Search for the Upper Temperature Limit of Multicellular Organisms Not Seen by Traditional Environmental Researchers (MONSTERS)

摘要

Until fairly recently, it was widely believed that the highest temperature to which life on Earth could possibly adapt was about 60 degrees Centigrade (C). Above this temperature, it was assumed, essential biomolecules would be destroyed, and life of any kind would, therefore, also be destroyed. In the last two decades, however, this assumption has been proved to be wrong. Many new species of bacteria and archaea have been discovered in a wide range of habitats that have ambient temperatures well above 60 C. These organisms, known as "thermophiles" (heat lovers), are thriving in hot springs around the world. The hottest of them are living in submarine hot springs that may reach temperatures of 113 C (hydrostatic pressure prevents boiling). The discovery of these hyperthermophilic microbes has had important scientific and practical consequences. Scientifically, it has expanded our knowledge of the diversity of organisms on Earth, and it has provided important insights into mechanisms for thermostabilization of essential biomolecules. This information is of interest to the NASA Astrobiology program goals of "establishing the limits for life in environments that provide analogues for conditions on other worlds" and "how life evolves on the molecular, organismic, and ecosystem levels."