Preparation method of bacterial cellulose: Research and application with stirring culture as the core

introduction

Bacterial Cellulose ( BC ) is a natural polymer material synthesized by metabolism by specific bacteria (such as Compared with plant cellulose, bacterial cellulose has higher purity, stronger crystallinity and excellent mechanical properties, so it is widely used in the fields of food, medicine, cosmetics and new materials. Among the various preparation methods, Komagataeibacter xylinus ). Agitated Culture , as an important way to achieve large-scale production, has gradually become the focus of research and industrial production.

The basic principle of stirring culture

The stirring culture method is to uniformly distribute bacteria in the liquid culture medium through mechanical stirring or gas stirring, so as to synthesize bacterial cellulose throughout the culture system. Unlike static culture that only forms thin films on the liquid surface, stirred culture can produce spherical, granular or irregular fiber groups , greatly improving the overall yield.

Process conditions of stirring culture method

Culture medium composition

Carbon sources: glucose, fructose, sucrose, glycerol;

Nitrogen source: yeast paste, peptone, inorganic salt;

Additives: ethanol, lactic acid, etc. can promote cellulose synthesis.

Process parameters

Temperature: Generally controlled at 28-30℃；

pH : The initial pH is approximately 5.0–6.5；

Dissolved oxygen: maintain high dissolved oxygen levels by stirring and ventilation;

Stirring speed: It is necessary to ensure oxygen supply, and avoid excessive shearing of bacteria.

Product Features

Mainly microspheres, clumps or fibrous structures；

The yield is higher than that of static culture, but the structural regularity is slightly worse.

Comparison between stirring culture method and static culture method

Comparison projects	Static culture method	Stirring culture method
Product form	Film-like, even and flat	Spherical, granular or irregular fibers
Yield	Lower	Higher, suitable for industrialization
Structural features	Highly regular, suitable for functional membrane materials	Diverse structure, suitable for composite materials
Process complexity	Simple, suitable for laboratory research	More complex, need to control stirring and oxygen supply
Feasibility of industrialization	Difficulty in amplification	Continuous production can be achieved in fermentors

Advantages of stirring culture

Significantly increase production : suitable for large-scale production;

The reaction system is controllable : temperature, pH , and dissolved oxygen can be adjusted accurately;

Wide application scope : The product is suitable for composite materials, adsorbents, pharmaceutical carriers, etc.

Existing challenges and optimization directions

Cell shear damage : high-speed stirring will affect bacterial activity;

Product morphology is unstable : it is difficult to obtain film-like cellulose;

Optimization strategy : By improving reactor design, adding protective agents, optimizing gas-liquid mass transfer and utilizing metabolic engineering strains, the quality and yield of BC can be improved .

in conclusion

The stirred culture method provides a reliable way for the large-scale preparation of With the advancement of bacterial cellulose . fermentation process optimization and the application of genetically engineered strains , the stirring culture method will play a greater role in food packaging, medical implants, energy materials and other fields, and promote the industrialization of bacterial cellulose.