Kinner N E, Harvey R W, Blakeslee K, Novarino G, Meeker L D
Environmental Research Group, University of New Hampshire, Durham 03824, USA.
Appl Environ Microbiol. 1998 Feb;64(2):618-25. doi: 10.1128/AEM.64.2.618-625.1998.
Time series incubations were conducted to provide estimates for the size selectivities and rates of protistan grazing that may be occurring in a sandy, contaminated aquifer. The experiments involved four size classes of fluorescently labeled groundwater bacteria (FLB) and 2- to 3-microns-long nanoflagellates, primarily Spumella guttula (Ehrenberg) Kent, that were isolated from contaminated aquifer sediments (Cape Cod, Mass.). The greatest uptake and clearance rates (0.77 bacteria.flagellate-1.h-1 and 1.4 nl.flagellate-1.h-1, respectively) were observed for 0.8- to 1.5-microns-long FLB (0.21-microns3 average cell volume), which represent the fastest growing bacteria within the pore fluids of the contaminated aquifer sediments. The 19:1 to 67:1 volume ratios of nanoflagellate predators to preferred bacterial prey were in the lower end of the range commonly reported for other aquatic habitats. The grazing data suggest that the aquifer nanoflagellates can consume as much as 12 to 74% of the unattached bacterial community in 1 day and are likely to have a substantive effect upon bacterial degradation of organic groundwater contaminants.
进行了时间序列培养，以估算在受污染的砂质含水层中可能发生的原生生物捕食的大小选择性和速率。实验涉及四类大小的荧光标记地下水细菌（FLB）和2至3微米长的纳米鞭毛虫，主要是从受污染的含水层沉积物（马萨诸塞州科德角）中分离出的古氏泡沫虫（Ehrenberg）肯特。对于0.8至1.5微米长的FLB（平均细胞体积为0.21微米³），观察到最大摄取率和清除率（分别为0.77个细菌·鞭毛虫⁻¹·小时⁻¹和1.4纳升·鞭毛虫⁻¹·小时⁻¹），这些FLB代表受污染含水层沉积物孔隙流体中生长最快的细菌。纳米鞭毛虫捕食者与首选细菌猎物的体积比为19:1至67:1，处于其他水生生境通常报道范围的下限。捕食数据表明，含水层中的纳米鞭毛虫在1天内可消耗多达12%至74%的未附着细菌群落，并且可能对地下水中有机污染物的细菌降解产生实质性影响。
