In deserts and other arid lands, microbes often form very thin top layers on soil known as biocrusts, which behave a bit like Rip Van Winkle. He removed himself from a stressful environment by sleeping for decades, and awoke to a changed world; similarly, the biocrust’s microbes lie dormant for long periods until precipitation (such as a sudden downpour) awakens them. Understanding more about the interactions between the microbial communities—also called “microbiomes”—in the biocrusts and their adaptations to their harsh environments could provide important clues to help shed light on the roles of soil microbes in the global carbon cycle.(more…)
Berkeley Lab Researchers Find Little Correlation Between Microbial Gene Expression and Environmental Conditions in the Laboratory
A new study challenges the orthodoxy of microbiology, which holds that in response to environmental changes, bacterial genes will boost production of needed proteins and decrease production of those that aren’t. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) found that for bacteria in the laboratory there was little evidence of adaptive genetic response. In fact, most bacterial genes appear to be regulated by signals unrelated to their function.
“Gene regulation in bacteria is usually described as an adaptive response to an environmental change so that genes are expressed only when they are required, but we’ve shown that in the laboratory gene regulation is often maladaptive,” says Adam Arkin, a systems and synthetic biologist and director of Berkeley Lab’s Physical Biosciences Division. “From our results, we propose that most bacterial genes are under indirect control, which means their expression is a response to signals not directly related to their function, and that their regulatory mechanisms perform poorly in the artificial conditions of a laboratory.” (more…)
