Department of Life Sciences, National Central University, No. 300, Jhing-da Rd., Jhongli City, Taoyuan, 32001, Taiwan.
Graduate School of Biotechnology and Bioengineering, Yuan Ze University, No. 135, Yuantung Rd., Jhongli City, Taoyuan, 32003, Taiwan.
J Hazard Mater. 2018 May 5;349:79-90. doi: 10.1016/j.jhazmat.2018.01.039. Epub 2018 Feb 6.
Citrobacter sp. has been shown to degrade 2,4,6-trinitrotoluene (TNT). However, the mechanism of its TNT biodegradation is poorly understood. An integrated proteome and transcriptome analysis was performed for investigating the differential genes and differential proteins in bacterial growth at the onset of experiments and after 12 h treatment with TNT. With the RNA sequencing, we found a total of 3792 transcripts and 569 differentially expressed genes (≥2 fold, P < 0.05) by. Genes for amino acid transport, cellular metabolism and stress-shock proteins were up-regulated, while carbohydrate transport and metabolism were down-regulated. A total of 42 protein spots (≥1.5 fold, P < 0.05) showed differential expression on two-dimensional gel electrophoresis and these proteins were identified by mass spectrometry. The most prominent proteins up-regulated were involved in energy production and conversion, amino acid transport and metabolism, posttranslational modification, protein turnover and chaperones. Proteins involved in carbohydrate transport and metabolism were down-regulated. Most notably, we observed that nemA encoding N-ethylmaleimide reductase was the most up-regulated gene involved in TNT degradation, and further proved that it can transform TNT to 4-amino-2,6-dinitrotoluene (4-ADNT) and 2-amino-4,6-dinitrotoluene (2-ADNT). This study highlights the molecular mechanisms of Citrobacter sp. for TNT removal.
希氏杆菌已被证明可以降解 2,4,6-三硝基甲苯（TNT）。然而，其 TNT 生物降解的机制尚不清楚。为了研究在实验开始时和用 TNT 处理 12 小时后细菌生长的差异基因和差异蛋白，进行了整合的蛋白质组和转录组分析。通过 RNA 测序，我们共发现 3792 个转录本和 569 个差异表达基因（≥2 倍，P<0.05）。参与氨基酸转运、细胞代谢和应激蛋白的基因上调，而碳水化合物转运和代谢下调。二维凝胶电泳共显示 42 个蛋白斑点（≥1.5 倍，P<0.05）差异表达，通过质谱鉴定这些蛋白。上调最显著的蛋白参与能量产生和转化、氨基酸转运和代谢、翻译后修饰、蛋白质周转和伴侣。参与碳水化合物转运和代谢的蛋白下调。值得注意的是，我们观察到编码 N-乙基马来酰亚胺还原酶的 nemA 是参与 TNT 降解的上调最显著的基因，并进一步证明它可以将 TNT 转化为 4-氨基-2,6-二硝基甲苯（4-ADNT）和 2-氨基-4,6-二硝基甲苯（2-ADNT）。本研究强调了希氏杆菌去除 TNT 的分子机制。
