水环境中微小细菌的分布及生态作用研究进展

Distribution and ecological role of small bacteria in aquatic environments——a review

由于微生物本身的生理特性及现有检测方法的限制,自然界中大部分细菌不能被传统微生物工具所观察,这类微小细菌被称之为"看不见的主体(Unseen majority,USM)",在大多数天然水环境中营养物浓度较低,微小细菌(USM)占有主导优势,具有重要的生态作用。但是,微小细菌对传统富营养培养基比较敏感,且生物体积微小(小于0.1μm3),难以被传统培养基所检测分离,人们对其认识仍然很局限。总结关于微小细菌的一些特性概念,概括微小细菌的检测和培养方法及在水环境中的分布情况,进一步讨论其生态作用及应用,最后对微小细菌的生理及其在水质评价中的应用等方面进行展望。

Due to the fundamental physiology and current limits in detection methods, the majority of microorganisms, so-called ＂unseen majority（USM）＂, in the natural world are not accessible using traditional microbiological tools. Small USM bacteria are dominant and have significant ecological functions in most aquatic environments, where nutrient concentrations are low. As they are sensitive to conventional high nutrient media and have small bio-volumes（less than 0.1 μm^3）, small bacteria often escape traditional cultivation attempts and are therefore still poorly described. In this review,the concepts relating to the characterization of small cells are compared. We also review the cultivation and detection methods and the distribution of small bacteria in aquatic environments,followed by in-depth discussion of the ecological functions of small bacteria. Finally, the future prospects of USM bacteria are discussed in terms of their growth physiology and applications in water quality evaluation.