In vitro formation of Ca-oxalates and the mineral glushinskite by fungal interaction with carbonate substrates and seawater

Abstract

Abstract. This study investigates the in vitro formation of Ca-oxalates and glushinskite through fungal interaction with carbonate substrates and seawater as a process of biologically induced metal recycling and neo-mineral formation. The study also emphasizes the role of the substrates as metal donors. In the first experiment, thin sections prepared from dolomitic rock samples of Terwagne Formation (Carboniferous, Viséan, northern France) served as substrates. The thin sections placed in Petri dishes were exposed to fungi grown from naturally existing airborne spores. In the second experiment, fungal growth and mineral formation was monitored using only standard seawater (SSW) as a substrate. Fungal growth media consisted of a high protein/carbohydrates and sugar diet with demineralized water for irrigation. Fungal growth process reached completion under uncontrolled laboratory conditions. The newly formed minerals and textural changes caused by fungal attack on the carbonate substrates were investigated using light and scanning electron microscopy (SEM-EDX), x-ray diffraction (XRD) and Raman spectroscopy. The fungal interaction and attack on the dolomitic and seawater substrates resulted in the formation of Ca-oxalates (weddellite CaC 2 O 4 ·2(H 2 O), whewellite (CaC 2 O 4 ·(H 2 O)) and glushinskite MgC 2 O 4 ·2(H 2 O) associated with the destruction of the original hard substrates and their replacement by the new minerals. Both of Ca and Mg were mobilized from the experimental substrates by fungi. This metal mobilization involved a recycling of substrate metals into newly formed minerals. The biochemical and diagenetic results of the interaction strongly marked the attacked substrates with a biological fingerprint. Such fingerprints are biomarkers of primitive life. The formation of glushinskite is of specific importance that is related, besides its importance as a biomineral bearing a recycled Mg, to the possibility of its transformation through diagenetic pathway Correspondence to: K. Kolo (kakolo@vub.ac.be) into an Mg carbonate. This work is the first report on the in vitro formation of the mineral glushinskite through fungal interaction with carbonate and seawater substrates. Besides recording the detailed Raman signature of various crystal habits of Mg-and Ca-oxalates, the Raman spectroscopy proved two new crystal habits for glushinskite. The results of this work document the role of microorganisms as metal recyclers in biomineralization, neo-mineral formation, sediment diagenesis, bioweathering and in the production of mineral and diagenetic biomarkers. They also reveal the capacity of living fungi to interact with liquid substrates and precipitate new minerals.

Raman investigation of the patina layers on Hungarian copper ingots from a fifteenth century shipwreck

“…of the oxalates as stated by Gadd . Formation of secondary minerals due to the biological attack is well documented . In dependence on environment, the production of Ca, Mg, or Cu‐oxalates can be observed, and a substantial collection of data indicate that the application of Raman spectroscopy provides reliable discrimination between the species.…”

“…Formation of secondary minerals due to the biological attack is well documented . In dependence on environment, the production of Ca, Mg, or Cu‐oxalates can be observed, and a substantial collection of data indicate that the application of Raman spectroscopy provides reliable discrimination between the species. Also, the formation of jarosite and covellite on chalcopyrite surfaces is well documented with the use of Raman analysis, in view of the resulting passivation during bioleaching of primary copper ores.…”

Experimental calcium-oxalate crystal production and dissolution by selected wood-rot fungi

“…The in vitro formation of CaOx crystals has been reported for ectomycorrhizal fungi (Graustein et al, 1977;Tuason and Arocena, 2009), airborne fungi (Mucorales; Kolo and Claeys, 2005), and biotrophic parasitic fungi (Rio et al, 2008). Studies concerning wood-decaying fungi are also plentiful.…”

Three-dimensional Magnetic Resonance Imaging of fossils across taxa

“…Palaeontological investigations, specifically, could profit from comparative studies including extant species, thereby complementing the existing knowledge with anatomical and dynamic details concerning processes like post mortem tissue decay (Weigelt, 1927) and in vivo cellular metabolic activities like biomineralisation (e.g. Freytet et al, 1996;Levi et al, 1998;Kolo and Claeys, 2005) as well as embryological development (Xiao, 2002), amber formation (Schmidt and Dilcher, 2007) or locomotion (Gatesy et al, 1999). For all these applications, suitable MR techniques are now in place (e.g.…”