堆肥对土壤中石油烃的去除及微生物群落的影响

Influence of compost amendment on hydrocarbon degradation and microbial communities in petroleum contaminated soil

为研究堆肥对石油污染土壤中不同组分烃的去除作用及土壤微生物群落结构变化的影响,利用重量法和GC-MS测定土壤中总石油烃、烷烃和多环芳烃的含量,采用高通量测序技术研究了堆肥对土壤微生物群落结构和多样性的影响作用.结果表明,向石油污染土壤中施加堆肥进行42d的修复处理,土壤中石油烃、烷烃、多环芳烃去除率分别为(12.4±0.01)%、(10.2±0.01)%、(9.38±0.02)%;自然放置的土壤中3种烃去除率分别为(3.21±0.02)%、(-3.00±0.01)%、(-6.59±0.02)%.自然放置的土壤香农指数、ACE指数和Chao1指数分别为4.30、3489.3和2691.0,加入堆肥进行修复处理后,土壤香农指数、ACE指数和Chao1指数分别增加为5.80、4684.7和3851.8.油污土壤中放线菌门(Actinobacteria)所占丰度由47.3%降低为28.2%,拟杆菌门(Bacteroidetes)丰度由0.78%增加至16.2%.变形菌门(Proteobacteria)丰度为37.4%,修复结束后几乎不变.属水平上,油污土壤中的优势菌属包括原小单孢菌属(promicromonospora)、微小杆菌属(Exiguobacterium)、诺卡氏菌属(Nocardioides)、分支杆菌属(Mycobacterium)、柠檬酸细菌属(Citrobacter).施入堆肥使土壤中的这些优势菌属丰度降低,土壤中出现氮单胞菌属(Azomonas)、藤黄单胞菌属(Luteimonas)、假鞘氨醇杆菌属(Pseudosphingo bacterium)、紫单胞菌属(Parapedobacter)等新菌属.研究结果表明,与自然放置的土壤相比,向石油污染土壤中施入有机堆肥可有效去除土壤中的石油烃、烷烃和多环芳烃.并使土壤微生物群落结构发生明显变化.

A laboratory study was conducted to investigate the effects of compost amendment on hydrocarbon degradation and microbial communities in petroleum contaminated soil. Petroleum hydrocarbons were analyzed using gravimetric method and GC-MS. Illumia Miseq technique was used to detect the microbial community structure of petroleum-polluted soil during the remediation. Results showed the removal efficiencies of total petroleum hydrocarbon（TPH）, alkane, and polycyclic aromatic hydrocarbons（PAHs） were respectively（12.4±0.01）%,（10.2±0.01）%, and（9.38±0.02）% in the compost amendment soil（SC）, compared to（3.21±0.02）%,（-3.00±0.01）%,and（-6.59±0.02）% in the control experiment（CK） after 42 days of incubation. In response to compost amendment, the Shannon index, ACE index, and Chao 1 index increased from 4.30, 3489.3, 2691.0 to 5.80, 4684.7, and 3851.8, respectively. The relative abundance of Actinobacteria phyla decreased from 47.3% to 28.2%, and Bacteroidetes phyla increased from 0.78% to 16.2%. At the genus level, the relative abundance of the dominant genus in the petroleum contaminated soil including promicromonospora, Exiguobacterium, Nocardioides, Mycobacterium, and Citrobacter decreased significantly. Some new genus including Azomonas, Luteimonas, Pseudosphingo bacterium, and Parapedobacter appeared in the compost treated soil. The results indicated mature compost amendment effectively promoted petroleum hydrocarbon degradation in the soil, and soil microbial communities shifted significantly.