活的非可培养状态细菌的培养和复苏条件的研究

Study on the culture and recovery conditions of viabile but nonculturable bacteria

中文关键词:  大肠杆菌  金黄色葡萄球菌  活的非可培养状态  诱导  复苏

英文关键词:Escherichia coli  Staphylococcus aureus  viabile but nonculturable  induction  recovery

中文摘要:

      目的 研究食品常用的消杀条件对大肠杆菌和金黄色葡萄球菌进入活的非可培养状态(viabile but nonculturable, VBNC)的诱导, 并探讨高温诱导的VBNC菌的复苏条件。方法 将对数生长期的大肠杆菌、金黄色葡萄球菌通过温度、盐度以及不同浓度的山梨酸钾处理进行诱导; 对高温条件诱导的VBNC菌液添加维生素类物质, 研究复苏VBNC菌的条件。结果 大肠杆菌在?20℃培养可形成VBNC菌, 在温度超过65℃, 水浴30 min时存在VBNC菌; NaCl浓度大于15%环境下培养15ｄ可诱导VBNC菌的形成; 山梨酸钾浓度高于0.15%即可诱导大肠杆菌进入VBNC; 金黄色葡萄球菌在相同条件下诱导菌落数变化缓慢, 未出现VBNC菌。复苏研究中, 添加0.10‰~0.18‰范围的维生素C或0.252%的泛酸或0.06‰生物素可使VBNC的大肠杆菌复苏; VBNC的金黄色葡萄球菌复苏则需要添加0.20‰~0.25‰范围的维生素C或0.248%的泛酸或0.06‰生物素。结论 食品常用的消杀条件均有形成VBNC菌的可能, VBNC状态下的大肠杆菌和金黄色葡萄球菌在添加适量维生素类物质后可恢复培养能力。本研究有望为企业对食品的消杀处理以及检测、储藏运输等条件改善提供科学依据。

英文摘要:

      Objective To study the induction of Escherichia coli and Staphylococcus aureus into viabile but nonculturable (VBNC) by commonly used food sterilization conditions, and explore the recovery conditions of high temperature-induced VBNC bacteria. Methods Escherichia coli and Staphylococcus aureus in logarithmic growth phase induced by temperature, salinity and different concentrations of potassium sorbate. Vitamins were added to the VBNC bacteria solution induced by high temperature to study the conditions for revival of VBNC bacteria. Results VBNC bacteria could be formed when Escherichia coli was cultured at ?20℃ and when the temperature exceeds 65℃ in a water bath for 30 min, the formation of VBNC bacteria could be induced by culturing for 15 days under the environment of NaCl concentration higher than 15%. It could be induced into VBNC by potassium sorbate concentration higher than 0.15%. Staphylococcus aureus induced a slow change in the number of colonies under the same conditions, and no VBNC bacteria appeared. In the resuscitation study, adding vitamin C in the range of 0.10‰?0.18‰ or 0.252% pantothenic acid or 0.06‰ biotin could revive Escherichia coli of VBNC state. The recovery of Staphylococcus aureus of VBNC state required the addition of vitamin C in the range of 0.20‰?0.25‰ or 0.248% pantothenic acid or 0.06‰ biotin. Conclusion Commonly used food sterilization conditions may form VBNC bacteria and Escherichia coli and Staphylococcus aureus in VBNC state can recover their cultivation ability after adding proper amount of vitamins. This research is expected to provide a scientific basis for the improvement of conditions such as food disinfection, detection, storage and transportation in enterprises.