Banana pseudo-stem and cattle manure for lactic acid production and the application of polylactic acid-cellulose silver nanoparticle-based nanocomposite films in food storage

Lactic acid is used in various industrial processes, including the production of emulsifiers, polymers, cosmetics, and pharmaceuticals. Fermentation of renewable biomass from natural sources has several advantages over costly chemical methods. Thermal and acidic pretreatments were used to improve the availability of sugars in the medium. Bacillus coagulans was isolated from the banana pseudostem; it was cultured with cattle manure-banana pseudostem for the improved production of lactic acid. Lactic acid production was high in the culture medium containing a 1:1 ratio of cow manure and banana pseudostem after 72 h of fermentation. After 24 h, lactic acid production was 19.4 ± 1.2 g/kg substrate, and it increased after 48 h (20.5 ± 0.1 g/kg substrate), and 72 h (26.3 ± 0.1 g/kg substrate). Lactic acid synthesized by B. coagulans was purified and used for the synthesis of polylactic acid. Polylactic acid was used for the fabrication of composite materials with cellulose and silver nanoparticles. The scanning electron microscopy image showed a smooth surface with uniform particle sizes. The fabricated nanoparticles showed antibacterial activity against food spoilage bacteria. The film was used to pack goat meat and chicken meat. The fabricated film reduced the bacterial load in the stored meat and improved food quality.