Pseudomonas putida QTH3对五氯硝基苯的降解特性

Degradation Characteristics of Pseudomonas putida QTH3 to Penatchioorniortbenzene

[目的]明确五氯硝基苯降解菌Pseudomonas putida QTH3的降解条件及降解特性。[方法]选择温度、pH值、底物初始浓度和接种菌量进行单因素试验,筛选温度、pH值和接种菌量3个因素进行最陡爬坡试验,获得最大响应区域,通过Box-Behnken试验设计3因素3水平的响应面试验,对其降解条件进行优化,在优化条件下测定了菌株QTH3降解五氯硝基苯的能力及其生长量。[结果]最适降解条件为温度28.48℃,pH值7.43,接种菌量1.63 g/L。优化后的培养条件降解率提高了19.17%,菌株QTH3在7 d后对五氯硝基苯的降解率为58.35%,菌株QTH3的生长量逐步增加。[结论]菌株QTH3能够利用五氯硝苯基作为唯一碳源和能源生长,可用于五氯硝基苯的生物修复。

[Aims]To explicit the degradation characteristics and degradation condition of Pseudomonas putida QTH3 to PCNB.[Methods]Single factor tests were conducted based on four factors of temperature,pH,substrate concentration and biomass amount of inoculums.The steepest ascent experiment was used to approach the optimal response region with three important factors of temperature,pH and biomass amount of inoculums.Response surface experiments designed by Box-Behnken with 3 factors and 3 levels were conducted to optimize the degradation conditions.Degradation of PCNB by strain QTH3 and bacterial growth were determined under optimum conditions.[Results]The optimal conditions of temperature 28.48℃,pH 7.43,and biomass amount of inoculums 1.63 g/L were obtained.The degradation rate of strain QTH3 to PCNB was increased by 19.17%under optimum conditions.The degradation rate of strain QTH3 to PCNB was 58.35%within 7 days.PCNB degradation was associated with a concomitant increase in cell density of strain QTH3.[Conclusions]Strain QTH3 could utilize PCNB as a sole carbon and energy source for growth,and potentially be employed in bioremediation of PCNB.