Role of ArcB/ArcA in the Regulation of Biofilm Formation in Escherichia coli in Conjunction with F1hD Expression
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Abstract
The two goals of this study were to identify the affect that arcB has on biofilm formation and to determine whether this was dependent on AckA. Acetyl phosphate is formed from acetyl-CoA during acetate metabolism and is degraded to acetate through the enzyme AckA. ArcB is the sensor kinase of the ArcB/ArcA two-component system involved in anaerobic metabolism [1]. Another important factor is the FlhD/FlhC global transcriptional regulator complex involved in regulating motility. The overall conclusion indicates acetyl phosphate has an effect on arcB only when both genes are nonfunctional as demonstrated by a lack of biofilm, increased motility, and increased flhD expression.
To test the hypothesis, several experiments were performed including scanning electron microscopy (SEM), growth curves, motility assays, and a ß-galactosidase assay measuring flhD expression. The tests were performed using a parent Escherichia coli K-12 strain (AJW678) and mutants in ackA, arcB, and an ackA arcB double mutant.