响应面优化大肠杆菌生物膜的培养条件

利用响应面法对大肠杆菌生物膜的培养条件进行优化。在单因素试验基础上,以细菌浓度、pH和培养时间为自变量,生物膜形成量为响应值,根据中心组合(Box-Benhnken)试验设计原理,研究各自变量及其交互作用对生物膜形成的影响,依据回归分析确定各培养条件的最优值,并通过激光共聚焦显微镜观察大肠杆菌生物膜的形成。结果表明,大肠杆菌生物膜的最佳培养条件为:LB培养基pH7.5,细菌接种量为1.2×10~7 cfu/mL,培养时间11.5 h。在该优化条件下,大肠杆菌生物膜的形成量OD_(600nm)可达0.60左右;通过激光共聚焦显微镜观察可见,此时形成大量的细菌聚集体,80%的视野已经被细菌覆盖,细菌活性很高,生物膜形成量达到高峰。

Optimization of Culture Conditions of Escherichia coli Biofilm by Response Surface Methodology

The culture conditions of Escherichia coli biofilm were optimized by response surface methodology. On the basis of single-factor tests, the bacterial concentration, pH value and culture time were taken as independent variables, and the amount of biofilm formation was used as the response value. According to the principle of Box-Benhnken design, the variables and their interactions were studied for biofilm. The influence of the formation was determined by regression analysis on the optimal values of each culture condition, and the formation of E.coli biofilms was observed by confocal laser microscopy. The results showed that the optimal conditions for the biofilm culture of E.coli were pH value in LB medium 7.5, bacterial inoculation 1.2×10⁷ cfu/mL, and culture time 11.5 h.Under this optimized condition, the biofilm formation amount of E.coli reached about 0.60 at OD_600nm. The confocal laser microscope showed a large number of bacterial aggregates, 80% of the field of vision had been covered by bacteria, the activity of bacteria was very high, and the amount of biofilm reached a peak.