Fibre Fusion: Circular Manufacturing of Water Repelling Bacterial Cellulose Through a Biological Approach

Bacteria Cellulose has been identified as a promising material for the replacement for a range of textiles. Cellulose produced by bacteria is pure (compared to plant-based cellulose) and offers a range of useful properties, including mechanical strength and biodegradability. Bacterial cellulose, therefore, is also seen as playing a key role in the circular textile economy. A key drawback with BC however is its capacity to absorb water, which alters its mechanical properties and form. Standard chemical and physical post-production processes, which give BC waterproofing capabilities, are often energy intensive, polluting and take away the biodegradability of the material. Our view is that, to be truly sustainable, the manufacture of biological based textiles must make use of a range of biological processes not only in production, but in post-production as well.

Overall aim in this project is to produce hydrophobic BC materials suitable for circular textile manufacture. We take a biological approach to making water repelling BC based textiles by coating them with hydrophobic proteins. Hydrophobic proteins can be produced by engineered microbes, synthesised in fermentation batch processes, and programmed to attach to the BC polymers increasing their robustness. Hydrophobic proteins can also be broken done using enzymes, which would allow for BC based materials to be biodegraded and recycled for new BC manufacture. To this end we will develop a library of candidate hydrophobic proteins and test their application with different manufacturing processes and at different stages of BC textile production. We will test the effectiveness and robustness of the hydrophobic coatings and the potential for enzymatic end of life treatments which preserve the sugar and the hydrophobic proteins for reuse.

The project brings together an interdisciplinary team of bio-scientists, a materials scientist, textiles specialist and two leading UK based industrial partners including Prozomix (an industrial enzyme developer) and Modern Synthesis (a biomaterial innovation company working on bacterial cellulose-based manufacturing).

Bacterial cellulose (BC) has been identified as a promising material for a sustainable textile industry One significant challenge for BC to be widely applied as a new type of textile fabric is its high level of hydrophilicity. Standard chemical and physical post-production processes, which give BC waterproofing capabilities, are often energy intensive, polluting and take away the biodegradability of the material.

The overall aim in this project is to produce hydrophobic BC materials suitable for circular textile manufacture. We proposed a project base on 3 work packages to address 3 aspects of the innovation, including establishing a library of recombinant hydrophobic proteins as functional polymers to increase BC water repellency (WP1); developing in-situ hydrophobic treatment through BC fibre fabrication/spinning process to reduce the requirement of post-production (WP2) and developing end-of-life treatments for reusing the BC wastes (WP3).

The interdisciplinary team will combine industrial biotechnology, biofabrication and material testing to guarantee the success of the project. Initially the molecular biology techniques will be used to produce recombinant hydrophobic proteins which will be selected from bioinformatic analysis based on their structure, hydrophobicity and solubility. Then the performance of protein candidates will be tested through water contact angel on the drip coated BC. We also will develop the hydrophobic treatment of the BC using hydrophobic proteins during the fermentation stage through in-vitro blending and in the wet/electro spinning stage through fusion and coating. We will evaluate the washing durability and make the recommendation for the future process optimisation. We will also develop the targeted end-of-life enzymatic degradation of hydrophobic BC materials and separate glucose and proteins using gel filtration method for recycling the products which will be fed to the new hydrophobic BC production to close the loop.