Bacterial community dynamics and enhanced degradation of di-n-octyl phthalate (DOP) by corncob-sodium alginate immobilized bacteria
Bacterial community dynamics and enhanced degradation of di-n-octyl phthalate (DOP) by corncob-sodium alginate immobilized bacteria
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DOI：
10.1016/j.geoderma.2017.06.009
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发表时间：
2017-11
期刊：
影响因子：
6.1
通讯作者：
Ke Zhang;Yihao Liu;Hongbing Luo;Qiang Chen;Zhanyuan Zhu;Wei Chen-;Jia Chen;Lin Ji;You Mo
中科院分区：
文献类型：
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作者：
Ke Zhang;Yihao Liu;Hongbing Luo;Qiang Chen;Zhanyuan Zhu;Wei Chen-;Jia Chen;Lin Ji;You Mo
从活性污泥中分离到一株能利用DOP作为碳源和能源的细菌ETG-101。根据16 SrRNA基因序列分析，菌株ETG-101为伯克霍尔德氏菌属（Burkholderiasp.）对DOP降解中间产物的分析表明，菌株ETG-101可通过脱酯化途径将DOP完全降解，该途径将二酯转化为单酯，并将DOP转化为M-n-O-P，M-n-O-P再代谢为邻苯二甲酸（PA），最终进入三羧酸（TCA）循环。进一步将菌株ETG-101固定在复合载体（玉米芯和海藻酸钠）中。环境因子试验表明，固定化细胞比游离细胞具有更宽的pH和温度范围。载体和包埋介质对土壤中DOP的去除效果有显著影响。结果表明，玉米芯-海藻酸钠（SA）固定化细胞对土壤中DOP的去除率最高，达到78.1%，分别是玉米芯和游离细胞的60倍和2.3倍。采用实时荧光定量PCR（q-PCR）和Illumina Miseq测序技术研究了土壤中细菌数量和群落结构动态。结果表明，将游离细胞接种到土壤中可显着减少土壤细菌数量并改变细菌群落结构，而将固定化细胞引入土壤中可增加细菌总数并轻微改变细菌群落组成。随着驯化过程的进行，鞘氨醇单胞菌和红环菌逐渐消失，伯克霍尔德氏菌与不动杆菌、拟杆菌和节杆菌均为游离和固定化细胞系统中的优势菌属，可能是土壤系统中DOP降解的主要菌属。玉米芯-海藻酸钠固定化细菌显著提高了土壤中DOP的降解，对土壤生物多样性影响不大。因此，该固定化方法在修复DOP污染土壤中具有潜在的应用价值。
A bacterial strain designated as ETG-101, capable of utilizing DOP as source of carbon and energy, was isolated from activated sludge. According to the 16 s rRNA gene sequences, strain ETG-101 was identified asBurkholderiasp. Analysis of DOP degradation intermediates indicated that strain ETG-101 could completely degrade DOP via de-esterification pathway that transforms di-esters to monoesters, where DOP was transferred to M-n-O-P which in turn metabolized to phthalic acid (PA) and eventually entered into tricarboxylic acid (TCA) cycle. Further, strain ETG-101 was immobilized into complex carriers (corncob and sodium alginate). The environmental factors tests demonstrated that the immobilized cells had broader range of pH and temperature than free cells. Carrier and entrapment media significantly affected the efficiency of DOP removal in soil. Corncob-sodium alginate (SA) immobilized cells had the highest DOP removal rate of 78.1% in soil, which was 60-fold and 2.3-fold more increase in DOP removal rate compared to corncob and free cells, respectively. The bacterial quantity and community structure dynamics in soil were also investigated by the real-time quantitative PCR (q-PCR) and Illumina Miseq sequencing. The results revealed that inoculation of free cells into soil significantly reduced the bacterial quantity of soil and altered the bacterial community structure, whereas the introduction of immobilized cells to soil increased the total bacterial quantity and slightly changed the bacterial community composition. As the acclimatization,SphingomonasandRhodocyclusgradually disappeared when free cells were inoculated to soil.Burkholderiaalong withAcinetobacter,BacteroidesandArthrobacterwere the predominant genera in both free and immobilized cells systems, which were probably responsible for DOP biodegradation in soil system. Corncob-sodium alginate immobilized bacteria significantly enhanced DOP biodegradation in soil and had little impact on soil biodiversity. Therefore this immobilization method has potential in DOP-contaminated soil remediation.