Lots of bacteria can grow in the seemingly unfriendly environment under glaciers , a region formerly considered free of much biology. This finding by glaciologists working in Switzerland could help solve some puzzles of the last ice age and point the way for finding life on other planets. Bacteria with odd lifestyles have been under increasing study lately, with most research focused on the species which prefer hot homes. The new study shifts attention to the other end of the thermometer . The exciting thing is the idea of pushing the window of acceptable bacterial environments a little bit farther open. Researchers have previously collected small numbers of bacteria from ice in Antarctica and Greenland, but they could not determine whether these were active bacteria or just frozen cells blown in by wind. In contrast, the earth beneath two Swiss glaciers harbors large colonies of bacteria--hundreds of millions of cells per gram--that appear to be growing at 0degC. Scientists followed upon these findings by taking samples of ice, water, and earth at two mountain glaciers. They found that earth beneath the glaciers contained much larger populations of bacteria than did surface and inner part of ice. Those findings indicate that the bacteria were growing at the bottom of the glacier and are not something washed in while the scientists drilled through the ice. Looking at the bacteria under a microscope , the researchers found that many were in the process of dividing, and healthy under the ice. The bacteria might break down minerals and plant remains originally buried beneath the glacier or later washed in by water going slowly through the ice, scientists say. "Some of the assumptions we have made in the past now must be seriously questioned," say researchers. "If bacteria can live under glaciers on Earth, why not on other planets? The new study points out in many ways that the bottoms of glaciers are probably quite good environments from the point of view of bacteria. So, maybe the bottom of the ice sheets on other planets would be a sensible place to try if you're going to look for life on them." What is special about the new study on bacteria?
It focuses on the bacteria in hot environments. It opens the windows of the bacterial labs wider. It pays more attention to the bacteria in the thermometer. It changes scientists' view about the environment bacteria exist in.