Soils polluted with animal charcoal from skin and hide cottage industries harbour extremely toxic and carcinogenic hydrocarbon pollutants and thus require a bio-based eco-friendly strategy for their depuration. The effects of carbon-free mineral medium (CFMM) amendment on hydrocarbon degradation and microbial community structure and function in an animal charcoal-polluted soil was monitored for 6 weeks in field moist microcosms consisting of CFMM-treated soil (FN4) and an untreated control (FN1). Hydrocarbon degradation was monitored using gas chromatography-flame ionization detector (GC-FID), and changes in microbial community structure were monitored using Kraken, while functional annotation of putative open reading frames (ORFs) was done using KEGG KofamKOALA and NCBI’s conserved domain database (CDD). Gas chromatographic analysis of hydrocarbon fractions revealed the removal of 84.02% and 82.38% aliphatic and 70.09% and 70.14% aromatic fractions in FN4 and FN1 microcosms in 42 days. Shotgun metagenomic analysis of the two metagenomes revealed a remarkable shift in the microbial community structure. In the FN4 metagenome, 92.97% of the population belong to the phylum Firmicutes and its dominant representative genera Anoxybacillus (64.58%), Bacillus (21.47%) and Solibacillus (2.39%). In untreated FN1 metagenome, the phyla Proteobacteria (56.12%), Actinobacteria (23.79%) and Firmicutes (11.20%), and the genera Xanthobacter (9.73%), Rhizobium (7.49%) and Corynebacterium (7.35%), were preponderant. Functional annotation of putative ORFs from the two metagenomes revealed the detection of degradation genes for aromatic hydrocarbons, benzoate, xylene, chlorocyclohexane/chlorobenzene, toluene and several others in FN1 metagenome. In the FN4 metagenome, only seven hydrocarbon degradation genes were detected. This study revealed that though CFMM amendment slightly increases the rate of hydrocarbon degradation, it negatively impacts the structural and functional properties of the animal charcoal-polluted soil. It also revealed that intrinsic bioremediation of the polluted soil could be enhanced via addition of water and aeration.

中文翻译：

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无机营养改良剂加重的动物炭污染的土壤在结构和功能特性上的显着变化

皮肤和皮革手工业中被动物木炭污染的土壤含有剧毒和致癌的碳氢化合物污染物，因此需要采用基于生物的生态友好策略进行净化。在由CFMM处理过的土壤（FN4）和未经处理的对照组成的田间湿地缩微环境中，监测了无碳矿质培养基（CFMM）改性剂对动物木炭污染的土壤中碳氢化合物降解以及微生物群落结构和功能的影响，持续了6周。 （FN1）。使用气相色谱-火焰电离检测器（GC-FID）监测碳氢化合物的降解，并使用Kraken监测微生物群落结构的变化，同时使用KEGG KofamKOALA和NCBI的保守域数据库对假定的开放阅读框（ORF）进行功能注释（ CDD）。烃馏分的气相色谱分析显示，在42天之内，FN4和FN1微观结构中84.02％和82.38％的脂肪族部分以及70.09％和70.14％的芳族部分被去除。gun弹枪对这两个基因组的宏基因组学分析表明，微生物群落结构发生了显着变化。在FN4元基因组中，有92.97％的人口属于Firmicutes门，其主要代表种是Anoxybacillus（64.58％），Bacillus（21.47％）和Solibacillus（2.39％）。在未经处理的FN1基因组中，门菌属（56.12％），放线菌（23.79％）和Firmicutes（11.20％）以及黄杆菌（9.73％），根瘤菌（7.49％）和棒杆菌（7.35％）占优势。从两个元基因组推定的ORF的功能注释揭示了对芳烃，苯甲酸酯，二甲苯，FN1元基因组中的氯环己烷/氯苯，甲苯和其他几种。在FN4元基因组中，仅检测到七个碳氢化合物降解基因。这项研究表明，尽管CFMM修正剂略微增加了碳氢化合物的降解速度，但对动物炭污染的土壤的结构和功能特性产生了负面影响。研究还表明，通过添加水和通气，可以增强污染土壤的内在生物修复作用。