群体感应抑制剂对海洋生态功能菌生物膜形成的影响

[目的]研究天然群体感应抑制剂(Quorum sensing inhibitors,QSI)分子对海洋生态功能菌生物膜形成的影响.[方法]以对污损生物幼虫附着具有诱导作用的海洋细菌为目标菌,通过在其生物膜的形成过程中添加天然群体感应抑制剂,研究其对目标菌成膜细菌数和浮游细菌数、生物膜形态以及生物膜表面胞外多糖含量的影响.[结果]呋喃酮和吡啶在50 mg/L时,对8株目标菌的成膜有显著的抑制作用,抑制率在80％左右,吲哚、青霉烷酸和香豆素在较高浓度800 mg/L才有比较好的抑制活性.生长抑制实验结果显示,同等浓度下,QSI分子对目标菌成膜的抑制活性明显高于其对浮游细菌生长的抑制活性.结果表明,QSI分子主要通过干扰目标菌群体感应系统以抑制生物膜的形成.[结论]研究证实QSI分子在海洋菌生物膜形成过程中具有一定的调控作用.通过添加QSI可能能够间接抑制由生物膜诱导的污损生物附着,从而以新的角度研制新型抗污损物质.

The influence of quorum sensing inhibitors against marine functional bacterial biofilm formation

[Objective] To study the influence of natural quorum sensing inhibitors (QSI) against marine functional bacterial biofilm formation. [Methods] Some marine bacterial strains, which could induce the larval settlement of fouling organism, were regarded as target bacteria. Through adding natural quorum sensing inhibitors into the target bacterial cultures during their biofilm formation process, the influence of QSI on the biofilm and planktonic bacteria quantity, biofilm morphology as well as the surface extracellular polysaccharide were studied. [Results] Furanone and pyridine significantly inhibited the biofilm formation of all target bacterial strains at the concentration of 50 mg/L, with the inhibition rate of about 80%. However, indole, penicillanic acid and coumarin exhibited good inhibitory activity only at higher concentrations of 800 mg/L. The results of growth inhibition experiment showed that the inhibitory activity of QSI molecules on target bacterial biofilm formation was much higher than them against planktonic bacteria growth at the same concentration, which indicated that the biofilm formation inhibitory effect of QSI molecules was mainly due to their interference on the quorum sensing system of target bacteria. [Conclusion] This study confirmed that QSI molecules may play an important regulatory role in marine bacterial biofilm formation process. The biofilm induced larval settlement of fouling organisms might be indirectly inhibited through the addition of QSI, which may lead to new anti-fouling substances from another point of view.