Green synthesis approach: extraction of chitosan from fungus mycelia

Abstract

Chitosan, copolymer of glucosamine and N-acetyl glucosamine is mainly derived from chitin, which is present in cell walls of crustaceans and some other microorganisms, such as fungi. Chitosan is emerging as an important biopolymer having a broad range of applications in different fields. On a commercial scale, chitosan is mainly obtained from crustacean shells rather than from the fungal sources. The methods used for extraction of chitosan are laden with many disadvantages. Alternative options of producing chitosan from fungal biomass exist, in fact with superior physico-chemical properties. Researchers around the globe are attempting to commercialize chitosan production and extraction from fungal sources. Chitosan extracted from fungal sources has the potential to completely replace crustacean-derived chitosan. In this context, the present review discusses the potential of fungal biomass resulting from various biotechnological industries or grown on negative/low cost agricultural and industrial wastes and their by-products as an inexpensive source of chitosan. Biologically derived fungal chitosan offers promising advantages over the chitosan obtained from crustacean shells with respect to different physico-chemical attributes. The different aspects of fungal chitosan extraction methods and various parameters having an effect on the yield of chitosan are discussed in detail. This review also deals with essential attributes of chitosan for high value-added applications in different fields.

Chitosans from Rhizopus stolonifer (strain CBMAI 1551): Characterization and Dense Film Formation

“…The easily extracted chitosan from R. arrhizus was determinedto be 86 % DD in a study with agro industrial residues [6]. Fungalchitosans have some distinctive features as absence of allergenic shrimp-related proteins and minerals, among others substances, as stated by Dhillon et al [13] and Kaur &Dhillon [18]. In spite of the great interest in increasing the final chitosan yield forthe fungi used as alternative for its obtainment, many researches havefocused on the native or direct extracted chitosan ( [2], [13], [18], [35], [36]) instead of the semi-synthetic form, via deacetylation of chitin.…”

“…Fungalchitosans have some distinctive features as absence of allergenic shrimp-related proteins and minerals, among others substances, as stated by Dhillon et al [13] and Kaur &Dhillon [18]. In spite of the great interest in increasing the final chitosan yield forthe fungi used as alternative for its obtainment, many researches havefocused on the native or direct extracted chitosan ( [2], [13], [18], [35], [36]) instead of the semi-synthetic form, via deacetylation of chitin. In addition to being easilyextracted, what means less costs and time of production, there is a great chance of finding a way to achieve a native chitosan with high deacetylation degree, and with regular medium-low molecular weight fibers and minimal degradation of fibers.…”

“…Deacetylation transforms chitinin a more easily soluble polymer, chitosan, with broad applications. Chitosan is a nontoxic, film-forming, antioxidant, antimicrobial, biocompatible, mucoadhesive polymer, which presents a unique polycationic charge between natural polysaccharides [4], [13], [19], [33].…”

“…Many works have focused on identifying alternatives for the traditional methods of chitosan obtainment to overcome the unstable supply due to climate instabilities, absence of quality control during production, but especially in the search of a standardized means of obtainment and processing [2], [6], [18], [22], [31], [32], [36]. Fungi of different groups are interesting options for this purpose, especially with the hope to achieve a standardized product, more appropriated for pharmaceutical and medical purposes [13], [18].…”

“…Mucorales is represented by rapid growing moulds, often non-producers of mycotoxins, and by showing constitutive chitosan in all their life cycle, which can be more easily extracted [2], [13], [35]. A specimen of this group was specifically isolated for this study and identified.…”