Li Cheng, Liu Chunjing, Li Rongzhen, Liu Yue, Xie Jianzhi, Li Bowen
College of Resources and Environmental Science, Hebei Agricultural University, Baoding 071001, China.
State Key Laboratory of North China Crop Improvement and Regulation, Baoding 071001, China.
Toxics. 2022 Sep 9;10(9):532. doi: 10.3390/toxics10090532.
Optimizing the culture conditions of DBP degradation by bacteria and investigating its biodegradation pathways have a great importance to develop effective PAEs pollution control strategies. In this study, we investigated the cultivation condition optimization, degradation kinetics, and degradation pathways of a newly isolated dibutyl phthalate (DBP) degradation strain, which was isolated from activated sludge and identified as DP-2 via morphological observation, biochemical identification, and 16S rDNA sequence analysis. The degradation conditions were optimized based on the results of single-factor experiments and response surface optimization experiments. The DBP degradation rate of DP-2 reached up to 85.86% when the inoculation amount was 17.14%, the DBP concentration was 9.81 mg·L and the NaCl concentration was 5 g·L. The GC-MS analysis results indicated that the intermediate metabolites of DP-2 mainly consisted of DMP, MBP, PA, and benzoic acid derivatives, which confirmed the degradation pathway from DBP to PA under aerobic pathway and then to BA under anaerobic pathway. In summary, DP-2 shows great potential for the degradation of DBP in contaminated soils.
优化细菌降解邻苯二甲酸二丁酯（DBP）的培养条件并研究其生物降解途径，对于制定有效的邻苯二甲酸酯类（PAEs）污染控制策略具有重要意义。在本研究中，我们对一株新分离的邻苯二甲酸二丁酯（DBP）降解菌株进行了培养条件优化、降解动力学及降解途径研究。该菌株从活性污泥中分离得到，经形态学观察、生化鉴定及16S rDNA序列分析鉴定为DP-2。基于单因素实验和响应面优化实验结果对降解条件进行了优化。当接种量为17.14%、DBP浓度为9.81 mg·L且NaCl浓度为5 g·L时，DP-2对DBP的降解率高达85.86%。气相色谱-质谱联用（GC-MS）分析结果表明，DP-2的中间代谢产物主要包括邻苯二甲酸二甲酯（DMP）、邻苯二甲酸单丁酯（MBP）、邻苯二甲酸（PA）和苯甲酸衍生物，证实了在好氧途径下DBP降解为PA，然后在厌氧途径下进一步降解为苯甲酸（BA）的降解途径。综上所述，DP-2在污染土壤中对DBP的降解具有巨大潜力。
