浒苔腐烂过程中水体细菌群落结构变化的PCR-DGGE分析

通过生态模拟实验,利用分子生态学技术,对浒苔(Enteromorpha prolifera)腐烂过程中水体细菌群落结构的变化进行了研究。将3.0 kg完全死亡的浒苔置于容积为500 L的实验容器中,定期取水样,进行化学需氧量(COD)、溶解氧(DO)、好氧性异养菌数量测定及细菌种群结构的分析。实验结果表明,随着浒苔腐烂程度的增加,水中的DO呈逐渐减少趋势,COD和好氧性异养菌数量均呈先增加后减少的变化趋势;水体细菌主要由拟杆菌门黄杆菌纲和变形菌门α-、γ-、ε-变形菌纲的细菌组成,其优势菌群在浒苔腐烂不同时期有较大程度的改变,初期黄杆菌纲细菌为主要优势细菌,后期则以α-、γ-、ε-变形菌纲细菌为主要优势细菌。本研究结果为研究浒苔爆发对海洋环境的影响提供了理论依据。

Changes in population structure of bacteria during decomposition of Enteromorpha prolifera

We used ecological simulation to study changes in the population structure of bacteria in water during the decomposition of Enteromorpha prolifera.We placed 3.0 kg of dead E.prolifera into a 500 L glass tank and measured chemical oxygen demand(COD) and dissolved oxygen(DO).In addition,we counted the number of aerobic heterotrophic bacteria and analyzed the structure of the bacteria population at different stages using PCR-DGGE.We observed an initial increase in DO,COD,and the abundance of aerobic heterotrophic bacteria as the degree of decomposition of E.prolifera increased,followed by a decrease in COD and aerobic heterotrophic bacteria abundance.The bacterial population in the water consisted primarily of Flavobacteria(39.39%) and Pro-teobacteria(60.61%).We observed a significant change in the species structure during the decomposition process.During the initial stage of decomposition,Flavobacteria were dominant,but were replaced by α-,γ-,and ε-Proteobacteria during the latter stages of decomposition.Our results provide insight into predicting the influence of E.prolifera breakouts in marine environment.