DNA提取前处理方法对太岁里层样品中细菌种群结构的影响

The effect of DNA extraction pretreatment methods on the bacterial community structure of Taisui inner tissue

为了评价不同DNA提取前处理方法对太岁里层样品中细菌种群结构的影响,并解析优势结构,对太岁里层重复取样,在提取细菌DNA前,分别施以水浸提(SI1)、浸提后热溶解(SI2)、直接热溶解(SI3)3种不同前处理,同时与微孔滤膜过滤相结合,在高通量测序后以操作分类单元(operational taxonomic unit,OTU)为基础深度分析细菌种群结构。结果表明,SI1、SI2和SI3的Shannon指数分别为2.96、3.10和3.08,OTU数目分别为891、964和1095个,共有OTU 313个,其序列之和占总序列的96.02%。细菌种群在各分类水平上的数目互有差别,SI1最少,优势种群高度集中于假单胞菌属(Pseudomonas)和不动杆菌属(Acinetobacter),所占比例之和超过60%。其中,假单胞菌属独占42.30%~56.35%,较之前研究结果变化最大。OTU的分布和丰度在不同取样位置间不均衡。3种前处理方法测得的细菌结构近似,但以SI3测得的假单胞菌属中丰度最高OTU,在总序列中所占比例最高,为41.14%。

The purpose of this study was to evaluate the effects of different pre-treatment methods of DNA extraction on the structure of bacterial community in the inner tissue of Taisui,and the dominant community structure was analyzed.Before the extraction of bacterial DNA,the repeated sampling of the inner tissue of Taisui was treated by three kinds of pre-treatments,ie.,water extraction(SI1),thermal dissolution(SI2)and direct thermal dissolution(SI3)respectively,in combination with micro porous membrane filtration,followed by high-throughput sequencing analysis of bacterial community structure based on the operational taxonomic unit(OTU).The results demonstrated that Shannon indices of SI1,SI2 and SI3 were 2.96,3.10 and 3.08,respectively.Meanwhile,the number of OTUs was 891,964 and 1095,respectively.There were 313 OTUs,and the sum of the sequences accounted for 96.02%of the total sequence.There were differences in the number of bacterial communities at each classification level,with SI1 being the least,but the dominant communities were highly concentrated in Pseudomonas and Acinetobacter,accounting for more than 60%of the total.Among them,Pseudomonas has a monopoly of 42.30%~56.35%,which is the biggest change compared with previous research results.The distribution and abundance of the OTU were also uneven among differentsampling locations.The structures of the bacteria community measured by the three pretreatment methods were similar,but the most dominant OTU of Pseudomonas obtained by thermal dissolving membrane filtration method had the highest proportion accounting for 41.14%.