Jayamani Indumathy, Cupples Alison M
A135 Research Engineering Complex, Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, 48824, USA.
Environ Sci Pollut Res Int. 2015 Jul;22(13):10340-50. doi: 10.1007/s11356-015-4256-6. Epub 2015 Feb 28.
This study investigated the microorganisms involved in hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) degradation from a detonation area at a Navy base. Using Illumina sequencing, microbial communities were compared between the initial sample, samples following RDX degradation, and controls not amended with RDX to determine which phylotypes increased in abundance following RDX degradation. The effect of glucose on these communities was also examined. In addition, stable isotope probing (SIP) using labeled ((13)C3, (15)N3-ring) RDX was performed. Illumina sequencing revealed that several phylotypes were more abundant following RDX degradation compared to the initial soil and the no-RDX controls. For the glucose-amended samples, this trend was strong for an unclassified Pseudomonadaceae phylotype and for Comamonas. Without glucose, Acinetobacter exhibited the greatest increase following RDX degradation compared to the initial soil and no-RDX controls. Rhodococcus, a known RDX degrader, also increased in abundance following RDX degradation. For the SIP study, unclassified Pseudomonadaceae was the most abundant phylotype in the heavy fractions in both the presence and absence of glucose. In the glucose-amended heavy fractions, the 16S ribosomal RNA (rRNA) genes of Comamonas and Anaeromxyobacter were also present. Without glucose, the heavy fractions also contained the 16S rRNA genes of Azohydromonas and Rhodococcus. However, all four phylotypes were present at a much lower level compared to unclassified Pseudomonadaceae. Overall, these data indicate that unclassified Pseudomonadaceae was primarily responsible for label uptake in both treatments. This study indicates, for the first time, the importance of Comamonas for RDX removal.
本研究调查了海军基地爆炸区域中参与六氢-1,3,5-三硝基-1,3,5-三嗪(RDX)降解的微生物。利用Illumina测序技术,对初始样品、RDX降解后的样品以及未添加RDX的对照样品中的微生物群落进行了比较,以确定RDX降解后哪些系统发育型的丰度增加。还研究了葡萄糖对这些群落的影响。此外,使用标记的((13)C3,(15)N3-环)RDX进行了稳定同位素探测(SIP)。Illumina测序显示,与初始土壤和无RDX对照相比,RDX降解后几种系统发育型的丰度更高。对于添加葡萄糖的样品,未分类的假单胞菌科系统发育型和丛毛单胞菌属的这种趋势很明显。在没有葡萄糖的情况下,与初始土壤和无RDX对照相比,不动杆菌属在RDX降解后增加最多。红球菌属是已知的RDX降解菌,在RDX降解后其丰度也增加。对于SIP研究,无论有无葡萄糖,未分类的假单胞菌科都是重质组分中最丰富的系统发育型。在添加葡萄糖的重质组分中,也存在丛毛单胞菌属和厌氧粘细菌属的16S核糖体RNA(rRNA)基因。没有葡萄糖时,重质组分中还含有偶氮氢单胞菌属和红球菌属的16S rRNA基因。然而,与未分类的假单胞菌科相比,所有这四种系统发育型的含量都要低得多。总体而言,这些数据表明,在两种处理中,未分类的假单胞菌科是主要负责标记物摄取的菌群。本研究首次表明了丛毛单胞菌属对RDX去除的重要性。