Microbial Levan as a Biopolymer for Active Antimicrobial Food Packaging Films: Characterization, Antimicrobial...

Levan is a naturally occurring fructose-based homopolysaccharide produced by diverse microbial and plant sources, with microbial levan offering greater economic feasibility and industrial relevance. It is synthesized predominantly by bacteria such as Zymomonas mobilis, Erwinia herbicola, and Bacillus subtilis and has also been reported in select fungi and yeasts; however, yeast-based levan production remains comparatively limited in terms of strain diversity, productivity, and industrial-scale implementation. Growing interest in antimicrobial packaging, driven by its ability to enhance safety and extend the shelf life of perishable foods, has positioned levan as a promising bio-based material. Its distinctive structural features and antibacterial mechanisms enable effective inhibition of spoilage and pathogenic microorganisms. This review explores microbial levan extraction, purification, and characterization, along with its integration into films, coatings, and nanocomposites for active antimicrobial packaging applications. By highlighting levan's functional contributions, comparative advantages, and application-specific performance, this work demonstrates its potential as a sustainable biopolymer for food packaging.