Assessment of the bacterial community structure in a Brazilian clay soil treated with atrazine
Assessment of the bacterial community structure in a Brazilian clay soil treated with atrazine
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DOI：
10.1007/s13213-013-0665-2
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发表时间：
2014-03-01
影响因子：
3
通讯作者：
Caracciolo, Anna Barra
中科院分区：
文献类型：
--
作者：
Godoi, Isamara;Sene, Luciane;Caracciolo, Anna Barra
本文采用荧光原位杂交(FISH)技术，对甘蔗农田土壤和地质学性质相似的原状土壤中的细菌群落进行了研究。FISH包括使用荧光标记的16S rRNA靶向寡核苷酸探针对细菌进行原位鉴定，该探针在荧光显微镜下可见。在耕作土壤上，根据农业实际，每年定期喷洒出苗前除草剂阿特拉津，浓度为5 L/公顷。还利用FISH分析获得的系统发育数据计算了Shannon多样性和均匀度指数。尽管在采样时间(土壤阿特拉津处理后6个月)没有发现除草剂残留浓度，但总体细菌群落结果显示，农业土壤中的多样性和均匀度低于未受干扰的土壤，表明微生物指标对人为干扰非常敏感。在自然土壤中，优势类群是α-变形杆菌、β-变形杆菌和伽玛变形杆菌(占细菌总数的50%以上)，而在农业土壤中，它们的丰度显著下降，仅占细菌域的31%。
In the present paper, the bacterial communities in two soils, one from an agricultural sugarcane cropped field and the other from an unperturbed soil with similar geopedological characteristics, were characterized using the Fluorescence In Situ Hybridization (FISH) method. FISH consists of in situ identification of bacteria using fluorescent labeled 16S rRNA targeted oligonucleotide probes visualizable under epifluorescence microscope. In the cultivated soil, in line with agricultural practice, the pre-emergence herbicide atrazine had been regularly applied each year at a concentration of 5 L/ha. The Shannon Diversity and Evenness Indices were also calculated using the phylogenetic data obtained from the FISH analysis. Although, at the sampling time (6 months after soil atrazine treatment), no residual herbicide concentration was found, the overall bacterial community results show a lower diversity and evenness in the agricultural soil than in the unperturbed one, demonstrating how microbiological indicators are sensitive to anthropogenic disturbance. In the natural soil, the dominant groups were alpha-Proteobacteria, beta-Proteobacteria, and gamma-Proteobacteria (representing more than 50 % of the bacteria), but in the agricultural soil, their abundance decreased significantly and represented just 31 % of the bacteria domain.