Bacterial cellulose/lignin nanoparticles composite films with retarded biodegradability

Area of Science:

• Materials Science
• Biotechnology
• Polymer Science

Background:

• Bacterial cellulose (BC) composites offer environmental benefits due to full biodegradability.
• However, their poor durability, particularly in humid environments, limits practical applications.
• Developing BC composites with controlled biodegradability is crucial for broader usability.

Purpose of the Study:

• To create BC/lignin nanoparticle (LNP) composite films with enhanced durability by retarding biodegradability.
• To investigate the impact of different lignin extraction methods on the properties of BC/LNP composites.
• To understand the mechanism behind the retarded biodegradation in BC/LNP composites.

Main Methods:

• Fabrication of three types of LNPs using technical lignins from poplar (deep eutectic solvent, ethanol organosolv, soda/anthraquinone).
• Incorporation of LNPs into BC during fermentation.
• Assessment of BC fermentation productivity, composite film biodegradability under varying enzyme loadings, and degradation mechanisms.

Main Results:

• LNP incorporation had minimal effect on BC productivity.
• All BC/LNP composite films exhibited significantly retarded biodegradation compared to pure BC.
• BC/Soda LNPs demonstrated superior retarded degradation (~58% degradation) at high enzyme loadings (5 mg g⁻¹ BCE) compared to BC/Organosolv (~85%) and BC/DES (~97%).
• At low enzyme loadings (1 mg g⁻¹ BCE), all composite films showed similar retarded degradation (~60%).

Conclusions:

• BC/LNP composite films offer a viable strategy to improve the durability of biodegradable materials.
• The choice of lignin source and extraction method influences the extent of biodegradation retardation.
• Physical barrier and non-productive binding of LNPs are potential mechanisms for inhibiting biodegradation.