GSE107343
RNA-seq based transcriptional profiling of petroleum sludge-derived Pseudomonas aeruginosa ZS1 strain in response to alteration of growth conditions
We show that ZS1 in the medium supplemented with YE (YE-medium) produces more cell biomass but less rhamnolipid than it does in Glc-medium. To elucidate the transcriptional regulation of genes that are involved in biosynthesis of rhamnolipids and its precursors, RNA-seq-based transcriptional profiling of ZS1 cells in response to reciprocal change of YEand Glc-media is performed. Based on the assembly of ZS1 transcriptome using the reference PAO1 genome, we show that genes involved in energy metabolic pathways in ZS1 strain are highly transcribed in YE medium but not in Glc-medium, in agreement with their cell mass production. Similarly, transcription of quorum sensing systems genes lasI-lasR, rhlI-rhlR, and pqsH-mvfR are downregulated in Glc-medium. On the other hand, we show that two of the three enzymes RhlB and RhlC essential for rhamnolipid biosynthesis are transcriptionally upregulated, independent of quorum sensing signals. Notably, three of the four enzymes involved in dTDP-L-rhamnose, a precursor for the rhamnolipid biosynthesis, are downregulated in Glc except for RmlD that catalyzes the last reaction in the pathway. Together, our results indicate that increased rhamnolipid production in ZS1 cells is independent of quorum sensing signals. We propose that quorum sensing-independent rhamnolipid production in ZS1 Glc-culture is achieved by transcriptional re-programming of the minimum number of genes involved in rhamnolipid biosynthesis. Overall design: Examination of transcriptional profiling of ZS1 cells in response to reciprocal change of YEand Glc-medium.