Biologically derived antimicrobial materials toward sustainable development

Abstract

The polymers that have the capacity to kill the pathogens such as bacteria, fungi, or viruses are known to possess antimicrobial properties. These polymers can be naturally available having the inbuilt antimicrobial capacity such as chitosan, poly-L-lysine, polyguanidine or can be physically or chemically altered to inculcate antimicrobial properties. The presence of cations such as quaternary phosphorium, ammonium, or guanidium in polymers resulted in biocidal properties. The property of cationic exchange in polymers enables the strong binding with microbial cell wall. Other feature is their hydrophobicity, which helps in their binding to lipid bilayer and easy insertion into microbial cell wall. The three major fields in which biopolymers have shown wide applications are water treatment, food preservation, and biomedical appliances. The source of biopolymers can be biomass-based such as whey proteins, casein, gluten, cellulose, pectin, alginate, starch, carrageenan, or microbe-based, that is, polyhydroxy alkanoates, polyhydroxy butyrate, or biotechnology-based poly lactic acid. In environment field, due to property of insolubility in water, these biopolymers can be added to disinfect public water supplies and waste water treatment plants in industries. These biopolymers can kill or deactivate infectious microbes without releasing any toxic chemicals. In medical field, there is a great risk of infection when catheters or various medical plastic equipment came in contact with the blood vessels and pathogens enter into blood stream. There is the possibility that microbes attach and grow on the surface of plastic polymers and form biofilm. With passage of time, this biofilm can detach from surface of surgical equipment and mixes and infects the blood. Biopolymers can be successfully coated in implants in dental materials, wound dressings, cosmetic products, and catheter tubes to disinfect the material. In food preservation, biopolymers coating resulted in increasing the shelf life or long-term storage by extending the lag phase of pathogens. Chitosan coating is widely used to protect vegetable and fruits from fungal contamination. This chapter will deal with the applications of biopolymers against a variety of pathogens either natural or modified in the area of environment, food, and medical field. © 2025 Elsevier Ltd. All rights reserved.