Communities that thrive in extreme conditions captured from a freshwater lake

Organisms that can grow in extreme conditions would be expected to be confined to extreme environments. However, we were able to capture highly productive communities of algae and bacteria capable of growing in acidic (pH 2), basic (pH 12) and saline (40 ppt) conditions from an ordinary freshwater lake. Microbial communities may thus include taxa that are highly productive in conditions that are far outside the range of conditions experienced in their host ecosystem. The organisms we captured were not obligate extremophiles, but were capable of growing in both extreme and benign conditions. The ability to grow in extreme conditions may thus be a common functional attribute in microbial communities.通常认为，可在极端条件下生长的生物仅局限于极端环境之中。然而，我们从一处普通淡水湖泊中，获取到可在酸性（pH 2）、碱性（pH 12）及盐度40 ppt条件下高效生长的藻类与细菌群落。由此可见，微生物群落中可能包含在远超出其原生生境生态系统常规条件范围的极端生境下仍具备高生产力的分类类群。本次研究获取的微生物并非专性极端微生物，它们既能在极端环境中生长，也可在温和条件下存活。因此，在极端条件下生长的能力或许是微生物群落中普遍存在的一类功能属性。