Main content area

Chilean crab (Aegla cholchol) as a new source of chitin and chitosan with antifungal properties against Candida spp

Bernabé, Patricia, Becherán, Liliam, Cabrera-Barjas, Gustavo, Nesic, Aleksandra, Alburquenque, Claudio, Tapia, Cecilia V., Taboada, Edelio, Alderete, Joel, De Los Ríos, Patricio
International journal of biological macromolecules 2020 v.149 pp. 962-975
Candida albicans, Candida glabrata, Candida parapsilosis, Candida tropicalis, Fourier transform infrared spectroscopy, alkali treatment, antifungal properties, chemical composition, chemical structure, chitin, chitosan, crabs, exoskeleton, freshwater, minimum inhibitory concentration, molecular weight, nuclear magnetic resonance spectroscopy, scanning electron microscopy, temperature, thermogravimetry, yeasts
In the present work, the chemical composition of the Chilean freshwater crab Aegla cholchol exoskeleton was studied for the first time. α-Chitin was isolated from three main body parts (pincers, legs, carapace), and its content ranged from 9.0–10.4% (w/w). Moreover, chitosan was extracted by alkaline treatment at different temperature and time regimes. Aegla cholchol exoskeleton, chitin and chitosans were characterized by FTIR, TGA, and SEM. Chemical structure of chitin and chitosan was confirmed by NMR spectroscopy. Chitosan molecular weight determinations were carried out by GPC. The obtained chitosan samples had a degree of N-acetylation (DA) between 4 and 15% and molecular weight (Mw) in the range of 65–201 kDa. The antifungal activity of the chitosan samples and the chitooligomer were tested toward twenty isolated clinical strains of Candida yeast. Chitosan with lower DA (4%) and higher molecular weight showed the lowest minimum inhibitory concentration (MIC) values, which was evidenced by the highest antifungal activity toward Candida albicans, Candida tropicalis, Candida glabrata, and Candida parapsilosis. Results suggest that Aegla cholchol is an excellent natural source for production of bioactive materials with potential applications in the health system, to prevent infections associated with Candida strains.