Lichens are symbiotic associations formed mainly by ascomycete fungi and green algae or cyanobacteria. The presence of chitin in the fungal cell wall has been revealed by previous studies. Considering the presence of fungi in the lichens, this work determines the presence of chitin in a cosmopolitan lichen species Xanthoria parietina. In this study, chitin was derived from a lichen species for the first time and its physicochemical properties were determined by Fourier transform infrared spectroscopy, thermogravimetric analysis, X-ray diffraction, scanning electron microscopy and elemental analysis. The dry weight chitin content of X. parietina was 4.23%, and this chitin was in the α-form. The crystalline index value of the lichen chitin was calculated as 70.1%. The chitin from X. parietina had a smooth surface.
Keywords: biopolymer; characterisation; chitin; isolation; lichen.