State Key Laboratory of Bioreactor Engineering, Shanghai Key Laboratory of Functional Materials Chemistry, School of Bioengineering, East China University of Science and Technology, Shanghai 200237, PR China.
Bioresour Technol. 2012 Nov;124:129-36. doi: 10.1016/j.biortech.2012.08.033. Epub 2012 Aug 24.
This study focused on acclimating a microbial enrichment to biodegrade benzene, toluene, ethylbenzene and xylenes (BTEX) in a wide range of salinity. The enrichment degraded 120 mg/L toluene within 5d in the presence of 2M NaCl or 150 mg/L toluene within 7d in the presence of 1-1.5M NaCl. PCR-DGGE (polymerase chain reaction-denatured gradient gel electrophoresis) profiles demonstrated the dominant species in the enrichments distributed between five main phyla: Gammaproteobacteria, Sphingobacteriia, Prolixibacter, Flavobacteriia and Firmicutes. The Marinobacter, Prolixibacter, Balneola, Zunongwangia, Halobacillus were the dominant genus. PCR detection of genotypes involved in bacterial BETX degradation revealed that the degradation pathways contained all the known initial oxidative attack of BTEX by monooxygenase and dioxygenase. And the subsequent ring fission was catalysed by catechol 1,2-dioxygenase and catechol 2,3-dioxygenase. Nuclear magnetic resonance (NMR) spectroscopy profiles showed that the bacterial consortium adjusted the osmotic pressure by ectoine and hydroxyectoine as compatible solutes to acclimate the different salinity conditions.
本研究致力于驯化微生物富集物，以在广泛的盐度范围内生物降解苯、甲苯、乙苯和二甲苯（BTEX）。在 2M NaCl 存在下，该富集物在 5d 内降解了 120mg/L 的甲苯，在 1-1.5M NaCl 存在下，在 7d 内降解了 150mg/L 的甲苯。PCR-DGGE（聚合酶链反应-变性梯度凝胶电泳）图谱表明，富集物中的优势物种分布在五个主要门之间：γ-变形菌门、鞘脂单胞菌门、普雷利西杆菌门、黄杆菌门和厚壁菌门。海洋杆菌属、普雷利西杆菌属、巴尔内奥拉属、紫单胞菌属、盐杆菌属是优势属。参与细菌 BETX 降解的基因型的 PCR 检测表明，降解途径包含了单加氧酶和双加氧酶对 BTEX 的所有已知初始氧化攻击。随后的环裂由儿茶酚 1,2-双加氧酶和儿茶酚 2,3-双加氧酶催化。核磁共振（NMR）光谱图谱表明，细菌共混物通过调节渗透压力适应不同的盐度条件。
