Predictive microbiology was utilized to model Staphylococcus aureus （S. aureus） growth and staphylococcal enterotoxin A （SEA） production in milk in this study. The modifed logistic model, modifed Gompertz model an...Predictive microbiology was utilized to model Staphylococcus aureus （S. aureus） growth and staphylococcal enterotoxin A （SEA） production in milk in this study. The modifed logistic model, modifed Gompertz model and Baranyi model were applied to model growth data of S. aureus between 15℃ and 37℃. Model comparisons indicated that Baranyi model described the growth data more accurately than two others with a mean square error of 0.0129. Growth rates generated from Baranyi model matched the observed ones with a bias factor of 0.999 and an accuracy factor of 1.01, and ft a square root model with respect to temperature; other two modifed models both overestimated the observed ones. SEA amount began to be detected when the cell number reached106.4 cfu ？ mL-1, and showed the linear correlation with time. Besides, the rate of SEA production ftted an exponential relationship as a function of temperature. Predictions based on the study could be applied to indicate possible growth of S. aureus and prevent the occurrence of staphylococcal food poisoning.展开更多
该研究以一株对金黄色葡萄球菌(Staphylococcus aureus)具有拮抗作用的菌株tz-6为研究对象,通过形态学观察、生理生化试验及16S r DNA序列分析对其进行菌种鉴定,并考察其对金黄色葡萄球菌生长、β-半乳糖苷酶、脱氧核糖核酸(DNA)和蛋白...该研究以一株对金黄色葡萄球菌(Staphylococcus aureus)具有拮抗作用的菌株tz-6为研究对象,通过形态学观察、生理生化试验及16S r DNA序列分析对其进行菌种鉴定,并考察其对金黄色葡萄球菌生长、β-半乳糖苷酶、脱氧核糖核酸(DNA)和蛋白质泄漏程度、生物膜形成以及丙酮酸释放等的影响,探究其抑菌机制。结果表明,菌株tz-6被鉴定为链霉菌属(Streptomyces sp.),其发酵粗提物会能对金黄色葡萄球菌细胞膜和内膜结构产生破坏作用,增加细胞膜的通透性,导致酸性物质及β-半乳糖苷酶释放,增强了菌液上清的核酸和蛋白质含量,同时阻碍了金黄色葡萄球菌的机体能量和物质代谢。展开更多
基金Supported by"Academic Backbone"Project of Northeast Agricultural University(15XG26)the National High-level Talents Special Support Program of China
文摘Predictive microbiology was utilized to model Staphylococcus aureus （S. aureus） growth and staphylococcal enterotoxin A （SEA） production in milk in this study. The modifed logistic model, modifed Gompertz model and Baranyi model were applied to model growth data of S. aureus between 15℃ and 37℃. Model comparisons indicated that Baranyi model described the growth data more accurately than two others with a mean square error of 0.0129. Growth rates generated from Baranyi model matched the observed ones with a bias factor of 0.999 and an accuracy factor of 1.01, and ft a square root model with respect to temperature; other two modifed models both overestimated the observed ones. SEA amount began to be detected when the cell number reached106.4 cfu ？ mL-1, and showed the linear correlation with time. Besides, the rate of SEA production ftted an exponential relationship as a function of temperature. Predictions based on the study could be applied to indicate possible growth of S. aureus and prevent the occurrence of staphylococcal food poisoning.
文摘该研究以一株对金黄色葡萄球菌(Staphylococcus aureus)具有拮抗作用的菌株tz-6为研究对象,通过形态学观察、生理生化试验及16S r DNA序列分析对其进行菌种鉴定,并考察其对金黄色葡萄球菌生长、β-半乳糖苷酶、脱氧核糖核酸(DNA)和蛋白质泄漏程度、生物膜形成以及丙酮酸释放等的影响,探究其抑菌机制。结果表明,菌株tz-6被鉴定为链霉菌属(Streptomyces sp.),其发酵粗提物会能对金黄色葡萄球菌细胞膜和内膜结构产生破坏作用,增加细胞膜的通透性,导致酸性物质及β-半乳糖苷酶释放,增强了菌液上清的核酸和蛋白质含量,同时阻碍了金黄色葡萄球菌的机体能量和物质代谢。
