Vanillin Resistance Induced by BssS Overexpression in Escherichia coli
Overexpression of a biofilm formation regulator gene bssS confered the vanillin-resistant phenotype Van<sup>r </sup>to planktonic Escherichia coli cells. The MG1655P<sub>L-tac</sub>-bssS strain started growing in liquid aerated LB medium with 2 g/L vanillin after a lag phase of 17 +2 h, whereas the original MG1655 strain did not grow under these conditions. The role of aldehyde reductase YqhD, a vanillin-degrading enzyme, in Van<sup>r </sup>phenotype formation has been assessed. However, the Van<sup>r</sup> character of the MG1655P<sub>L-tac</sub>-bssS strain primarily depended on autoinducer-2 (AI-2), which formed in E. coli cells with an intact luxS gene. We supposed that BssS acts together with AI-2 to induce vanillin resistance determined by changes in the expression of a range of genes.