青岛近海沉积物生物被膜中密度感应及密度感应淬灭细菌多样性

【背景】细菌密度感应(Quorum sensing,QS)是指细菌利用分泌的信号分子进行相互交流的现象,而密度感应淬灭(Quorumquenching,QQ)是指通过干扰信号分子的产生、释放、积累或应答从而阻抑密度感应通路。【目的】探究青岛近海沉积物生物被膜中密度感应和密度感应淬灭细菌的多样性。【方法】采用海水培养基2216E从青岛近海沉积物生物被膜中分离获取可培养细菌,采用平板交互划线和高通量筛选的方法分别筛选具有密度感应和密度感应淬灭的菌株。【结果】共分离获得83株共54种具有密度感应和密度感应淬灭的细菌,分属于四大细菌门类:变形菌门、拟杆菌门、厚壁菌门和放线菌门。其中,38株(45.8%)可以产生酰基高丝氨酸内酯(Acyl-homoserine lactone,AHL)类信号分子,它们分属于变形菌门(37株,15种)和拟杆菌门(1株,1种),优势属为弧菌属和鲁杰氏菌属;能够降解AHL类信号分子的有57株(68.7%),在变形菌门(41株,23种)、拟杆菌门(14株,10种)、厚壁菌门(5株,5种)以及放线菌门(1株,1种)中均有分布。【结论】在青岛近海沉积物生物被膜可培养细菌中,具有密度感应和密度感应淬灭现象的菌株具有很高的丰度和多样性,为后续生态学意义的研究与海洋微生物的开发提供了参考。

Diversity of quorum sensing and quorum quenching bacteria in sediment biofilm of Qingdao offshore

Background] Quorum sensing refers to the phenomenon that bacteria use secreted signal molecules to communicate with each other, while quorum quenching refers to inhibiting the quorum sensing pathway by interfering with the production, release, accumulation or response of signal molecules. Objective] To explore the diversity of quorum sensing and quorum quenching bacteria in sediment biofilm of Qingdao offshore. Methods] Culturable bacteria were isolated from the sediment biofilm of Qingdao offshore by marine agar 2216E. The bacteria with quorum sensing and quorum quenching activities were screened by plate interaction and high-throughput screening methods. Results] A total of 83 bacterial strains and 54 bacterial species were isolated, belonging to the four major phyla of bacteria: Proteobacteria, Bacteroidetes, Firmicutes and Actinobacteria. Among them, 38 strains (45.8%) produced acyl-homoserine lactones signal molecules (AHLs), belonging to Proteobacteria (37 strains, 15 species) and Bacteroidetes (1 strain, 1 species). The dominant bacteria belong to the genera Vibrio and Ruegeria. 57 strains (68.7%) can degrade AHLs, including Proteobacteria (41 strains, 23 species), Bacteroidetes (14 strains, 10 species), Firmicutes (5 strains, 5 species) and Actinobacteria (1 strain, 1 species), which showed high abundance and diversity. Conclusion] The results of this study indicate that among the bacterial isolates from sediments biofilm in Qingdao offshore, quorum sensing and quorum quenching bacteria showed a high abundance and diversity. It laid a foundation for further research and development.