Sustainable textile bio-coatings with PHA from eucalyptus bark enzimatic hydrolysate

 
"Bio-based textile coatings and laminations are gaining interest due to their sustainable properties. Most textile coating and lamination still uses fossil-based polymers. The continued depletion of limited fossil resources and their adverse effects on the environment highlights the need to reduce dependence on them. On the other hand, the valorization of agro-forestry waste and by-products in the value chain, to produce more sustainable materials, has become an urgent research topic. The be@t project developed innovative textile bio-coatings and laminations using polyhydroxyalkanoates (PHAs), an alternative to fossil-based polymers. Polyhydroxyalkanoates (PHAs) are biodegradable, sustainable, and thermally stable biopolymers, making eco-friendly alternatives to fossil-fuel-derived polyesters like polyethylene terephthalate and polyamides. Their diverse applications include medicine, textiles, and packaging. However, their widespread use is hindered by high production costs associated with bacterial cultivation. To address this, low-cost feedstocks like agricultural wastes, organic materials and industrial byproducts are being explored to improve the economic feasibility of PHAs, while aligning with the circular economy concept. In Portugal, ¼ of the forest area is covered by Eucalyptus globulus wood, making its residues abundant and cheap, standing out as a potential carbon and cost-effective source for PHA production. Eucalyptus bark hydrolysate, obtained through enzymatic saccharification using Cellic® CTec3, was used as a sole feedstock for PHA production. Despite their varying performance, several bacteria were able to grow and accumulate PHA with distinct compositions. Pseudomonas citronellolis NRRL B-2504 reached high cell growth (24.4 ± 0.15 g/L), producing a medium-chain-length PHA, but a low biopolymer accumulation was observed under the teste's conditions. Burkholderia thailandensis E264, on the other hand, exhibited lower growth (8.87 ± 0.34 g/L) but reached a higher polyhydroxybutyrate (PHB) content in the cells (12.3wt.%). A newly isolated Pseudomonas sp. strain achieved high PHB accumulation under nitrogen availability (31wt.%). These findings suggest the viability of using eucalyptus bark enzymatic hydrolysate as a sustainable feedstock for PHA production, enabling the development of environmentally responsible textile bio-coatings from underutilized residues. In the be@t project, an innovative generation of textile water-based bio-coatings using polyhydroxyalkanoates (PHAs)-an alternative to fossil-based polymers-was developed. This approach enhances eco-design, aesthetics, and functional properties, allowing the creation of new products with high potential for application in rapidly expanding technical and functional areas. This advancement enables a flexible textile coating with good performance, providing an alternative to leather. Additionally, flexible PHA films were developed and studied for use in textile laminations with natural textile materials such as hemp, linen, organic cotton, and others, to achieve a functional textile solution. These new developments present high potential for application in several areas, including fashion, eco-design, sports, protective apparel, furniture decoration, home textiles, footwear, fashion accessories, among others. Eucalyptus bark hydrolysate, obtained through enzymatic saccharification, was used as feedstock for PHA, promoting the use of underutilized biomass, boosting bio-coating and lamination textiles, and contributing to a circular economy. This study was developed under the Project be@t - Textile Bioeconomy (TC-C12-i01, Sustainable Bioeconomy No. 02/C12-i01/202), promoted by the Recovery and Resilience Plan (RRP), Next Generation EU, for the period 2021 - 2026. "