响应面法研究温度、盐度、pH及磷酸盐、硝氮、氨氮对副溶血弧菌生长的影响

Study on the Effects of Temperature, Salinity, pH, Phosphate, Nitrate, and Ammonium on the Growth of Vibrio parahaemolyticus Using Response Surface Methodology

中文关键词: 副溶血弧菌  生长  理化因子  影响分析  响应面法

英文关键词: Vibrio parahaemolyticus  Growth  Physical and chemical factors  Impact analysis  Response surface methodology

中文摘要:

      副溶血弧菌(Vibrio parahaemolyticus，VP)在海洋环境中普遍存在，是能够引起人类中毒的重要食源性病原菌之一，研究其生长受环境因子的影响规律对科研和社会生活都具有重要意义。本研究采用响应面法研究温度、盐度、pH、磷酸盐、硝氮和氨氮对VP的生长影响，以探讨、评估这6种理化因子的综合作用结果。首先用Design-Expert软件中的Box Behnken中心组合原则设计三因素三水平响应面实验，再进行响应面分析，以培养基光密度(OD600 nm)值为生长状态参数，获得该菌的最佳培养参数：温度为34.5℃，盐度为3%，酸碱度pH为8.0。在此基础上，考察NaNO3、NH4Cl和Na3PO4对VP生长的影响并建立模型。回归方程决定系数R2=0.9217，校正系数R2=0.8211，回归模型F=9.16, P=0.004，表明该模型具有较好的准确性。实验所得实测值与模型演算理论值拟合良好，皆表明磷酸盐、硝氮和氨氮对VP的生长都具有抑制作用。

英文摘要:

      Vibrio parahaemolyticus (VP), which is ubiquitous in the marine environment, is one of the key foodborne pathogens affecting humans. It is thus of great significance for both scientific research and public safety that we understand how and what environmental factors affect its growth. To determine the functional relationship between a combination of environmental factors and VP growth, in this study the effects of temperature, salinity, pH, phosphate, nitrate, and ammonium on the growth of this kind of bacteria were investigated using response surface methodology (RSM). First, a Box-Behnken design was used to optimize the three critical internal factors of temperature, salinity and pH for this species, using optical density (OD600 nm) as a marker for the growth of VP. It was found that for these factors, the optimum parameters were 34.5℃, 3%, and 8.0, respectively. Based on these results, the combined effects of phosphate, nitrate, and ammonium on the growth of VP were then further studied with the same method to develop a response model. The coefficient of determination (R2) of the model equation was 0.9217, while the correction coefficient (R2) was 0.8211. The regression model had an F-value of 9.16, and was thus statistically significant (P=0.004). These results indicated that the model proposed herein had satisfactory accuracy. Results obtained from verified testing were also in good agreement with those obtained with the model. Clearly, phosphate, nitrate, and ammonium all exhibited negative effects on the growth of VP. These outcomes are beneficial to the culture of VP, and even to the establishment of early warning systems for marine environments and seafood safety.