Project description:Bacillus anthracis Sterne 34F2 cells were grown in the absence of and in the presence of different concentrations of paraquat and hydrogen peroxide. Additionally, a deletion mutant strain lacking the sodA1 gene was also assayed with and without the addition of different concentrations of paraquat.
Project description:The aim of this study was to investigate the transcriptional response of human intestinal cells (CaCo-2/HT29-MTX) towards exposure to Bacillus cereus enterotoxins. Differences between toxin concentrations and exposure times were also assessed.
Project description:Antibiotics have dose-dependent effects on exposed bacteria. The medicinal use of antibiotics relies on their growth-inhibitory activities at sufficient concentrations. At subinhibitory concentrations, exposure effects vary widely among different antibiotics and bacteria. Bacillus subtilis responds to bacteriostatic translation inhibitors by mobilizing a population of cells (MOB-Mobilized Bacillus) to spread across a surface. How B. subtilis regulates the antibiotic-induced mobilization is not known. In this study, we used chloramphenicol to identify regulatory functions that B. subtilis requires to coordinate cell mobilization following subinhibitory exposure. We measured changes in gene expression and metabolism and mapped the results to a network of regulatory proteins that direct the mobile response. Our data reveal that several transcriptional regulators coordinately control the reprogramming of metabolism to support mobilization. The network regulates changes in glycolysis, nucleotide metabolism, and amino acid metabolism that are signature features of the mobilized population. Among the hundreds of genes with changing expression, we identified two, pdhA and pucA, where the magnitudes of their changes in expression, and in the abundance of associated metabolites, reveal hallmark metabolic features of the mobilized population. Using reporters of pdhA and pucA expression, we visualized the separation of major branches of metabolism in different regions of the mobilized population. Our results reveal a regulated response to chloramphenicol exposure that enables a population of bacteria in different metabolic states to mount a coordinated mobile response.
Project description:Transcriptional profiling by array of Bacillus amyloliquefaciens FZB42 at log phase(OD600=1.0) and early stationary phase(OD600=3.0) after maize root exudate treatment of three concentrations(0.25mg/ml,0.50mg/ml,1.00mg/ml).
