Development of PHA-based biocomposites with Bacterial Cellulose and CGC for textile and active packaging applications.

Publicações

Sustainable Production of Poly(3-hydroxybutyrate) Using Eucalyptus Bark: Integration with Green Downstream Processing

Publication . Matias, João; Rodrigues, Thomas; Torres, Cristiana A. V.; Marques, Susana; Ribeiro, Belina; Gírio, Francisco; Reis, Maria A.; Freitas, Filomena

ABSTRACT: This study integrates the valorization of a lignocellulose material into poly(3-hydroxybutyrate), P(3HB), with biopolymer extraction from bacterial cells with the enzyme alcalase. The work focused on Burkholderia thailandensis DSM 13276 as the P(3HB) producer and on eucalyptus bark, a byproduct from the pulp industry, as the sole feedstock for bacterial cultivation. The eucalyptus bark was hydrolyzed by a cellulolytic enzymatic cocktail following steam explosion and further subjected to ultrafiltration for enzyme recovery. The resulting hydrolysate supported good cell growth, achieving a cell dry weight of 7.67 +/- 0.16 g/L within 72 h of cultivation, and high P(3HB) content (60.0 +/- 2.19 wt %) in the bacterial cells, clearly favoring biopolymer synthesis over cell growth, as demonstrated by the polymer and growth yields (0.190 gP(3HB)/gsugar and 0.026 gX/gsugar, respectively). High extraction efficiency (96%) and biopolymer purity (100 +/- 3.38%) were reached by enzymatic treatment, resulting in a sample with properties aligned with those of commercial P(3HB) in terms of molecular mass distribution, crystallinity, and thermal properties. These findings demonstrate the successful use of a sustainable feedstock together with the application of environmentally friendly technologies based on the use of enzymes for both lignocellulosic saccharification and biopolymer recovery to develop high-quality bioplastics, advancing the goals of a circular bioeconomy.

2026-02Artigo científico

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Upcycling post-consumer household textiles into a biodegradable thermoplastic

Publication . Rodrigues, Thomas; Matias, João; Moura, Patrícia; Abreu, Mariana; Gírio, Francisco; Braga, Adelaide; Dias, J. C.; Rovisco, Ana; Fortunato, Elvira; Torres, Cristiana A. V.; Reis, Maria A.; Marques, Susana; Freitas, Filomena; Silva, Carla J.

ABSTRACT: This study demonstrates the biological valorization of post-consumer cotton-based towels, a significant household textile waste stream, into poly(3-hydroxybutyrate) P(3HB), a biodegradable and biocompatible thermoplastic. The textile waste was mechanically defibrillated, and pre-treated by freezing in NaOH/urea, rendering the cellulose fibers more accessible to saccharification, which was achieved by hydrolysis with Cellic (R) CTec3 cellulase. The resulting hydrolysate, with a glucose concentration of 102.3 g/L, was used to supply glucose as the carbon source for the batch bioreactor cultivation of the bacterium Burkholderia thailandensis E264. With an initial glucose concentration of 40 g/L, a maximum P(3HB) production of 9.17 +/- 1.01 g/L was observed after 53 h of cultivation, corresponding to an overall volumetric productivity of 0.165 g/(L h) and a product yield of 0.218 g/g. The P(3HB) exhibited an average molecular weight of 497 kDa and a polydispersity index of 2.6, with melting and thermal degradation temperatures of 170 and 291 degrees C, respectively, crystallinity index of 78.8%. Importantly, its tensile properties (Young's Modulus of 563 +/- 62 MPa and tensile strength of 27 +/- 2 MPa) were comparable to P(3HB) produced by other bacteria, including commercial products. The findings of this study demonstrate the feasibility of upcycling cotton-based household waste into a value-added sustainable and biodegradable material with properties matching those of commercial thermoplastics.

2026-09Artigo científico

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Palavras-chave

, Engineering and technology ,Engineering and technology/Materials engineering

Entidade financiadora

Fundação para a Ciência e a Tecnologia, I.P.

Número da atribuição

2023.03035.BD