Elemental Analysis and In Vitro Evaluation of Antibacterial and Antifungal Activities of (L.) Weber ex F.H. Wigg from Călimani Mountains, Romania.

This study aims to complete our research on (L.) Weber ex F.H. Wigg () from the Călimani Mountains, Romania, with an elemental analysis and to explore its antibacterial and antifungal potential. Thus, we analyzed twenty-three metals (Ca, Fe, Mg, Mn, Zn, Al, Ag, Ba, Co, Cr, Cu, Li, Ni, Tl, V, Mo, Pd, Pt, Sb, As, Pb, Cd, and Hg) in dried lichen (dUB) by inductively coupled plasma mass spectrometry (ICP-MS). For the second study, we performed dried lichen extraction with five different solvents (ethyl acetate, acetone, ethanol, methanol, and water), obtaining five dry extracts (UBDE). Then, using an adapted disc diffusion method (DDM), we examined their antimicrobial activity against seven bacterial species-four Gram-positive (, , , and ) and three Gram-negative (, , and )-and two fungi species ( and ). Usnic acid (UA) was used as a positive control. The ICP-MS data showed a considerable Ca content (979.766 µg/g), followed by, in decreasing order, Mg, Mn, Al, Fe, and Zn. Other elements had low levels: Ba, Cu, Pb, and Cr (3.782-1.002 µg/g); insignificant amounts (<1 µg/g) of Hg and V were also found in dUB. The trace elements Ag, As, Cd, Co, Li, Tl, Mo, Pd, Pt, and Sb were below detection limits (<0.1 µg/g). The DDM results-expressed as the size (mm) of the inhibition zone diameter (IZs)-proved that the water extract did not have any inhibitory activity on any pathogens (IZs = 0 mm). Gram-positive bacteria displayed the most significant susceptibility to all other UBDE, with showing the highest level (IZs = 20-22 mm). The most susceptible Gram-negative bacterium was (IZs = 16-20 mm); the others were insensitive to all dry extracts (IZs = 0 mm). The inhibitory activity of UBDE and UA on was slightly higher than on .