RNPP-type quorum sensing regulates solvent formation and sporulation inClostridium acetobutylicum [article]

Ann-Kathrin Kotte, Oliver Severn, Zak Bean, Katrin Schwarz, Nigel P Minton, Klaus Winzer
2017 bioRxiv   pre-print
The strictly anaerobic bacteriumClostridium acetobutylicumis well known for its ability to convert sugars into acids and solvents, most notably the potential biofuel butanol. However, the regulation of its fermentation metabolism, in particular the shift from acid to solvent production, remains poorly understood. The aim of this study was to investigate whether cell-cell communication plays a role in controlling the timing of this shift or the extent of solvent formation. Analysis of the
more » ... leC. acetobutylicumgenome sequences revealed the presence of eight putative RNPP-type quorum sensing systems, here designatedqssAtoqssH, each consisting of RNPP-type regulator gene followed by a small open reading frame encoding a putative signalling peptide precursor. The identified regulator and signal peptide precursor genes were designatedqsrAtoqsrHandqspAtoqspH, respectively. Triplicate mutants were generated for each system inC. acetobutylicumATCC 824 and screened for phenotypic changes. Endospores counts after 7 days were only affected in theqsrG-deficient strains, whereas solvent formation was affected in all mutants with the exception of theqsrD-deficient strains. TheqsrBmutants were of particular interest as they showed increased solvent formation during early solventogenesis. Overexpression ofqsrBconsiderably reduced solvent and endospore formation, suggesting that it acts as a repressor. Addition of short synthetic peptides representing internal fragments of QspB counteracted QsrB-mediated repression and restored both solvent production and sporulation. Together, these findings support the hypothesis that QssB is a functional quorum sensing system involved in the regulation of early solventogenesis and sporulation.
doi:10.1101/106666 fatcat:zi6od5ainnha5i73qho5xatks4