(四川农业大学 食品学院, 四川 雅安 625014)
(College of Food Science, Sichuan Agricultural University, Yaan 625014,China)
为研究丁香酚对解淀粉芽孢杆菌DY1a生物膜的抑制作用及成膜早期界面黏附聚集能力的影响,分析了不同质量浓度的丁香酚对生物膜形成、生物膜表面微观结构、膜内活菌数及生物膜基质多糖和蛋白质含量的影响,并评价其对成熟生物膜的清除能力,通过细菌运动能力实验、细胞表面疏水性、细胞表面Zeta电位及细胞自聚集能力,综合分析丁香酚对生物膜形成早期界面黏附聚集能力的影响。结果表明:丁香酚对解淀粉芽孢杆菌的最低生物膜抑制质量浓度(MBIC)为1.500mg/mL,MBIC的丁香酚对成熟生物膜清除率为28.85%。添加1/2 MBIC、1/4 MBIC的丁香酚培养基气液界面形成的生物膜较为单薄,表面较为光滑平整,生物膜内活菌数显著降低。丁香酚对腐败菌泳动能力抑制率为22.16%~100.00%,对丛集能力的抑制率为43.86%~97.50%,使细胞表面疏水性、细胞表面负Zeta电位和自聚集率均降低。此外,丁香酚显著抑制了腐败菌胞外多糖和蛋白质合成。丁香酚对芽孢杆菌生物膜的抑制作用主要是通过抑制细菌运动能力,降低细胞表面的疏水性、自聚集性,从而干扰早期菌体在成膜界面上的黏附能力,并通过抑制胞外聚合物组分的合成分泌延迟生物膜的形成和成熟。丁香酚可作为抑制腐败解淀粉芽孢杆菌气液界面生物膜形成的潜在抗生物膜剂。
In order to evaluate the inhibitory effect of eugenol on the biofilm of Bacillus amyloliquefaciens DY1a and the effect of eugenol on the adhesion and aggregation ability of the interface in the early stage of biofilm formation, the effects of eugenol at different mass concentrations on the formation of biofilms, the surface microstructure of biofilms, the number of viable bacteria in biofilms and the content of polysaccharide and protein in biofilm matrix were analyzed, and the scavenging ability of mature biofilms was evaluated. The effect of eugenol on the adhesion and aggregation ability of biofilms in the early stage of biofilm formation was comprehensively analyzed by bacterial motility experiment, cell surface hydrophobicity, cell surface Zeta potential and cell self-aggregation ability. The results showed that the minimum biofilm inhibitory concentration (MBIC) of eugenol against B. amyloliquefaciens was 1.500mg/mL, and the eradication rate of eugenol against mature biofilm was 28.85%. The biofilm formed at the air-liquid interface of eugenol medium supplemented with 1/2 MBIC and 1/4 MBIC was thinner and smoother, and the number of viable bacteria in the biofilm was significantly reduced. Moreover, eugenol was capable of suppressing bacterial swimming (22.16% to 100.00%), swarming motility (43.86% to 97.50%). And cell surface hydrophobicity, negative cell surface Zeta charge, and auto-aggregation were also decreased. In addition, eugenol significantly inhibited exopolysaccharides and protein synthesis of bacteria. Therefore, the antibiofilm mechanism of eugenol against B. amyloliquefaciens DY1a was associated with inhibitory of bacterial motility, changes of cell surface hydrophobicity and auto-aggregation, thus interfering with the adhesion ability of early bacteria at the film forming interface, and inhibiting the synthesis and secretion of extracellular polymeric substance components to delay the growth and maturation of biofilm. In conclusion, eugenol could be used as a potential antibiofilm agent for control biofilm formation of B. amyloliquefaciens at the air-liquid interface.