Petroleum contaminated soil is considered among the most important potential anthropogenic atmospheric methane sources. Additionally, various rhizoremediation factors can affect methane emissions by altering soil ecosystem carbon cycles. Nonetheless, greenhouse gas emissions from soil have not been given due importance as a potentially relevant parameter in rhizoremediation techniques. Therefore, this study sought to investigate the effects of different plant and soil amendments on both remediation efficiencies and methane emission characteristics in diesel-contaminated soil. An indoor pot experiment consisting of three plant treatments (control, maize, tall fescue) and two soil amendments (chemical nutrient, compost) was performed for 95 days. Total petroleum hydrocarbon (TPH) removal efficiency, dehydrogenase activity, and alkB (alkane compound degrading enzyme) gene abundance were the highest in the tall fescue and maize soil system amended with compost. Compost addition enhanced both the overall remediation efficiencies, as well as pmoA (i.e., a methane oxidizing enzyme) gene abundance in soils. Moreover, the potential methane emission of diesel-contaminated soil was relatively low when maize was introduced to the soil system. After microbial community structure analysis, various TPH degrading microorganisms (Nocardioides, Marinobacter, Immitisolibacter, Acinetobacter, Kocuria, Mycobacterium, Pseudomonas, Alcanivorax) and methane-oxidizing microorganisms (Methylocapsa, Methylosarcina) were observed in the rhizosphere soil. The effects of major rhizoremediation factors on soil remediation efficiency and greenhouse gas emissions discussed herein are expected to contribute to the development of sustainable biological remediation technologies in response to global climate change.

中文翻译：

---

植物和土壤改良剂对石油污染土壤中根茎修复性能和甲烷减排的影响。

石油污染的土壤被认为是最重要的潜在人为大气甲烷来源之一。此外，各种根茎修复因素可以通过改变土壤生态系统碳循环来影响甲烷排放。尽管如此，土壤中的温室气体排放并未作为根茎修复技术中潜在的相关参数得到应有的重视。因此，本研究旨在调查不同植物和土壤改良剂对柴油污染土壤的修复效率和甲烷排放特性的影响。一项为期 95 天的室内盆栽实验由三种植物处理（对照、玉米、高羊茅）和两种土壤改良剂（化学养分、堆肥）组成。总石油烃 (TPH) 去除效率、脱氢酶活性和alkB（烷烃化合物降解酶）基因丰度在堆肥改良的高羊茅和玉米土壤系统中最高。添加堆肥既提高了整体修复效率，也提高了土壤中pmoA（即甲烷氧化酶）基因的丰度。此外，当将玉米引入土壤系统时，柴油污染土壤的潜在甲烷排放量相对较低。经过微生物群落结构分析，各种TPH降解微生物（Nocardioides、Marinobacter、Immitisobacter、Acinetobacter、Kocuria、Mycobacterium、Pseudomonas、Alcanivorax）和甲烷氧化微生物（Methylocapsa、Methylosarcina）) 在根际土壤中观察到。本文讨论的主要根茎修复因子对土壤修复效率和温室气体排放的影响有望促进可持续生物修复技术的发展，以应对全球气候变化。