Figure 4

Alteration of the surface of the chondrite meteorite NWA 1172 slabs mediated by M. sedula. (a) Secondary electron (SE) image of a NWA 1172 slab cultivated with M. sedula at 73 °C. (b) Magnified SE image of a NWA 1172 slab cultivated with M. sedula at 73 °C. (c) SE image of abiotically exposed slab of NWA 1172 to the cultivation medium at 73 °C. (d) Magnified area of SE image of NWA 1172 slab cultivated with M. sedula at 73 °C. (e) EDS spectra of globular structures (marked with red A) that form iron oxides aggregates, containing mainly Fe and P. (f) EDS spectra of branched network of crystalline iron oxides (marked with red b). Arrows indicate the areas where crystalline iron oxides occur.