多环芳烃共代谢对苯并[a]蒽微生物降解的影响及机制

利用14C同位素示踪技术,研究土壤中菲、蒽、芘3种底物对苯并a]蒽(BaA)环境归趋的影响,高通量测序解析细菌群落响应.结果表明,3种底物均可以促进BaA的降解,添加蒽作为共代谢底物后,BaA矿化率比对照提高了2.5％,而添加菲、芘时,14C在土壤的结合态比对照升高4％,达总添加量的31％.共代谢底物改变了细菌共生网...

Effect of co-metabolism by polycyclic aromatic hydrocarbon on the microbial degradation of benzo[a]anthracene and its mechanism

In this study, the effect of three co-metabolic substrates (phenanthrene, anthracene, pyrene) on environmental distribution of benzoa]anthracene (BaA) was studied by using ¹⁴C isotope tracer. High-throughput sequencing and co-occurrence network analysis were used to evaluate bacterial community responses. The results demonstrated that all the three co-metabolic substrates promoted degradation of BaA. The mineralization of BaA increased by 2.5% in the anthracene treatment compared to the control. In the treatments of phenanthrene and pyrene, the bound residue of ¹⁴C was 4% higher than in the control, amounting to 31% of the total addition. The topological characteristics of bacterial co-occurrence network changed with the supplementation of co-metabolic substrates. Anthracene significantly raised the proportion of positive links, which indicated mutualistic interactions. In contrast, the competition between bacterial taxa was strengthened in the treatments of phenanthrene and pyrene, as evidenced by increased negative links after incubation. It was likely that anthracene and BaA degraded through common metabolic pathways, which caused mutualistic interactions and higher mineralization rate of BaA in the soil microcosms. Overall, co-metabolism could be an important factor influencing the fate of BaA in soil and changing the interaction among bacterial species.