A review on recent advances in chitosan applications

Abstract

Chitosan, derivative of chitin is the second most abundant natural polymer and is widely distributed throughout the nature. The numbers of applications of chitosan and their derivatives have been increasing steadily in the last decade. Chitosan has been shown to be a versatile nontoxic material with multiple responses. To date, there is enough evidence indicating that after chitosan application plants can acquire enhanced tolerance to a wide variety of pathogenic microorganisms. A high antimicrobial activity was observed by chitosan against bacteria, viruses, fungi, nematodes and insects. Chitosan can be a cost-effective way to protect crops from microbial pathogens and inhibit development of resistant pathogens. It can assist in the goal of sustainable agriculture in unfavorable climatic conditions e.g. heat, cold, salinity, drought stresses and improve growth. Today, chitosan is considered as a bio functional polysaccharide with probably the most notable growth and potential for applications in various fields. The progress in chitin chemistry and the need to replace additives and non-natural polymers with functional natural-based polymers have opened many new opportunities for chitosan and its derivatives. Chitosan is environmentally friendly and which attributes to the rapid development in its applications in industry but since chitosan is insoluble in water, the use of chitosan in a basic environment is limited. This review hopes to enlist the latest applications of chitosan in different fields to help provide easily accessible knowledge for aspiring researchers.

ANTIFUNGAL ACTIVITY OF CHITOSAN AGAINST Rhizopus stolonifer

“…Further, from the results of the study it can be suggested that the inhibitory effect of chitosan is dose-dependent and it increases with increasing the concentration of chitosan. These results are similar to the findings of Lin et al (2020), andBibi et al (2021). Further, both methods viz., agar dilution and well diffusion revealed a significant inhibition zone at the concentration of 15 mg/µl and this inhibition zone is greater than the inhibition zone observed at the remaining two concentrations (P ≤ 0.05).…”

“…The interaction of chitosan with different types of fungi depends on the composition of the cell wall, and when the reaction occurs, the polymer interferes with the growth of the fungus. Further, some previous research also suggested that chitosan molecules may diffuse within the hyphae and may interfere with enzymes involved in the growth of fungi (Kong et al, 2010;Zhang et al, 2015;Bibi et al, 2021).…”

“…In recent years, there has been a lot of interest in chitosan applications in food processing, nutrition, chemical engineering, pharmaceutical manufacturing, and environmental protection (Bibi et al, 2021). Chitosan has strong antimicrobial activity, and its antimicrobial activity is dependent on molecular weight, degree of acetyl group elimination, pH, and microorganism type (Chien et al, 2016), it is known that polymer characteristics can influence the functional properties of systems where is added (Goy et al, 2009).…”

“…Therefore, the damage caused by fungi can be controlled by the stimulation of defense enzymes (Chien et al, 2016;Meng et al, 2020). Some authors have found that chitosan affects mycelial growth and causes severe damage to the hyphae, and other morphological structures of fungi (Singh & Sharma 2007;Alfaro-Sifuentes et al, 2019;Bibi et al, 2021). Additionally, it permeabilized and penetrated the plasma membrane of different fungal cells (hyphae, spores, and tube germ cells), suggesting that the polymer interacted with external membrane components, causing structural changes that involved pore formation (Lin et al, 2020).…”

Role of Chitosan in Post Harvest Disease Management

“…Chitin is an organic mucopolysaccharide found in crustaceans, insects, and similar organisms, is widely recognized as comprising 2-acetamido-2deoxy-β-D-glucose units linked via β (1→4) connections. The chitosan is the substance (1, 4linked 2-amino-2-deoxy-β-D-glucan), a derivative of chitin that is formed when chitin's deacetylation reaches approximately 50 per cent [5].…”