Background

Since the industrial revolution, the contamination of agricultural soils by polycyclic aromatic hydrocarbons (PAHs) has increasingly become of serious global environmental concern and poses a huge threat to human beings and natural ecosystems. Microbial degradation is a proved technology mostly used to depollute polycyclic aromatic hydrocarbon (PAH) in the environment. However, very limited information is available regarding the interaction of earthworms with rice straw on the soil microbial community and the degradation of phenanthrene. This study was performed to enlighten the rice straw and earthworms’ interaction on soil bacterial abundance and structure and phenanthrene removal.

Results

Result about functional gene information revealed that both rice straw and earthworm enhanced phenanthrene degradation. Subsequently, both Shannon diversity index (r² = − 0.8807, p < 0.001) and bacterial 16S rRNA genes (r² = − 0.7795, p < 0.001) negatively correlated with the remaining phenanthrene concentration in soil. The application of both rice straw and earthworms in soil had the lowest ratio of soil remaining phenanthrene concentration (0.16 ± 0.02), the highest Shannon diversity index (6.45 ± 0.2) and the highest bacterial 16S rRNA genes. This implied that both earthworms and rice straw might improve the phenanthrene metabolism by increasing soil bacteria diversity. The abundance of genera Pseudomonas, Luteimonas, Rhodanobacter, Sphingomonas, Gemmatimonas, Flavobacterium, and Leifsonia was significantly increased in the presence of both earthworms and rice straw and was found to negatively correlate with the remaining phenanthrene concentration in soil.

Conclusion

Based on these results, this study offers clear and strong evidences that the positive interaction between earthworms and rice straw could promote phenanthrene degradation in soil. These finding will improve our understanding on the importance of the natural resources forsaken and how they can interact with the soil macro- and microorganisms to change soil structure and enhance PAH degradation in soil.

中文翻译：

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and和稻草可增强土壤细菌多样性并促进菲的降解

背景

自工业革命以来，多环芳烃（PAHs）对农业土壤的污染已日益引起全球严重关注，对人类和自然生态系统构成了巨大威胁。微生物降解是一项经过验证的技术，主要用于去除环境中的多环芳烃（PAH）污染。但是，关于regarding与稻草在土壤微生物群落上的相互作用以及菲的降解的信息非常有限。这项研究的目的是启发稻草和earth在土壤细菌丰度和结构以及菲去除方面的相互作用。

结果

有关功能基因信息的结果表明，稻草和enhanced均促进了菲的降解。随后，香农多样性指数（r ²  =-0.8807，p  <0.001）和细菌16S rRNA基因（r ²  =-0.7795，p  <0.001）与土壤中剩余的菲浓度呈负相关。稻草和earth在土壤中的应用具有最低的土壤残留菲浓度比（0.16±0.02），最高的Shannon多样性指数（6.45±0.2）和最高的细菌16S rRNA基因。这意味着earth和稻草都可以通过增加土壤细菌的多样性来改善菲的代谢。丰富的属假单胞菌，Luteimonas，Rhodanobacter，鞘氨醇，Gemmatimonas，黄杆菌，并Leifsonia两个蚯蚓和稻草的存在显著上升，并发现负相关，在土壤中剩余的菲浓度。

结论

基于这些结果，这项研究提供了明确而有力的证据，表明and与稻草之间的积极相互作用可以促进土壤中菲的降解。这些发现将增进我们对自然资源的重要性及其如何与土壤宏观和微生物相互作用以改变土壤结构并增强土壤中PAH降解的理解。