Bacterial characterization using protein profiling in a microchip separations platform

A rapid microanalytical protein-based approach to bacterial characterization is presented. Chip gel electrophoresis (CGE) coupled with LIF detection was used to analyze lysates from different bacterial cell lines to obtain signature profiles of the soluble protein composition. The study includes Escherichia coli, Bacillus subtilis, and Bacillus anthracis (Delta Sterne strain) vegetative cells as well as endospores formed from the latter two species as model organisms to demonstrate the method. A unified protein preparation protocol was developed for both cell types to streamline the benchtop process and aid future automation. Cells and spores were lysed and proteins solubilized using a combination of thermal and chemical lysis methods. Reducing agents, necessary to solubilize spore proteins, were eliminated using a small-scale rapid size-exclusion chromatography step to eliminate interference with down-stream protein labeling. This approach was found to be compatible with nonspore cells (i.e., vegetative cells) as well, not adversely impacting the protein signatures. Data are presented demonstrating distinct CGE protein signatures for our model organisms, suggesting the potential for discrimination of organisms on the basis of empirical protein patterns. The goal of this work is to develop a fast and field-portable method for characterizing bacteria via their proteomes.     

Hydrothermal synthesis, crystal structure, thermal behavior, ferromagnetic resonance and ferrimagmetic behavior of (C4H12N2)1.5[Fe3(HAsO4)1.02(HPO4)0.98(AsO4)0.88(PO4)0.12F5]

(C₄H₁₂N₂)_1.5[Fe₃(HAsO₄)_1.02(HPO₄)_0.98(AsO₄)_0.88(PO₄)_0.12F₅] has been synthesized by using mild hydrothermal conditions under autogeneous pressure. The crystal structure was solved from X-ray single crystal data. The compound crystallizes in the monoclinic P2₁/c space group. The unit cell parameters are a=8.270(7), b=22.028(3), , β=99.79(2)° with Z=4. The crystal structure is formed from [Fe₃(HAsO₄)_1.02(HPO₄)_0.98(AsO₄)_0.88(PO₄)_0.12F₅]³⁻ sheets with the piperazinium cations located in the interlayer space, compensating the anionic charge and establishing hydrogen bonds. The IR and Raman spectroscopies confirm the existence of both the arsenate/hydrogenarsenate and phosphate/hydrogenphosphate oxoanions and the presence of the piperazinium dication. The reflectance diffuse spectrum is in good agreement with the existence of iron(III) high spin cations in slightly distorted octahedral geometry. The values of the Dq and Racah parameters are Dq=1005, B=1020 and . The ESR spectroscopy shows the presence of ferromagnetic resonance. The g-value shifts from 1.99(1) in the 300-15 K range to 3.11(1) at lower temperatures. Magnetic measurements indicate the presence of a ferrimagnetic behavior with the existence of a weak hysteresis loop at 5 K.     

ChemInform Abstract: Intercalation of Cu2+ in the HNiPO4×H2O Layered Phosphate: Study of the Structure,Spectroscopic, and Magnetic Properties of the Intercalated Derivative and the Related CuNi2(PO4)2 Compound.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.