铜锈环棱螺（Bellamya aeruginosa）生物扰动对藻华水体沉积物微生物群落结构的影响

摘要

Phospholipid fatty acids （PLFAs） were applied to determine changes in microbial community structures af- fected by the bioturbation ofBellamya aeruginosa. The results showed that the total biomass of PLFAs had a distinguished increase in treatments contained snails comparing with the control group. Furthermore, it was highly related to the content of TOC, r = 0.541 （P〈0.05）. The ratio of bacteria/fungus changed remarkably during the experiment, the ratio of bacte- ria/fungus in mid-density treatment is significantly higher than the other treatments （P〈0.05）, indicating that bacteria grew more quickly than fungus and the bacteria biomass increased significantly in Mid-density condition. Principle components analysis （PCA） of PLFAs profiles demonstrated that the microbial community structures were similar in low and high density treatments and the control, and no obvious changes were observed; while in Mid-density treatments （196ind/m2）, microbial community structures had varied apparently.%应用磷脂脂肪酸（PLFAs）法测定了不同密度铜锈环棱螺生物扰动下沉积物表层微生物群落结构的变化。结果表明，与对照组相比，含螺处理组PLFAs总生物量有了明显的升高，且与底泥总有机碳（TOC）含量变化趋势有很高的相关性（r=0．541）（P〈0．05）。实验过程中细菌／真菌值发生显著变化，中密度处理组的细菌／真菌值显著高于其它实验组（P〈0．05），说明中密度螺影响下细菌生长较真菌更快，细菌生物量显著升高。主成分分析（PCA）显示，低、高密度螺处理下沉积物的微生物群落结构与对照组相似，而中密度螺处理组（3个螺／培养柱）（相当于196ind／m2）能够使沉积物微生物群落结构产生明显变化。