基于响应面法的耐镉假单胞菌TCd-1培养条件优化

  目的  利用响应面法优化耐镉菌株假单胞菌Pseudomonas TCd-1的培养条件。  方法  以基础发酵培养条件为对照，菌株吸光度D(660)作为评价指标，利用单因素试验确定培养基组分的最佳碳源、氮源和无机盐种类，通过Plackett-Burman试验设计评价牛肉膏、酵母粉、氯化镁、培养温度、初始pH、接菌量、培养时间和转速8个因素对菌株生长的影响，进而确定显著影响因素，然后进行最陡爬坡试验获得显著影响因素的最优组合，结合Box-Behnken试验设计和响应面分析，优化假单胞菌TCd-1的培养条件。  结果  菌株培养基组分的最佳碳源、氮源和无机盐分别为牛肉膏、酵母粉和氯化镁；影响菌株生长的显著性因素为酵母粉、培养温度、初始pH；基于响应面法优化后的培养条件为:牛肉膏质量分数为0.5%，酵母粉1.0%，氯化镁0.5%，pH 6.3，温度33 ℃，接菌量1.25%，转速160 r·min?1，培养时间24 h。  结论  根据最佳条件, 进行重复试验得到优化后的菌液吸光度D(660)比对照提高了67.07%，与模型预测值相一致，表明优化后的条件显著促进了菌株的生长，达到预期目的。图1表6参26

Optimization of culture conditions of Cd-tolerant strain Pseudomonas TCd-1 based on response surface methodology

  Objective  This study aims to optimize the culture conditions of Cd-tolerant Pseudomonas TCd-1 based on response surface methodology.  Method  Taking the basic fermentation conditions as the control, and the absorbance D(660) value of the strain as the evaluation index, the single factor test was carried out to determine the best carbon source, nitrogen source, and inorganic salt species of the culture medium components. The Plackett-Burman test design was used to evaluate the influence of 8 factors on the growth of the strain, including beef extract, yeast powder, magnesium chloride, culture temperature, initial pH, inoculation quantity, culture time, and rotation speed. The best combination of significant factors was obtained by the steepest climbing test. The culture conditions of TCd-1 were optimized by combining the box Behnken design test and response surface analysis.  Result  The best carbon source, nitrogen source, and inorganic salt of the strain culture medium components were beef extract, yeast powder, and magnesium chloride. The significant factors affecting the growth of the strain were yeast powder, culture temperature, and initial pH. The optimized culture conditions based on response surface methodology included beef extract 0.5%, yeast powder 1.0%, magnesium chloride 0.5%, pH 6.3, temperature 33 ℃, inoculation rate 1.25%, rotation speed 160 r·min?1, and culture time 24 h.  Conclusion  According to the optimal conditions, the D(660) value of the optimized bacterial solution is 67.07% higher than that of the control after repeated experiments, which is consistent with the predicted value of the model, indicating that the optimized conditions could significantly promote the growth of the strain and achieve the desired goal.Ch, 1 fig. 6 tab. 26 ref.]