城市纳污河流沉积物微生物群落结构特征

以南京市运粮河沉积物为研究对象,通过磷脂脂肪酸(PLFA)技术分析了不同水期城市纳污河流沉积物微生物群落结构特征。结果表明:在不同的水期运粮河沉积物微生物量出现了显著差异,温度是导致微生物量在丰、平、枯三期出现显著差异的主要因素(P<0.05);在相同水期,营养物质含量高的地方对应着高的微生物量;16:0 iso、17:0 anteiso、15:0 iso这几种PLFA所指示的革兰氏阳性菌(G+)是影响运粮河沉积物微生物群落构成的主要菌落,导致沉积物微生物群落结构出现显著差异的环境因素是水期;单不饱和/支链脂肪酸比值可以作为反映水环境系统整体营养水平的指标,在C/N比值升高时微生物会将单不饱和脂肪酸转变成环丙基或者饱和脂肪酸以适应新的环境;PLFA含量比[c(i15:0)+c(i17:0)]/[c(a15:0)+c(a17:0)]可以作为指示水环境碳素含量的标志。

On the characteristic of sediments microbial community structure of urban polluted river

The research adopts phospholipid fatty acid analysis to quantify the microbial community structure of sediments from Yunliang River in different water types during different periods. The results show the following aspects: ① the microbial biomass is significantly different in different water-stage while the temperature is the dominant factor; ② in the same period, the nutritional content is positively correlated to the microbial biomass; ③ G+ indiated by 16:0 iso、17:0 anteiso、15:0 iso is the main microbial community that affects the sediments microbial community structure and water-stage fluctuation significantly influences the sediments microbial community structure; ④ Monounsaturated PLFAs/ branched PLFAs could reflect the nutrition status as microorganism would turn the monounsaturated PLFAs to cyclopropyl PLFAs and saturated PLFAs in order to suit the new conditions when C/N increased in sediment; ⑤ [c(i15:0)+c(i17:0)]/[c(a15:0)+c(a17:0)] can be used as the indicator of Carbon content in water environment.