Genomic factors contributing to the upper temperature growth limits of bacteria

点击翻译按钮获取中文摘要

All living organisms have an upper temperature limit to their growth. Throughout earth's history there have been several shifts in its average temperature, but the current climate change may be one of the fastest warming cycles since the Paleocene-Eocene Thermal Maximum which occurred about 60 M years ago. Organisms on earth will have to adapt to these changes, and many will evolve a greater resistance to heat. *** In this proposal we examine some of the heat adaptations that bacteria use. In a laboratory series of experiments we previously found evidence that one mechanism bacteria use to adapt to a lethal temperature is to increase the expression of a thermo-labile protein. This is accomplished by changing the rate that the protein is translated from the messenger RNA. Another presumed mechanism is that another, unknown protein, that helps preserve the integrity of thermo-labile proteins, is made in larger amounts, and the end result is that thermo-labile proteins effectively have longer half-lives. In the proposed research we will determine if increased protein translation and other mechanisms play an important role in the adaptation of bacteria to higher temperatures. *** The knowledge gained from the proposed research will contribute to our understanding of adaptation to warmer temperatures. In addition the results will help guide laboratory-evolution of temperature-resistant bacteria used in bio-manufacturing. Importantly, thermo-resistance often correlates with resistance to industrially-produced chemicals, such as alcohols, and our research may help to create bacteria that can withstand higher concentrations of the bio-fuels that they produce.