In the context of the rapid development of bio-based materials, bacterial cellulose ( Bacterial Cellulose ，BC ), as a natural polymer material synthesized by microbial fermentation, is moving from laboratory research to large-scale application. Compared with plant cellulose, bacterial cellulose has significant advantages in purity, microstructure and performance stability, and is an important research direction in the current field of functional materials.

1. Formation mechanism and structural nature of bacterial cellulose

Bacterial cellulose is mainly secreted and synthesized by cellulose-producing bacteria such as Komagataeibacter xylinus under aerobic conditions. Its molecular structure is the same as that of plant cellulose, which is a linear polysaccharide connected by β-1,4- glucosidic bonds, but its formation process is different: bacteria directly polymerize and extrude glucose during the fermentation process to form nanoscale fibers, which are then self-assembled to form a three-dimensional network structure.

This ' in-situ nanobuilding ' mechanism enables BC to have the following structural characteristics:

Fiber diameter 20–100 nm

High crystallinity (usually up to 80% or more)

High specific surface area

Three-dimensional interpenetrating hydrogen bonding network

Since it does not contain lignin and hemicellulose, the purity of BC is close to 100% , avoiding the complex chemical extraction process of plant cellulose, and the material consistency is higher.

2. Analysis of core performance advantages

1. High mechanical strength and structural stability

The tensile strength of BC dry film can reach more than 200 MPa , and the elastic modulus is excellent. Its three-dimensional nanonetwork structure remains intact in the wet state, making it both flexible and strong, making it outstanding in soft material systems.

2. Excellent water retention and breathability properties

The moisture content of BC can exceed 90% , forming a stable hydrogel structure with good internal pore connectivity. This structure can maintain a humid environment while achieving gas exchange, and is especially suitable for wound dressings and tissue engineering scaffolds.

3. Excellent biocompatibility

Due to its natural origin and pure structure, BC has a low risk of inflammatory reactions in cell culture, skin contact materials and implant-grade materials, making it an ideal biomedical substrate.

3. Preparation process and controllable adjustment

Bacterial cellulose is usually produced by static fermentation or dynamic fermentation. By regulating:

Carbon source type and concentration

Fermentation temperature (generally 28-30℃ )

pH range ( 4.5–6.0 )

Dissolved oxygen level

Can affect fiber arrangement and film thickness structure.

The post-processing stage includes alkali washing and purification, filter press dehydration, drying and shaping, and functional modification. In recent years, technologies such as surface TEMPO oxidation, carboxylation, and conductive nanomaterial composites have continued to mature, upgrading BC from structural materials to functional materials.

4. Key application areas

(1) Medical and regenerative medicine

BC has been widely used in wound dressings, artificial skin and soft tissue repair materials. Its high water retention and breathability can provide a stable healing environment for wounds while avoiding secondary damage.

(2) Flexible electronics and functional composite materials

With the development of wearable devices, the demand for flexible substrate materials increases. BC can be used as a conductive polymer or graphene composite matrix to achieve:

Flexible sensor substrate

Flexible conductive film

Degradable electronic materials

Its mechanical strength and dimensional stability provide support for functional integration.

(3) Green packaging and sustainable materials

Driven by environmental protection policies, BC , as a degradable biofilm material, can be used in food packaging, functional coatings and high-barrier material systems, with both sustainability and high performance.

5. Industrialization Trends and Future Directions

The core factors currently limiting the large-scale application of BC still include fermentation cost and yield issues. Future development directions mainly focus on:

High-yield strain screening and metabolic engineering optimization

Continuous fermentation process

Functional customization modification

High value-added development of composite materials

With the advancement of synthetic biology and fermentation engineering technology, bacterial cellulose is expected to form a large-scale market in the fields of high-end medical materials, smart wearable devices, and sustainable packaging.

Conclusion

Bacterial cellulose has become an important component of bio-based functional materials due to its unique nano-network structure, high purity and excellent comprehensive properties. In the future, as the technology matures and costs are optimized, its industrialization potential will be further released, providing continuous innovation power for the fields of green materials and high-end manufacturing.