PD Dr Tillmann Lueders

Event Date: 
Tuesday, October 31, 2017 - 19:15 - 19:45
Helmholtz Zentrum Munich

Snot or not: Functional microbiome dissection of massive methane-fueled biofilms discovered in an iodine-rich spring cavern


Massive biofilms have recently been discovered in the cave of a former medicinal spring, already mentioned due to its high iodine content by the famed chemist Justus von Liebig in the 19th century. The biofilms completely cover the walls and ceilings of the cave, giving rise to speculations about their metabolism and the main drivers of biofilm formation. We address these questions using tools of geochemistry, biofilm imaging and molecular microbiome dissection. Although the cave is situated just several meters below the surface, microbial communities largely independent from surface carbon and energy inputs were discovered. Stable isotope analysis indicated that thermogenic methane emerging into the cave along with iodine-rich formation water served as important driver of biofilm formation. Biofilm microbiota were surprisingly diverse, with a host of populations closely related to well-known methanotrophs, methylotrophs, and also potentially iodine-cycling bacteria. Evidence is provided that the massive EPS production observed could serve as an electron sink for methylotrophs, as well as a protective barrier against possible toxic iodine species in the cave. This research shows that cave ecosystems can provide us with important glimpses into the potentially unique biogeochemical processes ongoing below our feet.
Karwautz C, Kus G, Stockl M, Neu TR, Lueders T (2017) Microbial megacities fueled by methane oxidation in a mineral spring cave. ISME J doi: 10.1038/ismej.2017.146