Effect of Acetic Acid on Biofilm Formation in <i>Paracidovorax citrulli</i>, Causal Agent of Bacterial Fruit Blotch

The unique tissue structure of pathogenic bacteria biofilm plays an important role in its pathogenicity and bactericide resistance. Inhibition or destruction of biofilm formation of pathogenic bacteria is of great significance for the control of plant bacterial diseases. In this study, Paracidovorax citrulli was inoculated into KB medium containing acetic acid, and after shaking at 28°C and 55 r/min for 48 h, it was found that the content of extracellular polysaccharide, extracellular protein and extracellular DNA (eDNA) decreased with the increase of acetic acid concentration, which resulted in the decrease of biofilm formation, it is not even possible to form biofilms on plastic slides. When the final concentration of acetic acid in the culture medium was greater than or equal to 0.5 mg/mL, there was no biofilm on the plastic slides. Therefore, the use of acetic acid as an inhibitor of P. citrulli has a good potential for control of bacterial fruit blotch.