摘要
采用PCR-DGGE分子指纹图谱技术比较南京市玄武湖、奠愁湖和太湖不同位置的表层沉积物微生物群落结构，研究结果表明，三湖泊沉积物微生物的16SrDNA的PCR扩增结果约为626bp，为16S rDNA V3～V5区特异性片段。玄武湖和莫愁湖表层沉积物中大约有20种优势菌群，且同一湖泊不同采样点DGGE图谱的差异性不大，细菌群落结构具有较高的相似性，而太湖样品DGGE条带的数目和位置表现出明显差异，且不同采样点图谱的差异性较大。三湖泊除具有特征性的微生物种属外，还分布约5个相同的细菌种群，可能与沉积物的理化性质和水生植被的影响相关。对DGGE图谱中7条主带进行回收、扩增和测序，结果显示其优势菌群具有不同的序列组成，其中5个序列与Genebank中已登录的细菌种群的同源性≥99％，2个序列的同源性为96％和93％，其中2个相似的细菌类群目前尚未获得纯培养。
As a new technique for DNA fingerprinting, denaturing gradient gel electrophoresis （DGGE） can be used for microbial diversity analysis in environmental samples. In this study, PCR-DGGE was applied to analyze the microbial communities in lake sediments. Sediment samples from seven locations in three lakes were collected and their genomic DNA was directly extracted. The DNA yield of sediments of Lake Xuanwu and Lake Mochou was high （ 10μg/g）, while that of sediments in Lake Taihu was relatively low. After DNA purification, the 16S rRNA genes （V3 to V5 region） were amplified with two universal primers （F341GC and R907）. These amplified DNA fragments were separated by parallel DGGE.
The DGGE profiles indicate different bands＇ patterns for different samples. There are five common bands in all lake sediment samples, which indicate that there are similarities among the populations of microorganisms that exist in all lake sediments. But, the specific bands in sediment samples indicate that the microbial communities in different lakes are different. The DGGE profiles of Lake Xuanwu and Lake Mochou are very similar and about twenty types of microorganisms are identified in the sediment samples of both lakes. These results suggest that the sediment samples of these two city lakes （Xuanwu, Mochou） have similar microbial communities. However, the DGGE profiles of sediment samples in Lake Taihu arc significant different from these two lakes.Furthermore, the DGGE profiles of sediment samples in different locations in Lake Taihu are also very different, which suggests that the microbial communities in Lake Taihu are more diversified than those in Lake Xuanwu and Lake Mochou. The differences in microbial diversity may be caused by the different environmental conditions, such as redox potential, pH, and the concentrations of organic matters, etc.
Seven major bands of 16S rDNA genes fragments from DGGE profiles of sediment samples were further eluted from gel, reamplified and sequenced. The sequences of these fragments were compared with the database in GeneBank （NCBI）. The results indicate that five sequences share 99% - 100% homology with known sequences （Bacillus and Brevibacillus, uncultured bacteria）, while the other two sequences share 96% - 93 % homology with known sequences （Acinetobacter and Bacillus）.
These results indicate that the PCR-DGGE technique combined with sequences determination is a feasible and efficient method for microbial community analysis in sediment samples.
出处
《生态学报》
CAS
CSCD
北大核心
2006年第11期3610-3616,共7页
Acta Ecologica Sinica
基金
国家"973"资助项目(2002CB412307)
国家重大水环境专项资助项目(2002AA601011)
国家自然科学基金资助项目(40371102)~~
作者简介
赵兴青（1974-），女，江苏高邮人，博士生，主要从事环境微生物生态学。
通讯作者，Corresponding author．E-mail：yangly@nju．edu．cn。
