为了评估在硝酸钠存在的食品环境中金黄色葡萄球菌生物被膜的污染风险,研究了硝酸钠对金黄色葡萄球菌生物被膜形成的影响,并初步研究了其抑制机理.结果表明,在1.25 mmol/L~10 mmol/L的食品安全浓度下,硝酸钠即能抑制生物被膜的形成;当硝酸钠浓度为10 mmol/L时,生物被膜生物量减少了73.90%,生物被膜活性降低了92.56%.在生物被膜培养物中,硝酸钠生成了亚硝酸钠;在起始硝酸钠浓度为10 mmol/L培养基中,最终培养物中的亚硝酸钠浓度为5 mmol/L.食品安全浓度的硝酸钠对不同来源的食源性金黄色葡萄球菌菌株的生物被膜形成有普遍的抑制作用,抑制效果因菌株而异.此外,在较高浓度下,硝酸钠对生物被膜形成的抑制效果更好,当硝酸钠添加浓度为640 mmol/L时,基本检测不到活菌数.因此,硝酸钠有潜力成为食品环境中金黄色葡萄球菌生物被膜的杀菌剂与去除剂.%In order to evaluate the contamination risk of Staphylococcus aureus biofilm in the food environment containing with sodium nitrate, the effect of sodium nitrate on biofilm formation was studied and the inhibition mechanism was explored. The results showed that sodium nitrate could inhibit biofilm formation in the range of 1.25 mmol/L-10 mmol/L. The biofilm biomass and biofilm viability were reduced 73.90 % and 92.56 % by adding 10 mmol/L sodium nitrate, respectively. Sodium nitrate was converted into sodium nitrite in biofilm cul-tures. Medium contained 10 mmol/L sodium nitrategenerated 5 mmol/L sodium nitrite in the final culture. Sodi-um nitrate in the concentration for food safety could generally inhibite biofilm formation of different food-borne S. aureus strains, and the inhibition effect was different with strains .Moreover, efficacy of sodium nitrate in in-hibiting biofilm formation was more obvious in higher concentration. 640 mmol/L sodium nitrate could inhibite biofilm formation completely. Therefore, sodium nitrate has great potential to be used as a bactericide and re-moving agent for S.aureus biofilm.
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