【摘要】 从活性污泥中分离获得一株PCL降解菌,经形态学和16S rDNA鉴定后命名为Pseudomonas sp.JQ-H3.经过脱氮实验验证,该菌能够以PCL为唯一碳源,分别以氨氮或硝酸盐氮为氮源进行异养硝化好氧反硝化.该菌能够在36h内去除93.11%的氨氮(初始氨氮浓度为102.41mg/L),氨氮最大降解速率为5.77mg/(L·h);并且能够在48h内去除93.93%的硝酸盐氮(初始氨氮浓度为99.01mg/L),硝酸盐氮最大降解速率为4.12mg/(L·h).对PCL膜的降解实验结果表明,菌株能够在60d内将初始重量为100mg的PCL薄膜降解94.03%,且胞外脂肪酶活性在30d时达到最大值9.18mU/mL.另外,Q-PCR实验结果表明,弱碱性环境促进了amoA和nirS基因的表达; napA、cnorB、nosZ基因的成功表达,进一步证明了菌株的异养硝化好氧反硝化能力.更多还原

【Abstract】 A PCL-degrading strain was isolated and identified as Pseudomonas sp. JQ-H3 through morphology observation and phylogenetic analysis. The strain showed the heterotrophic nitrification-aerobic denitrification(HN-AD) ability using PCL as a sole carbon source. About 93.11% of initial ammonium(102.41 mg/L) was degraded within 36 h with the maximum ammonium removal rate of 5.77 mg/(L·h), while approximately 93.93% of initial nitrate(99.01 mg/L) was removed within 48 h with the maximum ammonium removal rate of 4.12 mg/(L·h). 94.03% of PCL film with initial weight of 100 mg was decomposed after 60 days, and the extracellular lipases activity reached the maximum value of 9.18 mU/mL at 30 th days. In addition, the expression levels of amo A and nirS genes were promoted in the weak alkaline environment. The successful expression of napA, cnor B and nosZ genes further proved the HN-AD ability of the strain JQ-H3.更多还原