基于16S rRNA基因序列分析受砷和硫酸盐污染的土壤细菌多样性（英文稿）

Characterization of bacteria community associated with soil arsenic and sulphate contamination based on 16S rRNA gene sequences

摘要:

为了了解普通耕地土壤(Nor-1)和受砷及硫酸盐污染土壤(Sul-1)中的细菌组成和多样性差异, 对2个不同土壤样品直接提取总DNA, 通过PCR扩增16S rRNA基因并建立文库, 对文库克隆进行核糖体DNA扩增片段酶切分析(ARDRA)和测序, 构建系统进化树。从Nor-1土壤样品中测序获得23个16S rRNA基因序列, 分析序列系统发育关系表明, 共包含 Acidobacteria (12.3%, 8/65)、Actinobacteria (3.1%, 2/65)、Firmicutes (21.5%, 14/65)、Nitrospira (3.1%, 2/65)和Proteobacteria (60%, 39/65)等5个不同细菌门。而从Sul-1土壤样品中测序获得19个16S rRNA基因序列, 分析序列系统发育关系表明, 共包含 Firmicutes (29.5%, 13/44)和Proteobacteria (70.5%, 31/44)等2个不同细菌门。结果表明, 受高浓度的砷和硫酸盐的影响, Sul-1土壤中细菌群落结构相较于普通耕地土壤(Nor-1)发生了明显的改变, 多样性明显下降, 但有大量具有较强的污染物降解能力的不动杆菌(Acinetobacter)相关序列在Sul-1土壤细菌群落中被发现。

Abstract:

In order to investigate molecular diversity of bacteria community from both a normal arable soil (Nor-1) and an arsenic and sulphate polluted soil (Sul-1). Environmental total DNA was directly extracted from two soil samples. The 16S rRNA genes were amplified from the total DNA and construction a clone library. Positive clones were randomly selected from the library and identified by amplified ribosomal DNA restriction analysis (ARDRA) and sequencing, then constructed phylogenetic tree. 23 unique clone sequences from Nor-1 soil were classified into 5 bacterial phylum including Acidobacteria (12.3%, 8/65), Actinobacteria(3.1%, 2/65), Firmicutes (21.5%, 14/65), Nitrospira (3.1%, 2/65) and Proteobacteria (60%, 39/65), while 19 unique clone sequences from Sul-1 soil were classified into 2 bacterial phylum including Firmicutes (29.5%, 13/44), and Proteobacteria (70.5%, 31/44). The result suggested that the high concentration of arsenic and sulphate influenced the bacterial population of Sul-1 soil leading to construction of obviously specific bacteria community. Interestingly, a lot of Acinetobacter related sequences have been detected in Sul-1 soil bacteria community including clone Sul11/15, Sul12/7 and Sul12/11. Because Acinetobacter strains are often ubiquitous, exhibit metabolic versatility, those related strains may be good targets for exploiting novel arsenic detoxification bacteria.