Abstract：
Biostimulation (providing favorable environmental conditions for microbial growth) and bioaugmentation (introducing exogenous microorganisms) are effective approaches in the bioremediation of petroleum-contaminated soil. However, uncertainty remains in the effectiveness of these two approaches in practical application. In this study, we constructed mesocosms using petroleum hydrocarbon-contaminated soil. We compared the effects of adding nutrients, introducing exogenous bacterial degraders, and their combination on remediating petroleum contamination in the soil. Adding nutrients more effectively accelerated total petroleum hydrocarbon (TPH) degradation than other treatments in the initial 60 days\' incubation. Despite both approaches stimulating bacterial richness, the community turnover caused by nutrient addition was gentler than bacterial degrader introduction. As TPH concentrations decreased, we observed a succession in microbial communities characterized by a decline in copiotrophic, fast-growing bacterial r-strategists with high rRNA operon (rrn) copy numbers. Ecological network analysis indicated that both nutrient addition and bacterial degrader introduction enhanced the complexity and stability of bacterial networks. Compared to the other treatment, the bacterial network with nutrient addition had more keystone species and a higher proportion of negative associations, factors that may enhance microbial community stability. Our study demonstrated that nutrient addition effectively regulates community succession and ecological interaction to accelerate the soil TPH degradation.
摘要：
生物刺激（为微生物生长提供有利的环境条件）和生物增强（引入外源微生物）是石油污染土壤的生物修复的有效方法。然而,这两种方法在实际应用中的有效性仍然存在不确定性。在这项研究中,我们使用石油碳氢化合物污染的土壤构建了介观。我们比较了添加营养素的效果，引入外源细菌降解物，以及它们在修复土壤中石油污染方面的组合。在最初的60天孵育中，添加营养素比其他处理更有效地加速了总石油烃（TPH）的降解。尽管这两种方法都能刺激细菌丰富，营养添加引起的社区周转比细菌降解剂引入温和。随着TPH浓度的降低,我们观察到微生物群落的演替特征是共营养减少，具有高rRNA操纵子（rrn）拷贝数的快速生长的细菌r策略家。生态网络分析表明，营养添加和细菌降解剂的引入都增强了细菌网络的复杂性和稳定性。与其他治疗相比，添加营养的细菌网络具有更多的关键物种和更高的负关联比例，可能增强微生物群落稳定性的因素。我们的研究表明，养分添加有效地调节了群落演替和生态相互作用，从而加速了土壤TPH的降解。
