Stars of the terrestrial deep subsurface: a novel 'star-shaped' bacterial morphotype from a South African platinum mine.

We study structure and function. Credit of course, goes to TJB, for it is from him that I inherited the habit of personifying bacteria and attempting to think like a bacterium, to better understand what they do. This work has taken us to wonderful places such as Yellowstone National Park, The Canadian Arctic, Australia, and the deep subsurface in the Republic of South Africa, the subject of this manuscript. From their perspective, why they do what they do is simple, to live. How they do it, is more challenging for us to understand, so it is something that we continue to work on. The marvel of bacteria is something that I, in turn, try to pass on to my students where I hope it will find fertile ground and provide as much enjoyment as it has given me - G. Southam. A biofilm (mine-slime) collected from the Northam Platinum mine in the Republic of South Africa contained a new bacterial morphotype. Mine-slimes are generally considered to be microbiologically compromised, subsurface samples due to the likelihood of contamination from the mining environment. However, careful examination of this biofilm demonstrated that it possessed a diverse bacterial population that included organisms that are consistent with the deep subsurface, suggesting that mine-slimes represent an underutilized, 'natural' bacterial enrichment. Using scanning and transmission electron microscopy, a novel, branching, filamentous, star-shape bacterium (in cross section) has been found, adding a new bacterial morphotype and strategy that bacteria have demonstrated to increase their surface area to volume ratio.