Project description:In this study we focused on understanding the effect of over expression of recombinant protective antigen (rPA) on the Bacillus anthracis metabolism and genes expression with the purpose of improving the production of this recombinant toxin in particular and recombinant proteins in general. To achieve this goal controlled growth of the B. anthracis ames strain transformed with pYS5 (PA producer) plasmid encoding protective antigen and the corresponding empty vector pSW4 (non-producer) were performed and protein production, bacterial growth characteristics and gene transcription pattern were analyzed. Controlled condition batch runs were performed for both strains and samples from early log (OD 3), log (OD 10) and late log (OD 16) phase were used for gene expression profiling. We found that most of the genes belonging to transport, TCA, glycolysis, PPP and amino acid biosynthesis were up-regulated in the lag phase samples which help the cell coping with the increased requirements of nutrient and energy for rPA expression. These pathways are down-regulated in the log and latelog phase as cellular stress response onsets, which is reflected in the decreased specific growth rate.
Project description:Investigation of whole genome expression level changes in Bacillus anthracis Sterne deltaClpX mutant compared to the wild-type strain after growth in nutrient rich media. The deltaClpX mutant used in this study is described in McGillivray et al. 2009. ClpX Protease Contributes to Antimicrobial Peptide Resistance and Virulence Phenotypes of Bacillus anthracis. Journal of Innate Immunity 1(5): 494-506.
Project description:AtxA, the master virulence regulator of Bacillus anthracis, regulates the expression of three toxins that are required for the pathogenicity of Bacillus anthracis. Recent transcriptome analyses also showed that AtxA affects a large number of genes on both chromosome and plasmid, suggesting its role as a global regulator. Its mechanism of gene regulation nor binding target in vivo was, however, not well understood. In this work, we conducted ChIP-seq for cataloging binding sites of AtxA in vivo and Cappable-seq for catalogging the transcription start sites on the B. anthracis genome. For detected regulons, single knockout strains were constructed and RNA-seq was conducted for each strain.
Project description:The aim of the study was to carry out a CGH study utilizing a set of 39 diverse Bacillus isolates. Thirty four B. cereus and five B. anthracis strains and isolates were chosen so as to represent different lineages based on previous characterizations, including MLEE and MLST (Helgason, Okstad et al. 2000; Helgason, Tourasse et al. 2004). They represent the spectrum of B. cereus phenotypic diversity by including soil, dairy and periodontal isolates in addition to virulent B. anthracis strains.