%0 Journal article
%A Heim, Christine
%A Quéric, Nadia-Valérie
%A Ionescu, Danny
%A Schäfer, Nadine
%A Reitner, Joachim
%T Frutexites-like structures formed by iron oxidizing biofilms in the continental subsurface (Äspö Hard Rock Laboratory, Sweden)
%R 10.1371/journal.pone.0177542
%R 10.23689/fidgeo-2397
%J PLOS ONE
%V 12
%N 5

%X Stromatolitic iron-rich structures have been reported from many ancient environments and are often described as Frutexites, a cryptic microfossil. Although microbial formation of such structures is likely, a clear relation to a microbial precursor is lacking so far. Here we report recent iron oxidizing biofilms which resemble the ancient Frutexites structures. The living Frutexites-like biofilms were sampled at 160 m depth in the Äspö Hard Rock Laboratory in Sweden. Investigations using microscopy, 454 pyrosequencing, FISH, Raman spectroscopy, biomarker and trace element analysis allowed a detailed view of the structural components of the mineralized biofilm. The most abundant bacterial groups were involved in nitrogen and iron cycling. Furthermore, Archaea are widely distributed in the Frutexites-like biofilm, even though their functional role remains unclear. Biomarker analysis revealed abundant sterols in the biofilm most likely from algal and fungal origins. Our results indicate that the Frutexites-like biofilm was built up by a complex microbial community. The functional role of each community member in the formation of the dendritic structures, as well as their potential relation to fossil Frutexites remains under investigation.
%U http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/6710
%~  FID GEO-LEO e-docs