University of Georgia Marine Institute, Sapelo Island, Georgia 31327.
Appl Environ Microbiol. 1987 May;53(5):958-65. doi: 10.1128/aem.53.5.958-965.1987.
We have developed a procedure for preparing monodispersed, fluorescently labeled bacteria (FLB), which may be used to measure virtually instantaneous rates of protozoan bacterivory in natural waters. FLB can be prepared both from natural bacterioplankton assemblages and from clonal isolates and can be stored in frozen suspension or freeze-dried without apparent loss of fluorescence intensity. They are not toxic to protozoa and can be metabolized to support bacterivorous protozoan growth rates equal to those on the same strain of unstained, viable bacteria. In experiments comparing uptake of FLB with uptake of fluorescent latex microspheres by protozoan assemblages in a salt marsh tidal creek, we found that both pelagic oligotrichous ciliates and phagotrophic flagellates ingested FLB with a frequency 4- to 10-fold greater than they ingested the microspheres. Consequently, it appears that the use of latex microspheres leads to underestimation of protozoan bacterivory and that the FLB technique is superior for estimating instantaneous rates of in situ protozoan grazing on bacterioplankton.
我们已经开发出一种制备单分散荧光标记细菌 (FLB) 的方法，该方法可用于测量天然水中原生动物细菌吞噬的几乎瞬时速率。FLB 既可以从天然细菌浮游生物组合中制备，也可以从克隆分离物中制备，并可以在冷冻悬浮液或冷冻干燥中储存，而荧光强度没有明显损失。它们对原生动物无毒，并且可以被代谢以支持细菌吞噬原生动物的生长速率，与相同菌株的未染色、有活力的细菌相同。在比较盐沼潮汐溪中浮游寡毛类纤毛虫和吞噬性鞭毛虫原生动物组合对 FLB 和荧光乳胶微球的摄取的实验中，我们发现，FLB 的摄取频率比微球高 4 到 10 倍。因此，似乎使用乳胶微球会导致对原生动物细菌吞噬作用的低估，而 FLB 技术更适合估计原位原生动物对细菌浮游生物的瞬时摄食率。
