Applications of chitosan and chitosan based metallic nanoparticles in agrosciences-A review

The second most abundant biological macromolecule, next to cellulose is Chitosan. It is a versatile naturally occurring hydrophilic polysaccharide, derived as a deacetylated form of chitin. Due to its biocompatibility, biodegradability and antimicrobial activity, it has become a significant area of research towards drug delivery system, plant growth promotion, anti-pathogenic potentiality, seed priming and in plant defense mechanism. Various synthetic strategies have been established in recent years that couples different metals with chitosan nanoparticles. Metals like silver, copper, zinc, iron and nickel are highly compatible to form chitosan metallic nanopartides and are proved to be non-toxic to the agricultural plant system. This review highlights the mode of action of nanochitosan on Gram-positive and Gram-negative bacteria in a distinguished manner as well as its action on fungi. A prime focus has been given on the skeletal framework of the metallic nanochitosan partides. Our study also projects the antimicrobial mechanism of chitosan based on its physiochemical properties, environmental factors and the type of organism on which it acts. Moreover, the mechanism for stimulation of plant immunity by metallic nanochitosan has also been reviewed. Our study relies on the conclusion that chitosan metallic nanoparticles showed enhanced anti-pathogenic and plant growth promoting activity in comparison to bulk chitosan. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Chitosan, the second most abundant biological macromolecule after cellulose, is a versatile naturally occurring hydrophilic polysaccharide with significant research applications in drug delivery systems and plant growth promotion due to its biocompatibility, biodegradability, and antimicrobial activity. Recent synthetic strategies have focused on coupling various metals with chitosan nanoparticles, particularly silver, copper, zinc, iron, and nickel, which have shown compatibility and non-toxicity in agricultural plant systems. The study highlights the antimicrobial mechanism of nanochitosan on bacteria and fungi, as well as its role in stimulating plant immunity.