| 摘要: |
| 为研究重金属污染土壤经不同生态类型蚯蚓消化后蚓粪和消化前土壤的微生物群落结构差异,选取2种不同污染特征的重金属污染水稻土,分别接种表栖型赤子爱胜蚓Eisenia fetida和内栖型壮伟环毛蚓Amynthas robustus进行10 d室内盆钵培养后采集新鲜蚓粪,通过变性梯度凝胶电泳技术和序列分析研究蚓粪和对照土壤的微生物种群特征。蚓粪微生物丰富度和Shannon指数均明显高于对照土壤(P<0.05),微生物群落结构发生变化,但2种蚓粪间微生物多样性指数无显著差异,群落结构具有一定的相似性。对蚓粪处理的优势条带进行序列分析发现,主要的优势菌群有:香味菌属(Myroides sp.)、芽孢杆菌属(Bacillus sp.)、鞘氨醇杆菌属(Sphingobacterium sp.)、金黄杆菌属(Chryseobacterium sp.)、假单胞杆菌属(Pseudomonas sp.)、丛毛单胞菌属(Comamonas sp.)、不动杆菌属(Acinetobacter sp.)以及不可培养细菌。蚯蚓取食重金属污染土壤消化后产生的蚓粪微生物群落结构发生变化,种群多样性更为丰富;不同生态类型蚯蚓间的蚓粪微生物群落有一定的相似性,其优势菌群大多为与金属迁移转化相关的菌群。 |
| 关键词: 重金属污染 蚯蚓 新鲜蚓粪 微生物种群结构 优势菌群 |
| DOI：10.11841/j.issn.1007-4333.2015.05.13 |
| 投稿时间：2015-01-14 |
| 基金项目:中国博士后科学基金项目(2012M511819);国家自然科学基金青年科学基金项目(41201305);广东省自然科学基金博士启动项目(S2012040007806);高等学校博士学科点专项科研基金(20124404110022) |
|
| Effects of earthworm gut on microbial community structure in heavy metal contaminated soils |
|
DAI Jin-jun1, ZHANG Chi1, ZHOU Bo1, SUN Ying-tao2, HUANG Yu-ting1, REN Zong-ling1, DAI Jun1
|
| (1.College of Resources and Environment/Guangdong Province Key Laboratory of Land use and consolidation/Key Laboratory of the Ministry of Land and Resources for Construction Land Transformation/Key Laboratory of Arable Land Conservation in South China of Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, China;2.Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China) |
| Abstract: |
| Microbial community structures in undigested soil and earthworm casts collected after digestion were studied by inoculating earthworms of two different ecological species in two heavy metal contaminated paddy soils. Eisenia fetida (epigeics) and Amynthas robustus (anecics) were inoculated in soils for 10 days under lab condition,and then fresh earthworm casts were sampled by gut purging at 23℃.The microbial community structures in earthworm casts and undigested soil were analyzed by PCR-DGGE and cloning techniques.Higher microbial diversity and Shannon index were found in fresh earthworm casts than in undigested soil (P<0.05).But no significant difference in microbial community structure was found between the casts from different earthworms species.By gel cutting and sequencing and blast comparison,Myroides sp.was found in both earthworm casts in soils contaminated by acid mining drainage.Bacillus sp.and Sphingobacterium sp. were observed in the casts from E.foetida as its unique predominant strains,while Chryseobacterium sp.was only found in the casts from A.robustus.Pseudomonas sp.and Comamonas sp. were found in both earthworm casts in alkaline soil contaminated by waste water from Pb/Zn mine;Acinetobacter sp.was found in the casts from E.foetida;Chryseobacterium sp.and Sphingobacterium sp.were found in the casts from A.robustus as the predominant strains.All the dominant microbial species existed in casts were the bacteria with high tolerance to heavy metal.Earthworm digestion strongly affected bacterial community structure in heavy metal contaminated soils.Microbial diversity was significantly increased by earthworm digestion,but casts from different earthworm species had almost similar microbial communities.The observed dominant bacteria species are more capable of tolerating heavy metal stress. |
| Key words: polymetals pollution earthworm fresh earthworm casts microbial communities predominant strains |
