semi-deserted soil layers Raw sequence reads. uncultured prokaryote

The sampling sites (84o42′E, 45o36′N) located in the northwest of Dzungharian Basin, northwest of China (Fig. 1A). It is a largely a semi-desert area with the crude oil mining begun on 1950s. The samples were taken in the middle of October 2014. Eight sampling sites dispersed around the whole oilfield mainly closed to the oil-wells were taken by augers and cores, and were divided into different layers as 5-15 cm，25-35 cm，45-55 cm.Total DNA extraction from the petroleum contaminated soil samples. The 16S rRNA gene V4 region was amplified by using barcoded specific primer set 515F (5’-GTGCCAGCMGCCGCGGTAA-3’) and 806R (5’-GGACTACHVGGGTWTCTAAT-3’) . PCR products from different soil layers were then gone library construction and sequencing. Sequencing libraries were generated using TruSeq DNA PCR-Free Sample Preparation Kit (Illumina, USA) following manufacturer’s recommendations, and then the libraries were sequenced on an IlluminaHiSeq 2500 platform.

采样点位（东经84°42′，北纬45°36′）地处中国西北准噶尔盆地（Dzungharian Basin）西北部。该区域主体为半荒漠地带，原油开采始于20世纪50年代。样品采集于2014年10月中旬，共设置8个分散于整个油田且紧邻油井的采样点位，采用螺旋钻与岩芯取样法采集土壤样品，并按5~15 cm、25~35 cm、45~55 cm三个土层深度对样品进行分层。对石油污染土壤样品开展总DNA提取，采用带条形码的特异性引物对515F（5’-GTGCCAGCMGCCGCGGTAA-3’）与806R（5’-GGACTACHVGGGTWTCTAAT-3’）扩增16S rRNA基因的V4可变区。随后对不同土层的PCR扩增产物进行文库构建与测序。参照制造商说明书，采用TruSeq DNA无PCR预扩增样本制备试剂盒（Illumina，美国）构建测序文库，随后在IlluminaHiSeq 2500测序平台上完成测序。