N-acyl-L-homoserine lactone quorum sensing controls butanediol fermentation in Serratia plymuthica RVH1 and Serratia marcescens MG1

Abstract

Butanediol fermentation in two Serratia species is shown to be affected by N-acyl-L-homoserine lactone-dependent quorum sensing. Knockout of quorum-sensing signal production caused a shift towards enhanced acid production, resulting in early growth arrest, which was reversible by the addition of synthetic signal molecules.

FIG. 1.

Growth of S. plymuthica RVH1 (gray line) and its isogenic splI mutant with (diamonds) or without (black line) the addition of 10 μM 3-oxo-C₆-HSL in LB medium supplemented with 0.5% galactose.

FIG. 2.

Voges-Proskauer (top images, bottom row) and methyl red (top images, top row) assays and semiquantitative determination of amounts of acetoin (white bars), 2,3-butanediol (gray bars), and diacetyl (diagonally striped bars) for the S. plymuthica RVH1 wild type (left) and its isogenic splI mutant, isogenic splI mutant complemented with 10 μM 3-oxo-C₆-HSL, isogenic splR mutant, and isogenic splI splR double mutant. Amounts are expressed relative to the levels in RVH1 (100%). The experiment was performed in duplicate.