in-situ-characterization-shewanella-oneidensis-mr1-biofilms-salvi-tof

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

Bacterial biofilms are surface-associated communities that are vastly studied to understand their self-produced extracellular polymeric substances (EPS) ...

in-situ-characterization-boehmite-particles-water-using-liquid

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface ...

Pacific Northwest National Laboratory

The aggregation of syntrophic Geobacter metallireducens and Geobacter sulfurreducens is beneficial for enhancing direct interspecies electron transfer (DIET). Although DIET was suspected to occur on the microbial community surface, the surface chemical speciation of such cocultured communities remains unclear. In order to better understand surface interactions related to DIET, the authors characterized a series of samples associated with syntrophic G. metallireducens and G. sulfurreducens using surface sensitive time-of-flight secondary ion mass spectrometry (ToF-SIMS). Principal component analysis was used in spectral analysis. Our results show that the syntrophic Geobacter aggregates are significantly different from their planktonic cells, indicating a distinct chemical composition (i.e., amino acids, fatty acids, and lipids) and structure formed on their surface. Among these characteristic components, amino acid fragments dominated in the variance, suggesting the importance of proteins in the coculture. Additionally, the quorum sensing signal molecule N-butyryl-l-homoserine lactone was observed in cocultured Geobacter aggregates, implying its role in syntrophic growth and aggregate formation. Furthermore, the electron acceptor organism G. sulfurreducens was shown to be the dominant species in syntrophic communities that drove the syntrophic growth. These results demonstrate that unique chemical compositions distinguish syntrophic Geobacter aggregates from planktonic cells and suggest that ToF-SIMS may be a promising tool to understand the syntrophic mechanism and investigate interspecies electron transfer pathways in complex biofilms.

Characterization of syntrophic Geobacter communities using ToF-SIMS.

In the last decade, magnetic nanoparticles (MNPs), especially superparamagnetic iron oxide nanoparticles (SPIONs), have immensely promoted the advancement of diagnostics and theranostics in the biomedical field. The unique properties of the SPIONs-core and the functional gold (Au)-shell together (SPIONS/Au core/shell or CS) have a wide range of biomedical applications including, but not limited to, magnetic resonance imaging (MRI), dual modality MRI/computed tomography (CT), photo-induced and magnetic fluid hyperthermia (MFH), drug delivery, biosensors, and bio-separation. Researchers have made much effort to develop synthesis strategies for size control and surface modifications to achieve the desired properties of these CSs for applications in in vitro and in vivo studies. This review highlights recent developments in the synthesis and biomedical applications of SPIONs/Au CSs, including γ-Fe2O3/Au (maghemite), Fe3O4/Au (magnetite), and MFe2O4/Au (M = divalent metal ions) in the past seven years. More importantly, current trends of SPIONs/Au in relation to the biochemical industry are surveyed. Finally, we outline the developmental needs of SPIONs/Au from the perspective of material synthesis and their novel applications in disease diagnosis and treatment in the near future.

Rachel Komorek

Earth and Biological Sciences Directorate,
Earth & Biological Sciences Directorate

Pacific Northwest National Laboratory

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

Rachel Komorek

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Earth and Biological Sciences Directorate,Earth & Biological Sciences Directorate

Pacific Northwest National Laboratory

In Situ Characterization of Shewanella oneidensis MR1 Biofilms by SALVI and ToF-SIMS

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM

Earth and Biological Sciences Directorate,
Earth & Biological Sciences Directorate