Shewanella biofilm formation regulated by acyl-homoserine lactones and its application in UO22+ electrosorption.

Tingting LIU; Hong SHU; Qian LI; Zhao CUI; Guangyue LI; Ting LI; Yongdong WANG; Jing SUN

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Shewanella biofilm formation regulated by acyl-homoserine lactones and its application in UO₂²⁺ electrosorption.

Author: Tingting LIU ¹ ; Hong SHU ² ; Qian LI ² ; Zhao CUI ² ; Guangyue LI ¹ ; Ting LI ² ; Yongdong WANG ¹ ; Jing SUN ¹
Author Information

1. Key Discipline Laboratory for National Defense for Biotechnology in Uranium Mining and Hydrometallurgy, University of South China, Hengyang 421001, Hunan, China.
2. School of Resources Environment and Safety Engineering, University of South China, Hengyang 421001, Hunan, China.
Publication Type:Journal Article
Keywords: Shewanella oneidensis MR-1; acyl-homoserine lactones (AHLs); biofilm electrode; extracellular polymeric substances (EPS); quorum sensing; uranium
MeSH: Biofilms/drug effects*; Acyl-Butyrolactones/pharmacology*; Quorum Sensing/drug effects*; Uranium/metabolism*; Shewanella/metabolism*; Adsorption; Uranium Compounds/metabolism*; Wastewater/chemistry*; Biodegradation, Environmental; Extracellular Polymeric Substance Matrix/metabolism*
From: Chinese Journal of Biotechnology 2025;41(8):3081-3097
CountryChina
Language:Chinese
Abstract: Shewanella oneidensis MR-1, a Gram-negative bacterium with a significant role in the adsorption and reduction of uranium in wastewater and a quorum-sensing effect, can be used to remove uranium from wastewater. Exogenous signaling molecules (acyl-homoserine lactones, AHLs) can be added to induce the quorum sensing behavior for rapid biofilm formation, thereby improving the removal efficiency of this bacterium for uranium. Extracellular polymeric substances (EPS), as the significant components of biofilm, play a key role in biofilm formation. To investigate the quorum sensing behavior induced by AHLs, we systematically investigated the effects of AHLs on the EPS secretion and biofilm properties of S. oneidensis MR-1 by regulating parameters such as AHL species, concentration, addition time point, and contact time. The results showed that the addition of 10 μmol/L N-butyryl-l-homoserine lactone (C4-HSL) after 6 h of culture and continued incubation to reach the time point of 72 h significantly promoted the secretion of EPSs, in which the content of extracellular proteins and extracellular polysaccharides was increased by 15.2% and 28.2%, respectively, compared with that of the control group. The biofilm electrodes induced by signaling molecules showed superior properties, which were evidenced by an increase of exceeding 20 μm in biofilm thickness, an increase of 33.9% in the proportion of living cells, enhanced electroactivity, and an increase of 10.7% in the uranium removal rate. The biofilm electrode was confirmed to immobilize uranium in wastewater mainly by electrosorption, physicochemical adsorption, and electro-reduction through characterization means such as X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). This study provides a new technical idea for the efficient recovery of uranium in wastewater and enriches the theoretical system of quorum sensing regulation of electroactive biofilms.