基于16S rDNA-DGGE和FDC技术对富营养化湖泊不同生态修复工程区细菌群落结构的研究

Bacterial Community Structure in Different Eco-restoration Areas in a Eutrophic Lake Based on 16S rDNA-DGGE and FDC

于2005年10月在太湖梅梁湾水体生态修复工程区中采集不同生物净化区水样,直接提取水样中的总DNA,以细菌16SrDNA通用引物进行V3区PCR扩增,PCR产物经DGGE(变性凝胶梯度电泳)分离后,获得水体细菌群落的16S rDNA指纹图谱;并运用FDC(表面荧光直接计数)方法对不同生物净化区的细菌丰度进行了测定.结果表明,随着净化处理程度的增加,细菌群落多样性呈现上升趋势,DGGE条带从未实施生态修复的梅梁湾中的13条上升到沉水植物恢复区的25条;细菌数量的变化则呈现显著下降趋势,由工程区外围(重富营养区)的5.36×106cells/mL下降到生态修复区的2.06×106cells/mL.生态修复工程的实施改善了水体的生境条件,提高了水体的自净能力,促进了细菌多样性的恢复.

Water samples were collected in different ecological restoration areas in Feb of 2005, and genomic DNA was extracted by using SDS-CTAB. The PCR amplification of the extracted microbial 16S rDNA gene fragments was done using primers GC341F and 518R. The result of agarose gel （ 1.2% ） electrophoresis showed that the PCR products were about 230 bp in length. Using PCR products, DGGE was performed on a DGGE analyzer with 8% （w/V） loading acrylamide （38：1, acrylamide：bisacrylamide） gel under 35% ～55% linear gradient of denaturant, and the abundance of bacteria was observed by epiftuorescence direct counting. The results showed that both the bacterial community and abundance changed in different ecological restoration areas. After the implementation of engineering measures, the community diversity of bacteria increased, and the main bands of DGGE representing the diversity of bacterial species added 12 from un-restoration areas to eco-restoration areas. However, the abundance of bacteria decreased from 5.36 ×10^6 cells/mL to 2.06×10^6 cells/mL. After two years＇ ecological restoration, the water quality was improved obviously, which made the bacterial community diversity increased. Fig 6, Tab 1, Ref 40