Bacterial cellulose (BC): Comprehensive analysis and preparation process and application

1. Introduction to bacterial cellulose (BC)

Bacterial Cellulose (BC) is a nanoscale polymer material synthesized by specific bacteria (such as Komagataeibacter xylinus) under specific conditions. Unlike plant-derived cellulose, bacterial cellulose (BC) has ultra-high purity (free of lignin and hemicellulose), high crystallinity, excellent mechanical properties, excellent water absorption and moisturizing properties, and excellent biocompatibility. , is widely used in biomedical, food industry, environmental protection, electronic devices and cosmetics.

2. Preparation of bacterial cellulose (BC)

1. Sperm selection

Common strains:

Komagataeibacter xylinus (common high yield strain)

Acetobacter xylinum

Gluconacetobacter hansenii

Selection criteria:

Fast synthesis rate

Stable output

Uniform product structure

2. Media formula

(1) Standard medium (HS medium):

Glucose: 2%

Peptone: 0.5%

Yeast powder: 0.5%

Sodium dihydrogen phosphate: 0.27%

Citric acid: 0.115%

(2) Alternative carbon source:

Fructose, sucrose, xylose, glycerol

(3) Selection of nitrogen source:

Yeast extract, peptone, soybean powder

(4) Other additives:

Metal ions (Mg⊃2;⁺, Ca⊃2;⁺): regulate bacterial activity

pH buffering agent: Maintain a stable environment

3. Cultivation conditions

Temperature: 28-30℃

pH: 5.0-7.0 (usually maintained at 6.0)

Training method:

Static culture: Form a film-like BC, suitable for the production of large-area films.

Dynamic culture: Form BC in granular or suspended state to increase yield.

Culture time: 5-10 days (depending on the medium and strain)

Oxygenation conditions: Ensure oxygen supply and promote bacterial activity.

4. Cellulose collection and purification

(1) Collect:

Collect BC gels from the surface of the culture medium or from the liquid.

(2) Purification:

Treatment with alkaline solution (such as 1-2% NaOH) at 80-90°C to remove bacteria and impurities.

Acid treatment (diluted HCl): Neutralize the alkali residue.

(3) Cleaning:

Wash multiple times with deionized water until the pH reaches neutral.

(4) Drying:

Natural dryness: Maintain basic form.

Freeze-drying: retains nanostructures and reduces structural damage.

5. Challenges of industrial production

High production cost: The raw materials and energy consumption of culture medium are relatively high.

Limited output: The output is unstable during mass production.

Pollution risk: Suitable for contamination by other microorganisms during the culture process.

3. Core characteristics of bacterial cellulose (BC)

High purity: Free of lignin and hemicellulose, with uniform structure.

High crystallinity: regular structure, crystallinity up to more than 80%.

High mechanical strength: Excellent tensile strength and toughness.

High water absorption: The water absorption can reach 100 times the self-weight.

Biocompatibility: It does not trigger immune rejection and is highly safe.

High stability: Good chemical stability, acid and alkali resistance.

Customizable: The morphology and structure can be regulated by culture conditions.

4. Key applications of bacterial cellulose (BC)

1. Field of Biomedical

Wound dressing: Highly absorbent, antibacterial, and promotes wound healing.

Artificial skin: Suitable for use in patients with burns and ulcers.

Drug carrier: Controls drug delayed release and reduces drug toxicity and side effects.

Tissue Engineering Scaffold: Supports cell growth and tissue regeneration.

2. Food Industry

Thickeners and stabilizers: Improve food texture.

Food packaging materials: environmentally friendly and biodegradable.

Low-calorie ingredients: used in jelly, beverages, candies, etc.

3. Cosmetics field

Moisturizing mask: High moisturizing properties and improve skin condition.

Skin care substrate: Provides good touch and moisture management.

4. Electronic devices

Flexible electronic materials: for wearable devices and sensors.

Battery separator: Improves battery safety and conductivity.

Sensor material: Applied for environmental monitoring.

5. Environmental protection field

Water purification membrane: Filter heavy metals and organic pollutants.

Biodegradable materials: It can replace some plastic products.

6. Textile and Papermaking

High-strength specialty paper: used for high-end printing materials.

Textile additives: Improve fabric strength and wear resistance.

V. Advantages and challenges of bacterial cellulose (BC)

Advantages:

High purity, biodegradable.

Performance can be adjusted by controlling culture conditions.

It has a wide range of applications and high added value.

challenge:

Industrialization costs are high and technical barriers are high.

Batch stability needs to be improved.

The production process needs to be further optimized.

6. Development direction

Reduce production costs: Develop low-cost culture media and optimize processes.

Improve yield and efficiency: Optimize strain metabolic pathways.

Expand application areas: Make breakthroughs in flexible electronics, biosensing and other fields.

Composite material development: Combined with nanomaterials to develop new composite materials.

Sustainable production: Achieve green manufacturing and a circular economy.

7. Summary

Bacterial cellulose (BC) has become a sustainable high-performance biomaterial with its outstanding physical and chemical properties and multi-field application potential. In the future, through technological innovation, cost control and cross-field integration, bacterial cellulose (BC) will play a greater role in the fields of medical health, smart materials and environmental protection.