Project description:We show for soil bacterium Enterobacter soli LF7 (synonym Enterobacter asburiae LF7a) that possession of a iac (indole 3-acetic acid catabolic) gene cluster is causatively linked to the ability to utilize the plant hormone indole 3-acetic acid (IAA) as a carbon and energy source. Genome-wide transcriptional profiling by mRNA sequencing revealed that these iac genes chromosomally arranged as iacHABICDEFG and coding for the transformation of IAA to catechol, were the most highly induced (>29-fold) among the relatively few (<1%) differentially expressed genes in response to IAA. Also highly induced and immediately downstream of the iac cluster were genes for a Major Facilitator Superfamily protein (mfs) and enzymes of the β-ketoadipate pathway (pcaIJD-catBCA), which channels catechol into central metabolism. This entire iacHABICDEFG-mfs-pcaIJD-catBCA gene set was constitutively expressed in a iacR deletion mutant, confirming the role of iacR, annotated as coding for a MarR-type regulator and located upstream of iacH, as a repressor of iac gene expression. The research described here was funded from grants #2010-03544 and #2013-02075 awarded to JHJL by the United States Department of Agriculture (USDA) National Institute of Food and Agriculture (NIFA) Agriculture and Food Research Initiative (AFRI)
Project description:Helicobacter cinaedi is an emerging bacterial pathogen of immunosuppressed individuals. The species is traditionally thought to require an H2-enhanced microaerobic atmosphere for growth, although it can proliferate under aerobic conditions when co-cultured with epithelial monolayers or supplemented with certain metabolites (notably, L-lactate). The goal of this experiment was to assess the global transcription changes that occur in the H. cinaedi type strain (ATCC BAA-847) under various media and atmospheric conditions. These include bacterial monoculture, as well as co-culture with Caco-2 intestinal epithelial cells. In total, Illumina mRNA-seq (stranded, paired-end) was performed on H. cinaedi grown under 9 in vitro culture conditions (4-5 biologic replicates per condition).
