification of the EET ability of EAB is still challenging. In this work, we develop a riboflavin-based fluorescence method for facile, accurate, and in situ measurement of the EET ability of EAB. This method is successfully used to quantify the single-cellular EET ability of Geobacter sulfurreducens DL-1 (60.29 ± 13.02 fA) and Shewanella oneidensis MR-1 (2.11 ± 0.47 fA), the two widely present EAB in the environment. It also enables quantitative identification of EET-related c-type cytochromes in the outer membrane of S. oneidensis MR-1. This method provides a useful tool to rapidly identify EAB in diverse environments and elucidate their electron transfer mechanisms.