Efficient P(3HB) extraction from Burkholderia sacchari cells using non-chlorinated solvents

Abstract

A technique for poly-3-hydroxybutyrate (P(3HB)) extraction with safer, non-chlorinated solvents, was developed, aiming to attain high recovery yields and purities. A wide range of solvents was selected from the GlaxoSmithKline guide as sustainable industrial solvents and the solubility of P(3HB) on those solvents calculated using predictive equations from literature. Anisole, * Corresponding author: Tel.: +351 21 8419137; Fax: +351 21 8419062. e-mail address: teresa.cesario@tecnico.ulisboa.pt + Current address: Politecnico di Milano, Dipartimento di Chimica Materiali e Ingegneria Chimica "Giulio Natta". Via Mancinelli, 7 -20131 Milano MI 2 cyclohexanone and phenetole were used as extraction solvents and the relevant process variables (extraction temperature, extraction time and mass of cells/solvent volume ratio) were optimized.Polymer recovery yields of 97% and 93% were obtained with anisole and cyclohexanone, respectively, at 120-130°C using a cell/solvent ratio of 1.5% (w/v). Maximum polymer purities using these experimental conditions were 98% for both solvents. Recovery yields and polymer purity attained with chloroform (reference solvent) were 97 and 98%, respectively. Higher cell/solvent ratios of 6.0 % (w/v) showed slightly lower recovery yields and purities The average molecular weight and the thermal properties of the polymers extracted with the alternative solvents were comparable to those of the polymers obtained by chloroform extraction, showing that the applied conditions did not significantly alter the properties of the extracted P(3HB).

Bioplastic recovery from wastewater: A new protocol for polyhydroxyalkanoates (PHA) extraction from mixed microbial cultures

“…The MW obtained in the present study are within the range of the molecular weights reported in the literature (1.0 × 10 4 Da -4.0 × 10 6 Da). However, 10 5 Da are the lowest molecular weights described for PHA biopolymers (Fiorese et al, 2009;Rosengart et al, 2015). Furthermost of the molecular weight, the PDI is of great importance since it is going to be an indicator of the homogeneity of a copolymer.…”

Production and recovery of poly‐3‐hydroxybutyrate [P(3HB)] of ultra‐high molecular weight using fed‐batch cultures of Azotobacter vinelandii OPNA strain

“…Several methods have been reported for the extraction of P(3HB) from the biomass of different organisms, and although these procedures are known to offer promising results, there are still obstacles for the efficient recovery of the biopolymer. Several studies in the literature have reported the use of nonhalogenated solvents . Most of these reports used polar or semi‐polar compounds, to solubilize nonpolar hydrophobic compounds, such as PHAs; therefore, in most of these studies it was necessary to use high temperatures (120–150 °C), as well as high pressures to improve the plastic extraction.…”

“…Several studies in the literature have reported the use of nonhalogenated solvents. 6,[35][36][37] Most of these reports used polar or semi-polar compounds, to solubilize nonpolar hydrophobic compounds, such as PHAs; therefore, in most of these studies it was necessary to use high temperatures (120-150 ∘ C), as well as high pressures to improve the plastic extraction. The above implies a high energy consumption, affecting the costs of polymer separation.…”

Industrial Production of Poly-β-hydroxybutyrate from CO2: Can Cyanobacteria Meet this Challenge?

“…Jung et al [103] manipulated the initial inoculum size and the composition of the medium and obtained an Escherichia coli strain that was able to produce PHB at a very high fraction [103]. After spontaneous cell lysis, PHB granules were released into the medium; • Extraction of PHB using non-chlorinated solvents (e.g., anisole) [104] or non-halogenated solvents (e.g., butyl acetate) [105]; • Extraction of PHB with a solvent-free approach using enzyme digestion in an aqueous medium [106]. Martino et al [106] used biomass of Cupriavidus necator DSM 428 grown on used cooking oil (UCO) for extraction of the PHB granules using sodium dodecyl sulphate (SDS), ethylenediaminetetraacetic acid (EDTA), and the enzyme alcalase in an aqueous medium.…”