Effects of pH, Temperature and Salinity on Extracellular Polymeric Substances of Pseudomonasaeruginosa Biofilm with N-(3-Oxooxtanoyl)-L-Homoserine Lactone Addition

Effects of pH, temperature and salinity on extracel lular polymeric substances (EPS) of Pseudomonasaeruginosa (P. aeruginosa ) biofilm with N-(3-oxooxtanoyl)-L-homoserine lactone (C8-oxo-HSL, one of the common quorum sensing (QS) signal in environment) addition were s tudied. C8-oxo-HSL addition increased polysaccharide concentration of biofilm EPS to promote the P. aeruginosa biofilm formation, but had little effects on protei n of EPS. C8-oxo-HSL addition should be carried out at pH 5-7 f or P. aeruginosa biofilm formation. The alkali-resistance of P. aeruginosa biofilm formation was stronger than that of acid-re sistance. Both polysaccharide and protein of EPS of P. aeruginosa biofilm reached the highest concentration at 20 ° C. C8-oxo-HSL addition promoted the inducement of QS, which would reduce the demand of NaCl for both mass propagation and EPS release for P. aeruginosa biofilm.