二氧化碳入侵土壤包气带对微生物群落的影响  

Effect of carbon dioxide permeation into soil's unsaturated layer on the microbial community

作　　者：张慧慧[1] 李春荣[1] 邓红章[1] 张徽[2] 李发明[1] 张帆[1] 

机构地区：[1]旱区地下水文与生态效应教育部重点实验室长安大学环境科学与工程学院,西安710054 [2]中国地质调查局水文地质环境地质调查中心,河北保定071051

出　　处：《安全与环境学报》2016年第2期377-381,共5页Journal of Safety and Environment

基　　金：国家自然科学基金项目(41302207);中国地质调查项目(12120113006400);陕西省自然科学基金项目(2014JM5212)

摘　　要：为探讨地质封存CO_2泄漏对土壤微生态环境的影响,以中国青海省西宁市平安县三合镇天然CO_2泄漏试验场土壤为研究对象,采用活菌计数法测定不同物质的量比CO_2试验区土壤微生物的菌落数目,应用PCR-DGGE(Denaturing Gradient Gel Electrophoresis)和16S r DNA文库技术对样品的细菌和真菌群落结构及遗传多样性进行分析。结果表明:当CO_2物质的量比由600μmol/mol增加到23 000μmol/mol时,土壤细菌、真菌数量明显增加,而放线菌数量显著减少;各试验区细菌和真菌多样性指数(H)、丰度(S)有所不同,土壤真菌多样性变化高于细菌;高物质的量比CO_2对真菌Geomyces sp.、根瘤菌unclassified_Rhizobiales等菌群的生长产生刺激作用,但对unclassified-Actinobacteria(放线菌群)、Sphingomonas sp.(鞘氨醇单胞菌属)等菌群的生长有抑制作用;3 010μmol/mol CO_2对真菌Ascomycota sp.(子囊菌门)、Phoma medicaginis(茎点霉)产生了较强的毒性,使之不能正常生长繁殖。研究表明:高物质的量比CO_2入侵土壤包气带对微生物群落多样性影响较大,主要表现为原有细菌、真菌数量的丰富或被削弱,或部分物种的消失及新物种的出现,但其主要建群种未变;对根瘤菌等菌群生长的刺激作用可能使土壤固氮能力提高;不同物质的量比CO_2入侵下土壤细菌群落相似性系数远大于真菌,即真菌对CO_2胁迫表现更为敏感,真菌Ascomycota sp.及Phoma medicaginis有望成为地质封存CO_2泄漏微生物监测与甄别的指示菌种。The paper is oriented to present the study results on the effects of carbon dioxide permeation into the soil＇s unsaturated layer on the microbial environment with its study samples collected from the town of Sanhe,Ping＇an County under Xining City,Qinghai. In the paper,we have managed to identify the amount of the soil microbes with the viable counting method by analyzing the microbial community structure and the genetic diversity of the soil bacteria and fungi with the PCR- DGGE fingerprint and 16 S r DNA library technology. The results of our study show that when the concentration of CO_2 in the soil has increased from 600 μmol / mol to 23 000 μmol / mol,both the soil bacteria and the soil fungi tend to increase significantly whereas that of the soil actinomycosis tends to fall. Greater CO_2 concentration can help to stimulate the growth of some microorganisms,such as Geomyces sp.,unclassified-Rhizobiales etc.,whereas it can also inhibit other bacteria,such as unclassified-Actinobacteria and Sphingomonas sp. What is more,when CO_2 reaches the extent of 3 010 μmol / mol in the soil,Phoma medicaginis may turn to be strongly toxic,it may impede the regular growth of Ascomycota sp. and Phoma medicaginis. The research results also help to find that higher concentration of CO_2 tends to produce strong impact on the diversity of the soil＇s microbial environment,thus leading to the increase of some original bacteria and fungi or reduction,or disappearance of some other originally existing species,or resulting in some other novel species,though the dominant species may remain constant. On the other hand,since the elevated CO_2 levels can stimulate the growth of Rhizobium,it may also have a stimulating effect on the nitrogen-fixing capability of the soil. In spite of such changes likely to occur to the soil,the original coefficient of the similarity in the soil bacteria community tends to be much greater and tighter than the difference in the fungi,i. e.,the fungi themselves prove to be more sensitive to the elev

关 键 词：环境工程学 二氧化碳 土壤包气带 微生物群落结构 遗传多样性 PCR-DGGE 

分 类 号：X172[环境科学与工程—环境科学]