Antimicrobial potential of biopolymers against foodborne pathogens: An updated review.

Biopolymers are natural polymers produced by the cells of living organisms such as plants, animals, microbes, etc. As these natural molecules possess antimicrobial activities against pathogens, they can be a suitable candidate for antimicrobials combating drug-resistant microorganisms including food-borne pathogens. Plant-derived biopolymers such as cellulose, starch, pullulans; microbes-derived chitosan, poly-L-lysine; animal-derived collagen, gelatin, spongin, etc. are proven to possess antimicrobial properties. They exert their antimicrobial activity against food-borne pathogens namely Salmonella typhi, Vibrio cholerae, Bacillus cereus, Clostridium perfringens, E. coli, Campylobacter jejuni, Staphylococcus aureus, etc. As antimicrobial resistance becomes a global phenomenon and threatens the effective prevention and treatment of infections caused by pathogens, biopolymers could be a promising candidate/substitute for conventional antimicrobials available in markets. Biopolymers can have detrimental effects on microbial cells such as disruption of the cell walls and cell membranes; damage to the DNA caused by strand breakage, unwinding, or cross-linking resulting in impeded DNA transcription and replication; lowering the amount of energy required for metabolic processes by compromising the proton motive force. Biopolymers also interfere with the quorum sensing mechanism and biofilm formation of microbes and modulate the host immune system by downregulating mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways resulting in the decreased production of pro-inflammatory cytokines. Furthermore, conjugating these biopolymers with other antimicrobial agents could be a promising approach to control multidrug-resistant foodborne pathogens. This review provides an overview of the various sources of biopolymers with special reference to their antimicrobial applications, especially against foodborne pathogens, and highlights their antimicrobial mechanisms.