biostudies-literatureUnknown365(19)Moreno SPrograma de Apoyo a Proyectos de Investigación e Innovación Tecnológica—PAPIITResearch Council of NorwayConsejo Nacional de Ciencia y Tecnologia-CONACYTAzotobacter vinelandii produces differentiated cells, called cysts, surrounded by two alginate layers, which are necessary for their desiccation resistance. This alginate contains variable proportions of guluronate residues, resulting from the activity of seven extracytoplasmic epimerases, AlgE1-7. These enzymes are exported by a system secretion encoded by the eexDEF operon; mutants lacking the AlgE1-7 epimerases, the EexDEF or the RpoS sigma factor produce alginate, but are unable to form desiccation resistant cysts. Herein, we found that RpoS was required for full transcription of the algE1-7 and eexDEF genes. We found that the AlgE1-7 protein levels were diminished in the rpoS mutant strain. In addition, the alginate produced in the absence of RpoS was more viscous in the presence of pFEMS microbiology lettershttps://www.ebi.ac.uk/biostudies/studies/S-EPMC6140867biostudies-literatureRpoS controls the expression and the transport of the AlgE1-7 epimerases in Azotobacter vinelandii.PMC6140867255212221576207017Moreno SErtesvag HNunez CEspin GCocotl-Yanez MValla SfalseRpoS controls the expression and the transport of the AlgE1-7 epimerases in Azotobacter vinelandii.Azotobacter vinelandii produces differentiated cells, called cysts, surrounded by two alginate layers, which are necessary for their desiccation resistance. This alginate contains variable proportions of guluronate residues, resulting from the activity of seven extracytoplasmic epimerases, AlgE1-7. These enzymes are exported by a system secretion encoded by the eexDEF operon; mutants lacking the AlgE1-7 epimerases, the EexDEF or the RpoS sigma factor produce alginate, but are unable to form desiccation resistant cysts. Herein, we found that RpoS was required for full transcription of the algE1-7 and eexDEF genes. We found that the AlgE1-7 protein levels were diminished in the rpoS mutant strain. In addition, the alginate produced in the absence of RpoS was more viscous in the presence of p2018-01-01T00:00:00Z2018 Oct2025-04-04T09:27:04.282Z2019-03-26T23:57:16ZS-EPMC61408673016984910.1093/femsle/fny210