Arsenic, a common metalloid, is worldwide recognised as important toxic element for human beings and living organisms (1,2). Natural processes as well as anthropogenic activities contribute to its diffusion and occurrence in the environment (1,2). Fungi, as geoactive agents, can play very important geological roles in several processes, including decomposition, biogeochemical cycling, element biotransformations, metal and mineral transformations, bioweathering and soil formation (3,4). Fungi can tolerate and accumulate high concentration of arsenic and for some species, biovolatilization via methylation was reported (5). In this research, relationships between some soil saprotrophic microfungi and arsenic in relation to growth responses and bioaccumulation were investigated. In particular, Absidia spinosa Lendn., Purpureocillium lilacinum (Thom) Luangsa-ard, Houbraken, Hywel-Jones & Samson (formerly Paecilomyces lilacinus), Metarhizium marquandii (Massee) Kepler, S.A. Rehner & Humber (formerly Paecilomyces marquandii) and Cephalotrichum nanum (Ehrenb.) S. Hughes (formerly Doratomyces nanus), previously isolated from areas with high natural As concentrations, were studied in two different cultural media, namely Malt Extract Agar and Czapek-Dox Agar, and three different concentrations (10, 20 and 50 mg/L) of sodium arsenite (NaAsO2) were tested. Metabolic responses and fungal tolerance to As have been investigated by tolerance indices, namely Rt:Rc (%) and T.I. (%), based on growth data, diametric extension and dry weights, respectively. Most of fungi resulted tolerant to all tested As concentrations, and values of tolerance indices varied according to cultural media and As concentrations. pH medium after fungal growth was measured to study pH variation and metabolic responses. As bioaccumulation in all fungi was observed with chemical analyses by hydride generation atomic fluorescence spectrometry. As tolerance and bioaccumulation by fungi and their metabolic responses shed further light in fungal geoactive roles in the environmental fate of As and provide potential applications in bioremediation. 1) R. Singh, S. Singh, P. Parihar, V. P. Singh, S. M. Prasad (2015) Ecotox. Environ. Safe., 112, 247-270 2) A. Sarkar, B. Paul (2016) Chemosphere, 158, 37-49 3) A. Ceci, M. Kierans, S. Hillier, A. M. Persiani, G. M. Gadd (2015) Appl. Environ. Microbiol., 81, 4955-4964 4) A. Ceci, F. Pinzari, F. Russo, A. M. Persiani, G. M. Gadd (2019) Appl. Microb. Biotechnol., 103, 53-68 5) M. Singh, P.K. Srivastava, P.C. Verma, R.N. Kharwar, N. Singh, R.D. Tripathi (2015) J. Appl. Microb., 119, 1278- 1290
Fungi and arsenic: tolerance and bioaccumulation by soil saprotrophic strains / Ceci, Andrea; Spinelli, Veronica; Massimi, Lorenzo; Guadagnino, Samuele; Canepari, Silvia; Persiani, Anna Maria. - (2019). (Intervento presentato al convegno 114° Congresso della Società Botanica Italiana - VI INTERNATIONAL PLANT SCIENCE CONFERENCE (IPSC) tenutosi a Padova).