Association of uranyl with the cell wall of Pseudomonas fluorescens inhibits metabolism

Abstract

Abstract-Citric acid is found along with uranyl in the subsurface of former nuclear facilities because of its use as a decontamination agent in the nuclear industry. Citrate's metal chelating properties affect the mobility of uranyl in the subsurface and consequently, citrate biodegradation may significantly impact uranyl fate and transport. Under the non-growth conditions considered, low (micromolar) uranyl concentrations inhibit the biodegradation of citrate by Pseudomonas fluorescens, a common subsurface denitrifying bacterium. Additionally, uranyl is found readily associated with the cell envelope of P. fluorescens. The observed inhibition appears to be linked to the binding of uranyl to the cell surface and is reversible by desorbing cell-bound uranyl. This study establishes a link between uranyl association with the cell surface and the observed inhibitory effect of uranyl on cell metabolism.

Uranium redox transition pathways in acetate-amended sediments

“…4) would provide a source of high-affinity U(IV)-binding phosphate sites (52). Phosphate is also released from cell lysis and can precipitate with uranium (14,53). The intimate association of biomass and mackinawite (Fig.…”

Mechanisms of uranium mineralization by the yeast Saccharomyces cerevisiae

“…Soares et al (2002) reported that S. cerevisiae NCNY 1190 releases P when it is exposed to Cd, Cu, and Pb. This release is attributed to uranium or heavy-metal toxicity (Soares et al, 2002;Bencheikh-Latmani and Leckie, 2003). Heavy metals induce lesions of the cell membrane of S. cerevisiae (Joho et al, 1984;Ohsumi et al, 1988), which may cause the cell to rupture.…”

A spectroscopic study on U(VI) biomineralization in cultivated Pseudomonas fluorescens biofilms isolated from granitic aquifers

“…However, no study is known concerning metaautunite formation due to uranium interaction with P. fluorescens strains. To our knowledge, only a few studies provided uranium sorption experiments using P. fluorescens strains (Krueger et al 1993;Bencheikh-Latmani and Leckie 2003;Francis et al 2004;Lütke et al 2012). These studies showed that the strain mainly accumulates uranium on the cell surface, where uranium is bound via protonated phosphoryl and carboxylic sites.…”

“…Krueger et al (1993) showed that the strain mainly accumulates uranium on the cell surface. In Bencheikh-Latmani and Leckie (2003), most of the uranyl is also associated with the outside of the cell. Similar results have been obtained by Francis et al (2004), where P. fluorescens was found to accumulate uranium in the periplasm along its plasma and outer membranes as fine-grained, platy uranium-crystals.…”