Biomarkers in Antarctic Microbial Mats
A study of benthic microbial mats from an ice-covered lake in Antarctica is helping astrobiologists better understand bacteriohopanepolyols (BHPs). These membrane lipids serve as a marker for biology and environmental conditions. According to the researchers, degradation products from BHPs (specifically 2‐methylhopanes) are considered some of the oldest (and most prevalent) taxonomically informative biomarkers in sedimentary rocks.
The team examined the sources, physiological roles, and preservation of BHPs from microbial mats in Lake Vanda, located in Antarctica’s McMurdo Dry Valleys. The study is the first to examine how the production of this important biomarker is regulated in a polar, high-altitude environment. Cyanobacteria appear to be the source of 2-MeBHP in the mats, and the authors discuss whether or not the production of 2-MeBHP is tied to solar irradiance.
The study, “Bacteriohopanepolyols across environmental gradients in Lake Vanda, Antarctica,” was published in the journal Geobiology. The work was supported by NASA Astrobiology through the Exobiology Program.