Frutexites-like structures formed by iron oxidizing biofilms in the continental subsurface (Äspö Hard Rock Laboratory, Sweden).
Christine HeimNadia-Valérie QuéricDanny IonescuNadine SchäferJoachim ReitnerPublished in: PloS one (2017)
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.
Keyphrases
- candida albicans
- microbial community
- high resolution
- pseudomonas aeruginosa
- staphylococcus aureus
- biofilm formation
- raman spectroscopy
- iron deficiency
- antibiotic resistance genes
- healthcare
- cystic fibrosis
- optical coherence tomography
- mental health
- risk assessment
- high throughput
- mass spectrometry
- high speed
- amino acid
- human health
- data analysis