AN IN VITRO CONTROL STUDY TO TEST THE ABILITY OF BIOREMEDIATION OF 3 FILAMENTOUS FUNGI FOR THEIR POSSIBLE APPLICATION IN PHYTOREMEDIATION PROCESSES VS REMEDIATION OF SOILS CONTAMINATED BY METALS

Introduction Currently in Italy have been identified polluted sites named as SIN (sites of national interest) that need remediation of soils, ground and/or surface waters to avoid environmental damage and public health risks. Our study has tested in vitro the ability of Trichoderma harzianum, Saccharomyces cerevisiae and Wickerhamomyces anomalus to uptake and bioaccumulate Ni, Cd, Cu, As, Zn, Cr, Pb, V, Hg for a possible application in soil bioremediation. Materials and Methods Broth cultures of the above mentioned fungi were exposed to metals at four different doses. Analyses were carried out after an appropriate incubation time of samples by ICP-MS Elan DRC-e Perkin Elmer. The uptake (%) was calculated as average of the values obtained from the three independent replicates. Results and conclusions Our study showed that all fungi are able to absorb all heavy metals at all different exposure doses. T. harzianum S. cerevisiae and W. anomalus showed a better average performance for: Cd (71.8%), As (73.2%), V(77.0%), Pb (63.3%), Hg (67.8%), the first; Cd (71.3%), Ni (74.3%) and Cu (74.1%), the second; V (64.9%) and Hg (56.4%), the third. Only the Cr test has not given satisfactory results for the too acid pH (<2) of culture medium that reduced the viability of the fungi. A possible solution would be to add an adequate buffer to the culture medium and perform the test again. This preliminary in vitro test was useful for the choice of T. harzianum to be used in combination with a plant species to optimize the phytoextraction of metal from the soil. This plant, once harvested, will have alternative destinies (cogeneration of energy, biofuel production, etc). Bioremediation processes offer a good alternative compared to classical methods, which require the use of more expensive and slower physical-chemical techniques, remaining an excellent alternative for green economy.