'The ability to detect specific functions of uncultured microbial cells in complex natural communities remains one of the most difficult tasks of environmental microbiology. Here we present respiration response imaging (RRI) as a novel fluorescence microscopy-based approach for the identification of microbial function, such as the ability to use C(1) ... More
Extracellular reduction of uranium via Geobacter conductive pili as a protective cellular mechanism.
AuthorsCologgi DL, Lampa-Pastirk S, Speers AM, Kelly SD, Reguera G,
JournalProc Natl Acad Sci U S A
PubMed ID21896750
'The in situ stimulation of Fe(III) oxide reduction by Geobacter bacteria leads to the concomitant precipitation of hexavalent uranium [U(VI)] from groundwater. Despite its promise for the bioremediation of uranium contaminants, the biological mechanism behind this reaction remains elusive. Because Fe(III) oxide reduction requires the expression of Geobacter''s conductive pili, ... More
Fullerene water suspension (nC60) exerts antibacterial effects via ROS-independent protein oxidation.
AuthorsLyon DY, Alvarez PJ,
JournalEnviron Sci Technol
PubMed ID19031913
Buckminsterfullerene (C60) can form water suspensions (nC60) that exert toxic effects. While reactive oxygen species (ROS) generation has been implicated as the mechanism for mammalian cytotoxicity, we propose that nC60 exerts ROS-independent oxidative stress in bacteria, with evidence of protein oxidation, changes in cell membrane potential, and interruption of cellular ... More
Oxygen consumption rates of bacteria under nutrient-limited conditions.
AuthorsRiedel TE, Berelson WM, Nealson KH, Finkel SE,
Journal
PubMed ID23770901
Many environments on Earth experience nutrient limitation and as a result have nongrowing or very slowly growing bacterial populations. To better understand bacterial respiration under environmentally relevant conditions, the effect of nutrient limitation on respiration rates of heterotrophic bacteria was measured. The oxygen consumption and population density of batch cultures ... More
In vitro susceptibility and cellular uptake for a new class of antimicrobial agents: dinuclear ruthenium(II) complexes.
AuthorsLi F, Feterl M, Mulyana Y, Warner JM, Collins JG, Keene FR,
JournalJ Antimicrob Chemother
PubMed ID22865383
To determine the in vitro susceptibility and cellular uptake for a series of dinuclear ruthenium(II) complexes [{Ru(phen)(2)}(2){µ-bb(n)}](4+) (Rubb(n)), and the mononuclear complexes [Ru(Me(4)phen)(3)](2+) and [Ru(phen)(2)(bb(7))](2+) against Staphylococcus aureus, methicillin-resistant S. aureus, Escherichia coli and Pseudomonas aeruginosa. The in vitro susceptibility was determined by MIC and MBC assays, and time-kill curve ... More
Iron homeostasis affects antibiotic-mediated cell death in Pseudomonas species.
AuthorsYeom J, Imlay JA, Park W,
JournalJ Biol Chem
PubMed ID20479007
Antibiotics can induce cell death via a variety of action modes, including the inhibition of transcription, ribosomal function, and cell wall biosynthesis. In this study, we demonstrated directly that iron availability is important to the action of antibiotics, and the ferric reductases of Pseudomonas putida and Pseudomonas aeruginosa could accelerate ... More
Real-time detection of actively metabolizing microbes by redox sensing as applied to methylotroph populations in Lake Washington.
Redox sensor green (RSG), a novel fluorescent dye from Invitrogen was employed as a tool for real-time detection of microbes metabolically active in situ, in combination with flow cytometry and cell sorting. Lake Washington sediment, an environment known for high rates of methane oxidation, was used as a model, and ... More
The response of Cupriavidus metallidurans CH34 to spaceflight in the international space station.
AuthorsLeys N, Baatout S, Rosier C, Dams A, s'Heeren C, Wattiez R, Mergeay M,
JournalAntonie Van Leeuwenhoek
PubMed ID19572210
The survival and behavior of Cupriavidus metallidurans strain CH34 were tested in space. In three spaceflight experiments, during three separate visits to the 'International Space Station' (ISS), strain CH34 was grown for 10-12 days at ambient temperature on mineral agar medium. Space- and earth-grown cells were compared post-flight by flow ... More