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

Lijie Zhou, Siqing Xia, Zhiqiang Zhang, Biao Ye, Xiaoyin Xu, Zaoli Gu, Xin Wang



Effects of pH, temperature and salinity on extracellular 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 studied. C8-oxo-HSL addition increased polysaccharide concentration of biofilm EPS to promote the P. aeruginosa biofilm formation, but had little effects on protein of EPS. C8-oxo-HSL addition should be carried out at pH 5-7 for P. aeruginosa biofilm formation. The alkali-resistance of P. aeruginosa biofilm formation was stronger than that of acid-resistance. 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.

Keywords: Extracellular polymeric substances; quorum sensing (QS); pH;temperature; salinity