Copper isotope fractionation during surface adsorption and intracellular incorporation by bacteria

摘要: Abstract Copper isotopes may prove to be a useful tool for investigating bacteria–metal interactions recorded in natural waters, soils, and rocks. However, experimental data which attempt constrain Cu isotope fractionation biologic systems are limited unclear. In this study, we utilized (δ 65 Cu) investigate Cu–bacteria interactions, including surface adsorption intracellular incorporation. Experiments were conducted with individual representative species of Gram-positive ( Bacillus subtilis ) Gram-negative Escherichia coli bacteria, as well wild-type consortia microorganisms from several environments. Ph-dependent experiments live dead cells over the pH range 2.5–6. Surface onto bacterial resulted apparent separation factors (Δ solution–solid  = δ solution  − δ solid ranging +0.3‰ +1.4‰ B. +0.2‰ +2.6‰ E. . because heat-killed did not exhibit behavior, preference lighter by is probably related reversible adsorption, but instead metabolically-driven phenomenon. Adsorption yielded −0.69‰ likely reflects complexation organic acid functional group sites. For incorporation lab strains preferentially incorporated an Δ ∼+1.0‰ +4.4‰. Our results indicate that sequester regardless conditions. The mechanisms involved active cellular transport regulation, reduction Cu(II) Cu(I). Because similar machinery shared fungi, plants, higher organisms, influence biological processes on δ waters soils considerable.