Screening and Identification of a Strain with Quorum-Sensing Inhibitory Activity and Effect of the Crude Extracts on Virulence Factors of .

Quorum-sensing (QS) is involved in numerous physiological processes in bacteria, such as biofilm formation, sporulation, and virulence formation. Therefore, the search for new quorum-sensing inhibitors (QSI) is a promising strategy that opens up a new perspective for controlling QS-mediated bacterial pathogens. To explore new QSIs, a strain named sp. D67 with QS inhibitory activity was isolated from the soil of the arid zone around the Kumutag Desert in Xinjiang. Phylogenetic analyses demonstrated that strain D67 shared the highest similarity with NBRC 15402T (98.39%), which indicated it represented a potential novel species in the genus. The fermentation crude extracts of strain D67 can effectively reduce the violacein production produced by CV026 and the swarming and swimming abilities of . It also has significant inhibitory activity on the production of virulence factors such as biofilm, pyocyanin, and rhamnolipids of in a significant concentration-dependent manner, but not on protease activity. A total of 618 compounds were identified from the fermentation crude extracts of strain D67 by LC-MS, and 19 compounds with significant QS inhibitory activity were observed. Overall, the strain with QS inhibitory activity was screened from Kumutag Desert in Xinjiang for the first time, which provided a basis for further research and development of new QSI.