The increasing need for biodegradable polymers demands efficient and environmentally friendly extraction methods. In this study, a simple and sustainable method for extracting polyhydroxybutyrate (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHB-co-HV) from and a mixed methanotrophic consortium with different biopolymer contents was presented. The extraction of biopolymers with 1,3-dioxolane was initially investigated by varying the biomass-to-solvent ratio (i.
View Article and Find Full Text PDFPoly(3-hydroxybutyrate-co-3-hydroxyvalerate) is a biobased and biodegradable polymer that could efficiently replace fossil-based plastics. However, its widespread deployment is slowed down by the high production cost. In this work, the techno-economic assessment of the process for producing poly(3-hydroxybutyrate-co-3-hydroxyvalerate) from low-cost substrates, such as methane and valeric acid derived from the anaerobic digestion of organic wastes, is proposed.
View Article and Find Full Text PDFDue to their excellent properties, polyhydroxyalkanoates are gaining increasing recognition in the biodegradable polymer market. These biogenic polyesters are characterized by high biodegradability in multiple environments, overcoming the limitation of composting plants only and their versatility in production. The most consolidated techniques in the literature or the reference legislation for the physical, chemical and mechanical characterisation of the final product are reported since its usability on the market is still linked to its quality, including the biodegradability certificate.
View Article and Find Full Text PDFPolyhydroxyalkanoates (PHAs) are biobased and biodegradable polymers that could effectively replace fossil-based and non-biodegradable plastics. However, their production is currently limited by the high production costs, mainly due to the costly carbon sources used, low productivity and quality of the materials produced. A potential solution lies in utilizing cheap and renewable carbon sources as the primary feedstock during the biological production of PHAs, paving the way for a completely sustainable and economically viable process.
View Article and Find Full Text PDFIn this work, the potential of a synthetic coculture and a mixed methanotrophic consortium to synthesize poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHBV) from renewable and waste-based feedstocks was assessed batchwise. cocultivated with and a -enriched culture previously grown on methane were subjected to nutrient starvation in a medium enriched with valeric acid (30% w w of ) or with a VFAs mixture containing acetic, propionic, butyric, and valeric acids (15% w w of ) under a CH:O or air atmosphere. For all test series, pH was adjusted to 7 after adding the cosubstrates, and a negligible substrate consumption or polymer production was considered the end point of the trial.
View Article and Find Full Text PDFIn this work, the potential of Methylocystis hirsuta to simultaneously use methane and volatile fatty acids mixtures for triggering PHBV accumulation was assessed for the first time batchwise. Biotic controls carried out with CH alone confirmed the inability of Methylocystis hirsuta to produce PHBV and achieved 71.2 ± 7 g md of PHB.
View Article and Find Full Text PDFBacterially produced polyhydroxyalkanoates are valuable substitutes for petrochemical plastics, but their current production capacities are very scarce. Producing poly(3-hydroxybutyrate--3-hydroxyvalerate) (PHB--HV) from methane and odd-chain carbon fatty acids could make the production of this biodegradable polymer cost-effective. This study analyzes the main factors affecting methanotrophic growth and poly(3-hydroxybutyrate--3-hydroxyvalerate) accumulation, simulating a pilot-scale process based on a double-stage approach.
View Article and Find Full Text PDFThe pressing problem posed by plastic pollution has led to other, environmentally friendly alternatives, such as polyhydroxyalkanoates. This work proposes an innovative process to produce poly(3-hydroxybutyrate) by replacing expensive substrates, such as sugars, with methane. A two-step process was simulated: a first fermentation is performed in a continuous mode for 20 days to grow a strain belonging to the genus Methylocystis, while a second semi-continuous and nitrogen-limited fermentation is employed to induce the poly(3-hydroxybutyrate) accumulation within 12 days.
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