Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis.
Biodegradation of DDT by Stenotrophomonas sp. DDT-1: Characterization and genome functional analysis.
复制标题
寡养单胞菌对滴滴涕的生物降解。
DOI：
10.1038/srep21332
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发表时间：
2016-02-18
影响因子：
4.6
通讯作者：
Yu Y
中科院分区：
文献类型：
--
作者：
Pan X;Lin D;Zheng Y;Zhang Q;Yin Y;Cai L;Fang H;Yu Y
从受DDT污染的土壤中分离到一株能利用DDT作为唯一碳源和能源的细菌，经形态学、BIOPOLYGN 2微板图谱和16 S rDNA序列分析，鉴定为Stenotrophomonasp. DDT-1。DDT-1的基因组序列分析和功能注释表明，DDT-1基因组大小为4，514，569 bp，GC含量为66.92%，包含4，033个蛋白质编码基因和76个RNA基因，其中包括8个rRNA基因。总共有2，807个蛋白质编码基因被分配到Orthopathic Groups（COG）的聚类中，1，601个蛋白质编码基因被定位到京都基因和基因组百科全书（KEGG）途径。DDT的降解半衰期随底物浓度的增加而增加，但随温度的升高而降低。中性条件最有利于DDT的生物降解。基于DDT降解基因的基因组注释和GC-MS检测到的代谢产物，提出了DDT降解的矿化途径：DDT通过脱氯、羟基化和羧化依次转化为DDE/DDD、DDMU、DDOH和DDA，最终矿化为CO2。结果表明，分离菌株DDT-1是一种很有前途的去除或解毒环境中DDT残留的细菌资源。
A novel bacterium capable of utilizing 1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane (DDT) as the sole carbon and energy source was isolated from a contaminated soil which was identified as Stenotrophomonas sp. DDT-1 based on morphological characteristics, BIOLOG GN2 microplate profile and 16S rDNA phylogeny. Genome sequencing and functional annotation of the isolate DDT-1 showed a 4,514,569 bp genome size, 66.92% GC content, 4,033 protein-coding genes and 76 RNA genes including 8 rRNA genes. Totally, 2,807 protein-coding genes were assigned to Clusters of Orthologous Groups (COGs) and 1,601 protein-coding genes were mapped to Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. The degradation half-lives of DDT increased with substrate concentration from 0.1 to 10.0 mg/l, whereas decreased with temperature from 15 °C to 35 °C. Neutral condition was the most favorable for DDT biodegradation. Based on genome annotation of DDT degradation genes and the metabolites detected by GC-MS, a mineralization pathway was proposed for DDT biodegradation in which it was orderly converted into DDE/DDD, DDMU, DDOH and DDA via dechlorination, hydroxylation and carboxylation and ultimately mineralized to carbon dioxide. The results indicate that the isolate DDT-1 is a promising bacterial resource for the removal or detoxification of DDT residues in the environment.