煤矸石充填不同复垦年限土壤细菌群落结构及其酶活性

摘要

In this study, soil samples from the reclaimed land filled with coal gangue (SS) with different reclamation years (2015, 2010, and 2001 years) in Xuzhou mining area and from normal farmlands which were not affected by coal mining subsidence (SSC) were collected. The sequence numbers of bacterial community were determined by the Illumina PE250sequencing method, and the vertical structure and time structure were analyzed. The results showed that: (1) Reclamation decreased the number of bacteria species and the community diversity, but the goodness between SS and SSC increased with the age of reclamation. (2) Firmicutes and Proteobacteria dominated in SS at the phylum level, the number of Firmicutes increased after reclamation and Firmicutes also likely transferred from 20~40cm to 0~20cm soil layer. (3) Bacilli predominantly existed in soils at the class level, the number of Bacilli in 0~20cm soil layer was higher in SS than in SSC samples, and the number in 20~40cm soil layers of SS samples decreased with the increase of the reclamation years. (4) Lactobacillales and Bacillales dominated in SS at the order level. Desulfuromonadales played an important role in the remediation of heavy metal pollution and its number in 0~20cm soil layer of SS was 74.81~99.59% less than that in SSC samples. (5) In SS samples, Bacillus, Enterococcus and Streptococcaceae were the dominant family, while Bacillus, Enterococcus and Lactococcus were the dominant genus, and Bacillus sp. JH7, Enterococcus faecium and Lactococcus piscium were the dominant species. All of these in SS samples were less in number than SSC samples especially in 0~20cm soil layer, while the number in 20~40cm soil layer of SS decreased with the increase of the reclamation years. (6) Dehydrogenase activity was negatively correlated with the number of Firmicutes.spp, but was positively correlated with the number of Actinobacteria and the number of Gammaproteobacteria. Also, the type of dominant soil bacteria did not change, but their quantitative structure varied over time. Owing to Firmicutes are suitable for growth in the absence of water and extreme environments, but Proteobacteria is conducive to soil nitrogen and energy cycling. Therefore, the soil quality was improved by adjusting soil bacterial community structure and shorten the recovery period.%基于徐州市3块煤矸石充填复垦地(复垦时间分别为2015、2010和2001年)的土壤样本,采用Illumina PE250测序方法测定微生物群落组分,以未受采煤塌陷影响区的土壤样本为对照地,对比分析充填复垦区细菌群落的垂直结构及其时间变化.结果表明:(1)与对照地相比,复垦土壤在各个分类水平的细菌种类数量减少,群落多样性降低.随着复垦年限的增加,复垦地与对照地的贴近度越高.(2)厚壁菌门、变形菌门是复垦土壤中门水平的优势菌,厚壁菌门在复垦土壤中优势地位上升,有从20~40cm土层向0~20cm土层转移的趋势.(3)芽孢杆菌纲在纲水平占绝对优势,在复垦土壤0~20cm土层中的数量多于对照土壤,在复垦土壤20~40cm土层的数量随年限增加而减少.(4)乳杆菌目、芽孢杆菌目在目水平是优势菌,除硫单胞菌目对重金属污染修复有重要作用,然而在复垦土壤的0~20cm 土层中的数量比正常农田土壤少74.81%~99.59%.(5)芽孢杆菌科、肠球菌科、链球菌科是科水平的优势菌,芽孢杆菌属、肠球菌属、乳球菌属是属水平的优势菌,芽孢杆菌属-JH7、屎肠球菌、乳球菌属-piscium是种水平的优势菌,3大类在复垦土壤中的数量比例大于正常农田,且在0~20cm土层中的差别更明显,在复垦土壤的20~40cm土层的数量随年限增加而减少.(6)脱氢酶活性与厚壁菌门下的多种细菌的数量呈显著负相关,与放线菌门的数量呈显著正相关,与 γ-变形菌纲的数量呈极显著正相关.随着复垦年限的增加,土壤优势菌群的类型没有变化,但是数量结构在变化.厚壁菌门在缺水和极端环境下适合生长,变形菌门有助于土壤氮素以及能量的循环.采用微生物修复技术,调整土壤细菌群落结构,可以改善土壤质量,缩短土壤恢复年限.