【摘要】 为研究As (砷)污染对微生物多样性的影响,找寻有利于As污染修复的抗As菌种,利用高通量测序技术分析As胁迫[w(As)分别为0、80、100、150、200和400 mg/kg,依次记为AT0组、AT80组、AT100组、AT150组、AT200组和AT400组]对湿地生境中土壤微生物多样性及群落结构特征的影响.结果表明:As污染会引起微生物多样性和群落结构的变化,但并不是简单的负相关.在各处理组中,AT80组的土壤中微生物多样性最高,OTU (operational taxonomic units)数高达1 849,较未经As处理的AT0组增加了58. 9%,说明低As胁迫在一定程度上会刺激As敏感微生物的生长繁殖,如Desulfovibrio (脱硫弧菌属)和Allobaculum等菌属,使群落结构更加复杂多样.高w(As)(400 mg/kg)对微生物有明显的抑制作用,导致某些物种消亡和多样性下降. As胁迫会诱导抗As微生物[如Pseuomonas (假单胞菌属)]成为优势类群,群落结构趋于稳定、单一.微生物群落结构对不同w(As)胁迫有明显的响应特征,可作为As污染湿地土壤质量评价的灵敏指标.在AT400组中存在大量的Pseudomonas veronii,可为As污染湿地微生物修复提供借鉴.研究显示,微生物对As污染具有较为敏感的响应,其中,Proteobacteria (变形菌门)和Firmicutes(厚壁菌门)为As污染生境中微生物优势门类并且与非专性吸附态As和谷胱甘肽含量呈正相关.更多还原

【Abstract】 In order to study the effects of arsenic pollution on microbial diversity and to find the arsenic-resistant bacteria which were beneficial to the remediation of arsenic pollution,high throughput sequencing method was used to analyze the effects of arsenic stress on soil microbial diversity and community structure in wetland habitats( the concentrations of As were set at 0,80,100,150,200 and 800mg/kg,respectively,and were marked as AT80,AT100,AT100,AT150,AT200 and AT400 correspondingly). The results showed that arsenic stress could cause changes in both microbial diversity and community structure,however,it was not a simple negative correlation.The highest number of OTU( operational taxonomic units) showed in the AT80 group and the value was 1849 which was 58. 9% higher than that of AT0 group without arsenic treatment. This indicated that low arsenic stress might stimulate the growth and reproduction of arsenic-sensitive microorganisms,such as Desulfovibrio and Allobaculum,which made the community structure more complex and diverse.High concentration of arsenic(400 mg/kg) significantly inhibited microbes,resulting in the extinction of some species and the decrease of diversity. Arsenic pollution could induce arsenic-resistant microorganisms such as Pseudomonas to become dominant groups,and the community structure tended to be stable and single. The microbial community structure had obvious response characteristics to different arsenic pollution stresses and could be used as a sensitive index for soil quality evaluation of arsenic contaminated wetlands. There were alarge number of Pseudomonas veronii in the AT400 group,which could be used as a reference for microbial remediation of arsenic contaminated wetland. The results showed that microbes were sensitive to arsenic pollution,and Proteobacteria and Firmicutes were the dominant species of microorganisms in arsenic-polluted habitat and were positively correlated with non-specific adsorbed arsenic and glutathione.更多还原