Biochemical characterization and mercury methylation capacity of biofilms grown in media containing iron hydroxide or fumarate.

species are common in iron-rich environments and can contribute to formation of methylmercury (MeHg), a neurotoxic compound with high bioaccumulation potential formed as a result of bacterial and archaeal physiological activity. can utilize various electron acceptors for growth including iron hydroxides or fumarate. However, it remains poorly understood how the growth on these compounds affects physiological properties of bacterial cells in biofilms, including the capacity to produce MeHg.

The Combined Effect of Hg(II) Speciation, Thiol Metabolism, and Cell Physiology on Methylmercury Formation by .

The chemical and biological factors controlling microbial formation of methylmercury (MeHg) are widely studied separately, but the combined effects of these factors are largely unknown. We examined how the chemical speciation of divalent, inorganic mercury (Hg(II)), as controlled by low-molecular-mass thiols, and cell physiology govern MeHg formation by . We compared MeHg formation with and without addition of exogenous cysteine (Cys) to experimental assays with varying nutrient and bacterial metabolite concentrations.

Methylmercury formation in biofilms of .

Introduction: Mercury (Hg) is a major environmental pollutant that accumulates in biota predominantly in the form of methylmercury (MeHg). Surface-associated microbial communities (biofilms) represent an important source of MeHg in natural aquatic systems. In this work, we report MeHg formation in biofilms of the iron-reducing bacterium .

Chemical Functionalization of the Zinc Selenide Surface and Its Impact on GG Biofilms.

Bacteria grow on surfaces and form communities called biofilms. Bacterial adhesion and properties of the derived biofilms depend on, among others, the nature of the supporting substrate. Here, we report how the surface properties of the substrate affect the biofilm growth of probiotic GG (LGG).

spectroscopic analysis of GG flow on an abiotic surface reveals a role for nutrients in biofilm development.

In this work, infrared spectroscopy was used to monitor the changes in the biochemical composition of biofilms of the probiotic bacterium GG (LGG) in three nutritive media (10-fold diluted MRS, AOAC, and mTSB), and under flow conditions. Epifluorescence microscopy was used to observe the shape of LGG cells and their distribution on the surface. Spectroscopic fingerprints recorded as a function of time revealed a medium-dependent content of nucleic acids, phospholipids and polysaccharides in the biofilms.

Difficulties and flaws in performing accurate determinations of zeta potentials of metal nanoparticles in complex solutions-Four case studies.

The zeta potential (ZP) is a parameter commonly used to characterize metal nanoparticles (NPs) in solution. Such determinations are for example performed in nanotoxicology since the ZP influences e.g.