Detailed explanation of nanocellulose fermentation and cultivation process: creating a new path to high-purity bacterial cellulose

Detailed explanation of nanocellulose fermentation and cultivation process: creating a new path to high-purity bacterial cellulose

With the continuous development of green and sustainable materials, Nanocellulose has shown great potential in many fields such as medical use, packaging, food, and electronic materials prepared by microbial fermentation . Among them, Bacterial Cellulose (BC ) has become an important member of the nanocellulose family due to its high purity, uniform structure and three-dimensional network stability. This article will focus on the fermentation and culture process flow and key control parameters of bacterial cellulose , providing technical reference for efficient production.

1. Overview of the principles of fermentation and cultivation

Nanocellulose is prepared by fermentation method. It is fermented in liquid culture medium containing carbon and nitrogen sources through fermentation of the genus Komagataeibacter xylinus in a carbon source and nitrogen source, converting substrates such as glucose into β-1,4- glucan chains, which are extracellularly secreted and self-assembled into a three-dimensional nanofiber network, and finally forming a gel-like bacterial cellulose membrane.

2. Typical cultivation process

High-yield strains (such as
Komagataeibacter xylinus ) were selected for preparation and activation of bacterial strains , and cultured in liquid seed medium for 24-48 hours, with temperature controlled at 28-30°C ，pH of about 5.5-6.0.。

The most common medium configuration
is Hestrin-Schramm ( HS ) medium, and the typical formula is as follows:

Static or dynamic fermentation culture

Static fermentation : at room temperature 28-30°C , stand for 7-10 days, and form a BC film on the liquid surface, with uniform products and high purity;

Dynamic fermentation (stirring fermentation or gas lift reactor) : Suitable for pilot or industrialization, with higher yields, but the products are mostly spherical or agglomerated BC。

Collect and purification processing

After collecting the fermentation membrane, the residual bacteria and proteins were removed by treatment with 0.1~0.5 mol/L NaOH solution at 280°C for hours;

Washed to neutral pH multiple times to obtain pure bacterial cellulose.

Post-processing method (optional)

Freeze-drying : forming a porous membrane;

Sonication : Obtain BC nanodispersion;

Composite treatment : blend with other functional materials to form composite materials.

3. Key process parameter control

4. Crafts Advantages and Challenges

Advantages:

No impurity pollution (no lignin, no hemicellulose);

The nanofiber has a small diameter ( 20–100 nm ) and a high crystallinity;

Good biocompatibility and suitable for high-end uses such as medical materials;

Raw materials can be converted from agricultural waste and are green and environmentally friendly.

challenge:

The fermentation cycle is long, affecting production efficiency;

Static fermentation is difficult to scale up;

High requirements for temperature, pH , dissolved oxygen, etc.

5. Future optimization direction

Strain modification and screening
High yield and highly tolerant strains are obtained through synthetic organisms or directed evolution.

Optimize
the use of cheap carbon sources such as pomace and corn core hydrolysate to reduce costs.

Bioreactor development
and introduction of industrial equipment such as membrane bioreactors and gas-lift fermentation tanks to achieve continuous cultivation.

The composite material design
fermentation process introduces nanoparticles and functional polymer co-culture to directly obtain functional BC membranes.