近海柴油降解菌群的构建及其对柴油的降解特性

Construction of diesel fuel-degrading bacterial consortium from coastal waters and its characteristics on degradation of diesel fuel

摘要:

【目的】实施近海柴油污染的生物治理。【方法】以柴油为唯一碳源，从深圳港口海域富集筛选柴油降解菌；采用复配、正交试验等方式构建混合菌群；通过单因素试验研究环境因素对菌群降解柴油的影响；使用气相色谱-氢火焰检测器(GC-FID)分析降解前后柴油各组分的变化；通过生理生化试验和16S rRNA基因序列分析对菌株进行鉴定。【结果】获得了16株柴油降解菌，7 d内对柴油的降解率最高达40.8%；选择菌株C1-8、C2-10、C3-13构建了混合菌群CQ1，投加量分别为0.5%、2.0%和1.0%，CQ1对柴油去除率比单菌提高了10%以上；CQ1的最适环境条件为：温度30 °C、pH 7.6、摇床转速220 r/min、柴油浓度20 g/L，优化后9 d内对柴油去除率达60%以上；GC-FID结果显示，菌群CQ1可降解大部分C11?C27的正构烷烃，对C21?C27的烷烃降解可达100%。经鉴定，菌株C1-8、C2-10和C3-13分别为微杆菌(Microbacterium sp.)、剑菌(Ensifer sp.)和变异棒杆菌(Corynebacterium variabile)。【结论】CQ1在近海柴油污染的生物修复中具有良好的应用前景。

Abstract:

[Objective] For the purpose of control marine diesel pollution by biological treatment technology. [Methods] Diesel act as sole carbon source, using enrichment and screening methods to select diesel fuel-degrading bacteria from Shenzhen harbor area; bacterial consortium is constructed by mixing and orthogonal experiments; single-factor experimental is used to study the effect of environmental factors on diesel biodegradation by the consortium; using chromatography-flame ionization detection (GC-FID) to analyze the changes of diesel components before and after degradation, physiological, biochemical experiment and 16S rRNA gene sequence analysis are used to identify the strains. [Results] Sixteen diesel fuel-degrading bacteria were isolated and the highest degrading rates were up to 40.8% in 7 days. Bacteria consortium CQ1 was composed of C1-8, C2-10 and C3-13 strains, and the dosage was 0.5%, 2.0% and 1.0% respectively. Compared to the single strain, the degrading rate of CQ1 was increased by more than 10%. The best degrading effects would be up to 60% in 9 days under the optimum conditions that 30 °C, pH 7.6, shaking speed 220 r/min and diesel concentration 20 g/L. The result of GC-FID showed that most n-alkanes C11?C27 can be degraded by bacteria consortium CQ1 and the degradation rate of C21?C27 were up to 100%. In addition, the results showed that C1-8 belonged to Microbacterium sp., C2-10 belonged to Ensifer sp., C3-13 belonged to Corynebacterium variabile. [Conclusion] CQ1 has bright application prospects of bioremediation for offshore diesel pollution.