Production and characterization of fungal chitosan from Rhizopus stolonifera

Abstract

Chitosan is derived from chitin and is commonly extracted from the arthropod’s exoskeleton and the cell wall of filamentous fungi. The production of chitosan from fungi has recently emerged as a more sustainable alternative to using crustacean exoskeletons. Fungal chitosan production offers several benefits, including reduced dependence on seasonal factors, milder extraction conditions, more homogeneous physicochemical properties, and fewer allergic reactions. In the present work, the production of fungal chitosan from Rhizopus stolonifer was investigated. Chitosan was extracted from the biomass obtained at different incubation times using two different alkali treatments. Remarkably, we achieved a maximum chitosan yield of 56.9 mg per gram of dry biomass, higher than those previously reported for this fungus. Characterization analyses by FT-IR, XRD, and TGA showed substantial similarities with commercial chitosan, confirming the presence of chitosan in all samples. These findings demonstrate that R. stolonifer has the potential as an alternative source of chitosan.