焦化土壤中降解苯酚的厌氧反硝化菌群结构

Structure of Phenol-degradation Anaerobic Denitrification Microbial Community in Coking Contaminated Soil

文章通过以苯酚(Phe)或对羟基苯甲酸(4HBA)为唯一碳源和能源建立硝酸根还原条件下的焦化土壤富集菌液,分析焦化污染土壤中苯酚或对羟基苯甲酸的生物降解与硝酸根还原过程,并通过高通量测序技术对比硝酸根还原条件下降解苯酚或对羟基苯甲酸的厌氧反硝化菌群结构多样性。发现苯酚和对羟基苯甲酸降解与硝酸根还原的实际摩尔比分别为1:6.4和1:5.3,与理论计量学比率在合理程度上相近。经过90 d富集后,硝酸根还原条件下土壤富集菌液中降解苯酚的优势门为Proteobacteria、Armatimonadetes和Planctomycetes,而降解对羟基苯甲酸的优势门为Proteobacteria和Bacteroidetes。Betaproteobacteria为优势纲,总相对丰度为46%,Azoarcus分别在降解2种基质的富集菌液中相对丰度最高将近30%,Armatimonadetes_gp5在苯酚为基质的土壤富集菌液中的相对丰度仅次于Azoarcus,推测其很可能是土壤中硝酸根还原条件下降解苯酚的另一优势菌属。

The biodegradation of phenol（Phe） or p-hydroxybenzoate（4HBA） and the nitrate-reducing process were analyzed in coking contaminated soil by the addition of Phe or 4HBA as the sole carbon source and energy source under nitrate reduction condition, then the structure diversity of anaerobic denitrification microbial community of degradation Phe or 4HBA was compared by high throughput sequencing. The molar ratio of Phe or 4HBA degradation and nitrate-reducing was1∶6.4 or 1∶5.3, respectively, which was identify with theoretical stoichiometric ratio. After 90 days enrichment, the dominant phyla for degrading Phe in soil enrichment under the condition of nitrate-reducing were Proteobacteria, Armatimonadetes and Planctomycetes, while for degrading 4HBA were Proteobacteria and Bacteroidetes. Betaproteobacteria was the dominant class, with a total relative abundance of 46%, Azoarcus on the degradation of two kinds of substrates in the highest relative abundance of nearly 30%, the relative abundance of Armatimonadetes_gp5 in Phe after Azoarcus, which was very likely to be another dominant genus of Phe degradation under nitrate-reducing conditions in soil.