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

Abstract

a b s t r a c tTwenty-six species of white-rotting Agaricomycotina fungi (Basidiomycota) were screened for their ability to produce calcium-oxalate (CaOx) crystals in vitro. Most were able to produce CaOx crystals in malt agar medium in the absence of additional calcium. In the same medium enriched with Ca 2þ , all the species produced CaOx crystals (weddellite or whewellite). Hyphae of four species (Ganoderma lucidum, Polyporus ciliatus, Pycnoporus cinnabarinus, and Trametes versicolor) were found coated with crystals (weddellite/whewellite). The production of CaOx crystals during the growth phase was confirmed by an investigation of the production kinetics for six of the species considered in the initial screening (Pleurotus citrinopileatus, Pleurotus eryngii, Pleurotus ostreatus, P. cinnabarinus, Trametes suaveolens, and T. versicolor). However, the crystals produced during the growth phase disappeared from the medium over time in four of the six species (P. citrinopileatus, P. eryngii, P. cinnabarinus, and T. suaveolens). For P. cinnabarinus, the disappearance of the crystals was correlated with a decrease in the total oxalate concentration measured in the medium from 0.65 mg mm À2 (at the maximum accumulation rate) to 0.30 mg mm À2. The decrease in the CaOx concentration was correlated with a change in mycelia morphology. The oxalate dissolution capability of all the species was also tested in a medium containing calcium oxalate as the sole source of carbon (modified Schlegel medium). Three species (Agaricus blazei, Pleurotus tuberregium, and P. ciliatus) presented a dissolution halo around the growth zone. This study shows that CaOx crystal production is a widespread phenomenon in white-rot fungi, and that an excess of Ca 2þ can enhance CaOx crystal production. In addition, it shows that some white-rot fungal species are capable of dissolving CaOx crystals after growth has ceased. These results highlight a diversity of responses around the production or dissolution of calcium oxalate in white-rot fungi and reveal an unexpected potential importance of fungi on the oxalate cycle in the environment.

Firing Range Soils Yield a Diverse Array of Fungal Isolates Capable of Organic Acid Production and Pb Mineral Solubilization

“…T. versicolor has also been studied for the same purpose (12), as well as for bioremediation of polycyclic aromatic hydrocarbons (46). A recent study of T. versicolor examined the organism's capacity to form calcium oxalate and indicated even higher levels of oxalic acid than were observed in our study (23).…”

“…Raw fungal 28S rRNA gene sequences were trimmed and quality checked using MOTHUR (49a). MOTHUR was also used for preclustering at 2%, rarefaction curves, distance calculations, clustering, and further analysis based on operational taxonomic units (OTUs) (23). Fungal sequences were classified by their top BLAST hit compared against the SILVA LSU database in MG-RAST (34a) for each representative OTU.…”

Role of Fungi in the Biomineralization of Calcite

“…Typical fungal activities that can decrease alkalinity are heterotrophic respiration leading to an increase in pCO 2 , production of organic acids and excretion of H + during fungal thigmotropism [74]. In contrast, typical fungal activities that can increase carbonate alkalinity are water consumption (e.g., through translocation within the fungal network), physicochemical degassing of fungal respired CO 2 , organic acid oxidation [75,76], urea mineralization [77,78] and nitrate assimilation [79].…”

Synthesis of calcium oxalate trihydrate: New data by vibrational spectroscopy and synchrotron X-ray diffraction

“…Due to its thermodynamical instability, COT is less common than COM (monoclinic), the most table form, and than COD (tetragonal). COM and COD are major constituents of human urinary stones [5] and are found also in many organisms such as fungi, lichens, plants [6][7][8] and in rock weathering processes by lichens [9]. COT has been rarely found in urine and in kidney stones but it is considered as a possible precursor in their formation [10].…”