Consideration of lichen organisms as the ecofriendly source of metal nanoparticles (MNPs) and metal oxide NPs (MONPs) synthesis is seldom. In this study, Ag and Cu MNPs as well as TiO 2 , ZnO, and Fe 3 O 4 MONPs were green synthesized by Protoparmeliopsis muralis lichen aqueous extract. First, physicochemical characterization by UV−vis spectroscopy, XRD, FT-IR, FESEM, and TEM techniques demonstrated the presence possibility of secondary metabolites around formed MNPs/MONPs with different diameters and shapes (spherical, triangular, polyhedral, and cubic). The antibacterial, antibiofilm, antiquorum sensing, and antioxidant abilities of these MNPs/MONPs against multi drug resistant (MDR) bacterium (Staphylococcus aureus ATCC 43300) and reference bacteria (Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853) were then evaluated by in vitro tests. Results of disc diffusion and MIC/MBC assays of Ag NPs as an effective antibacterial agent illustrated a higher sensitivity of the P. aeruginosa pathogen than E. coli and S. aureus. In next steps, a significant reduction was observed in the biofilm formation of each bacterium and pyocyanin synthesis by P. aeruginosa under Ag NPs. This investigation presents novel clean production of five MNPs/MONPs with prominent advantages of being ecofriendly and cost-effective and having antipathogen properties.

In this paper, 80 lichen taxa and 9 lichenicolous fungi are reported as new to Iran. These include a tropical element represented by Lithothelium obtectum and Melanotopelia africana, and a North American element with Lecanora flowersiana, L. juniperina, L. percrenata, and L. wetmorei.

The new species Megaspora rimisorediata Valadbeigi & A. Nordin is described from Iran, where it mainly grows on tree bark but also on calciferous rocks and mosses. It is characterized by a pale ochraceous to bluish grey, cracked and sorediate thallus, very rarely producing ascomata. It appears to be rather commonly distributed in Iran. Its close affinity with Megaspora verrucosa is illustrated in a graph resulting from a phylogenetic network analysis of nuclear rDNA ITS1-5.8S-ITS2 sequences from specimens representing the different genera of Megasporaceae.

The species of the genus Immersaria in Iran are reviewed. Immersaria iranica is described as a new species in the Lecideaceae, characterized by pycnoconidia opening by stellate, winding cracks and 2#-O-methylsuperphyllinic acid as major secondary metabolite. The characters separating it from other taxa of the Lecideaceae are discussed. Immersaria athroocarpa and I. cupreoatra are new records for Iran. An identification key and a table with diagnostic characters of the species hitherto known from Iran are provided.

Background: Despite the wide diversity of the basic growth forms (crustose, squamulose, foliose, and fruticose), all lichens have a similar internal morphology. The bulk of the lichen's body is formed from filaments of the fungal partner, and the relative density of these filaments defines the layers within the lichen. Objectives: To continue and complete the previous study, this study was designed to assess the antibacterial and antifungal activity of different extractions of lichens. Materials and Methods: Acetone, methanol and aqueous extractions of the lichens, including Acarospora strigata, Collema crispum, Placidium squamulosum, Physcia biziana, Lecanora prophetae-eliae and Ramalina farinacea, were evaluated in vitro against seven bacterial strains (Escherichia coli ATCC1652, Salmonella typhi ATCC1679, Proteus mirabilis ATCC2601, Staphylococcus aureus ATCC1885, Enterococcus faecalis ATCC2321, Staphylococcus epidermidis ATCC2405, and Bacillus cereus ATCC13061), and two fungi (Verticillium dahlia, Fusarium moniliforme). The antibacterial activity was estimated via disc diffusion method and the minimal inhibitory concentration (MIC) was determined via broth tube dilution method. Results: Among the six tested lichens, methanol extracts of P. squamulosum, P. biziana, and L. prophetae-eliae showed relatively high antibacterial activities and also the acetone extraction of L. prophetae-eliae showed antibacterial activity against S. epidermidis and B. cereus. The bacteria were more sensitive than the fungi. The methanol extract of P. squamulosum showed the highest antibacterial activity; besides, the least amount of MIC value was 250 mg/mL. Conclusions: It seems that the tested lichens could be effective as antibiotics; especially, in terms of drug resistance, they can be proper substitutes; but, further studies are suggested.