{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T08:03:24Z","timestamp":1777622604410,"version":"3.51.4"},"reference-count":35,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2022,5,25]],"date-time":"2022-05-25T00:00:00Z","timestamp":1653436800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"INGREEN","award":["838120"],"award-info":[{"award-number":["838120"]}]},{"name":"INGREEN","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}]},{"name":"Bio-based Industries Joint Undertaking (JU)","award":["838120"],"award-info":[{"award-number":["838120"]}]},{"name":"Bio-based Industries Joint Undertaking (JU)","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}]},{"name":"European Union\u2019s Horizon 2020","award":["838120"],"award-info":[{"award-number":["838120"]}]},{"name":"European Union\u2019s Horizon 2020","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}]},{"name":"Bio-based Industries Consortium","award":["838120"],"award-info":[{"award-number":["838120"]}]},{"name":"Bio-based Industries Consortium","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}]},{"name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["838120"],"award-info":[{"award-number":["838120"]}]},{"name":"FCT\u2014Funda\u00e7\u00e3o para a Ci\u00eancia e a Tecnologia","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["838120"],"award-info":[{"award-number":["838120"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["2020.08574.BD"],"award-info":[{"award-number":["2020.08574.BD"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>Polyhydroxyalkanoates (PHA) are biopolymers with potential to replace conventional oil-based plastics. However, PHA high production costs limit their scope of commercial applications. Downstream processing is currently the major cost factor for PHA production but one of the least investigated aspects of the PHA production chain. In this study, the extraction of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) produced at pilot scale by a mixed microbial culture was performed using sodium hydroxide (NaOH) or sodium hypochlorite (NaClO) as digestion agents of non-PHA cellular mass. Optimal conditions for digestion with NaOH (0.3 M, 4.8 h) and NaClO (9.0%, 3.4 h) resulted in polymers with a PHA purity and recovery of ca. 100%, in the case of the former and ca. 99% and 90%, respectively, in the case of the latter. These methods presented higher PHA recoveries than extraction by soxhlet with chloroform, the benchmark protocol for PHA extraction. The polymers extracted by the three methods presented similar PHA purities, molecular weights and polydispersity indices. Using the optimized conditions for NaOH and NaClO digestions, this study analyzed the effect of the initial intracellular PHA content (40\u201370%), biomass concentration (20\u2013100 g\/L) and biomass pre-treatment (fresh vs. dried vs. lyophilized) on the performance of PHA extraction by these two methods.<\/jats:p>","DOI":"10.3390\/polym14112155","type":"journal-article","created":{"date-parts":[[2022,5,31]],"date-time":"2022-05-31T00:25:12Z","timestamp":1653956712000},"page":"2155","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":41,"title":["Polyhydroxyalkanoates from a Mixed Microbial Culture: Extraction Optimization and Polymer Characterization"],"prefix":"10.3390","volume":"14","author":[{"given":"Ana Marta","family":"Rodrigues","sequence":"first","affiliation":[{"name":"Associate Laboratory i4HB\u2013Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"UCIBIO\u2014Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]},{"given":"Rita Dias Guard\u00e3o","family":"Franca","sequence":"additional","affiliation":[{"name":"Associate Laboratory i4HB\u2013Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"UCIBIO\u2014Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1487-0889","authenticated-orcid":false,"given":"Madalena","family":"Dion\u00edsio","sequence":"additional","affiliation":[{"name":"LAQV-REQUIMTE, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]},{"given":"Chantal","family":"Sevrin","sequence":"additional","affiliation":[{"name":"CEIB-Interfaculty Research Centre of Biomaterials, University of Liege, B-4000 Li\u00e8ge, Belgium"}]},{"given":"Christian","family":"Grandfils","sequence":"additional","affiliation":[{"name":"CEIB-Interfaculty Research Centre of Biomaterials, University of Liege, B-4000 Li\u00e8ge, Belgium"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4000-1836","authenticated-orcid":false,"given":"Maria A. M.","family":"Reis","sequence":"additional","affiliation":[{"name":"Associate Laboratory i4HB\u2013Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"UCIBIO\u2014Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5506-4421","authenticated-orcid":false,"given":"N\u00eddia Dana","family":"Louren\u00e7o","sequence":"additional","affiliation":[{"name":"Associate Laboratory i4HB\u2013Institute for Health and Bioeconomy, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"},{"name":"UCIBIO\u2014Applied Molecular Biosciences Unit, Department of Chemistry, NOVA School of Science and Technology, NOVA University Lisbon, 2829-516 Caparica, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2022,5,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"624021","DOI":"10.3389\/fbioe.2021.624021","article-title":"Recovery of Polyhydroxyalkanoates From Single and Mixed Microbial Cultures: A Review","volume":"9","author":"Pagliano","year":"2021","journal-title":"Front. Bioeng. Biotechnol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"122478","DOI":"10.1016\/j.biortech.2019.122478","article-title":"Recovery of Polyhydroxyalkanoates (PHAs) from Wastewater: A Review","volume":"297","author":"Mannina","year":"2020","journal-title":"Bioresour. Technol."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1186\/s13568-015-0096-5","article-title":"Feasibility Study of an Alkaline-Based Chemical Treatment for the Purification of Polyhydroxybutyrate Produced by a Mixed Enriched Culture","volume":"5","author":"Jiang","year":"2015","journal-title":"AMB Express"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"113","DOI":"10.2478\/ebtj-2020-0013","article-title":"Established and Advanced Approaches for Recovery of Microbial Polyhydroxyalkanoate (PHA) Biopolyesters from Surrounding Microbial Biomass","volume":"4","author":"Koller","year":"2020","journal-title":"EuroBiotech J."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"549","DOI":"10.1002\/elsc.201300021","article-title":"Strategies for Recovery and Purification of Poly[(R)-3-Hydroxyalkanoates] (PHA) Biopolyesters from Surrounding Biomass","volume":"13","author":"Koller","year":"2013","journal-title":"Eng. Life Sci."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"546","DOI":"10.1002\/(SICI)1097-0290(19990305)62:5<546::AID-BIT6>3.0.CO;2-0","article-title":"Efficient and Economical Recovery of Poly(3-Hydroxybutyrate) from Recombinant Escherichia Coli by Simple Digestion with Chemicals","volume":"62","author":"Choi","year":"1999","journal-title":"Biotechnol. Bioeng."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1007\/s12010-012-9677-9","article-title":"Enhanced Recovery and Purification of P(3HB-Co-3HHx) from Recombinant Cupriavidus Necator Using Alkaline Digestion Method","volume":"167","author":"Anis","year":"2012","journal-title":"Appl. Biochem. Biotechnol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"783","DOI":"10.1089\/ees.2011.0255","article-title":"Efficient Polyhydroxyalkanoate Recovery from Recombinant Cupriavidus Necator by Using Low Concentration of NaOH","volume":"29","author":"Mohammadi","year":"2012","journal-title":"Environ. Eng. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1186\/2191-0855-2-59","article-title":"Large Scale Extraction of Poly(3-Hydroxybutyrate) from Ralstonia Eutropha H16 Using Sodium Hypochlorite","volume":"2","author":"Heinrich","year":"2012","journal-title":"AMB Express"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"107283","DOI":"10.1016\/j.bej.2019.107283","article-title":"A Sustainable Approach for the Downstream Processing of Bacterial Polyhydroxyalkanoates: State-of-the-Art and Latest Developments","volume":"150","author":"Roy","year":"2019","journal-title":"Biochem. Eng. J."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1016\/j.nbt.2013.08.001","article-title":"Polyhydroxyalkanoates Production with Mixed Microbial Cultures: From Culture Selection to Polymer Recovery in a High-Rate Continuous Process","volume":"31","author":"Villano","year":"2014","journal-title":"New Biotechnol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"250","DOI":"10.1016\/j.bej.2014.10.018","article-title":"Comparison of Several Methods for the Separation of Poly(3-Hydroxybutyrate) from Cupriavidus Necator H16 Cultures","volume":"93","author":"Lema","year":"2015","journal-title":"Biochem. Eng. J."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"523","DOI":"10.1023\/A:1025174731814","article-title":"Optimization of Fermentation Conditions for the Production of Ethanol from Sago Starch Using Response Surface Methodology","volume":"19","author":"Ratnam","year":"2003","journal-title":"World J. Microbiol. Biotechnol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1738","DOI":"10.1016\/j.matpr.2021.12.377","article-title":"Application of Response Surface Methodology with Central Composite Design to Evaluate the Extraction of U(VI) into Ionic Liquids","volume":"57","author":"Kumar","year":"2022","journal-title":"Mater. Today Proc."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1144","DOI":"10.1016\/j.ijbiomac.2018.09.064","article-title":"Demonstration of the Adhesive Properties of the Medium-Chain-Length Polyhydroxyalkanoate Produced by Pseudomonas Chlororaphis Subsp. Aurantiaca from Glycerol","volume":"122","author":"Pereira","year":"2019","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"243","DOI":"10.1016\/j.ijbiomac.2015.10.043","article-title":"Characterization of Medium Chain Length Polyhydroxyalkanoate Produced from Olive Oil Deodorizer Distillate","volume":"82","author":"Cruz","year":"2016","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"534","DOI":"10.1080\/01496395.2011.615788","article-title":"Separation and Purification of Polyhydroxyalkanoates from Newly Isolated Comamonas Sp. EB172 by Simple Digestion with Sodium Hydroxide","volume":"47","author":"Mohammadi","year":"2012","journal-title":"Sep. Sci. Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"34","DOI":"10.1128\/aem.61.1.34-39.1995","article-title":"Recovery and Characterization of Poly(3-Hydroxybutyric Acid) Synthesized in Alcaligenes Eutrophus and Recombinant Escherichia Coli","volume":"61","author":"Chang","year":"1995","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"227","DOI":"10.1007\/BF01876053","article-title":"PHB Recovery by Hypochlorite Digestion of Non-PHB Biomass","volume":"3","author":"Berger","year":"1989","journal-title":"Biotechnol. Tech."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2762","DOI":"10.1128\/AEM.65.6.2762-2764.1999","article-title":"Removal of Endotoxin during Purification of Poly(3-Hydroxybutyrate) from Gram-Negative Bacteria","volume":"65","author":"Choi","year":"1999","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_21","first-page":"924","article-title":"A Rapid Hypochlorite Method for Extraction of Polyhydroxyalkanoates from Bacterial Cells","volume":"40","author":"Rawte","year":"2002","journal-title":"Indian J. Exp. Biol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"3","DOI":"10.1016\/S0169-7439(98)00065-3","article-title":"Experimental Design and Optimization","volume":"42","author":"Lundstedt","year":"1998","journal-title":"Chemom. Intell. Lab. Syst."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"148","DOI":"10.1016\/j.biortech.2012.05.106","article-title":"Study of the Interactive Effect of Temperature and PH on Exopolysaccharide Production by Enterobacter A47 Using Multivariate Statistical Analysis","volume":"119","author":"Torres","year":"2012","journal-title":"Bioresour. Technol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"937","DOI":"10.1007\/s10529-010-0513-4","article-title":"Improved Detergent-Based Recovery of Polyhydroxyalkanoates (PHAs)","volume":"33","author":"Yang","year":"2011","journal-title":"Biotechnol. Lett."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"839","DOI":"10.1073\/pnas.89.3.839","article-title":"Materials Derived from Biomass\/Biodegradable Materials","volume":"89","author":"Luzier","year":"1992","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1007\/s002530051357","article-title":"Factors Affecting the Economics of Polyhydroxyalkanoate Production by Bacterial Fermentation","volume":"51","author":"Choi","year":"1999","journal-title":"Appl. Microb. Biotechnol."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1016\/S0032-9592(98)00082-X","article-title":"Recovery of Poly-3-Hydroxybutyrate from Alcaligenes Eutrophus by Surfactant-Chelate Aqueous System","volume":"34","author":"Chen","year":"1999","journal-title":"Process Biochem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"124100","DOI":"10.1016\/j.polymer.2021.124100","article-title":"Poly(L-Lactic Acid)\/Lithium Ferrite Composites: Electrical Properties","volume":"230","author":"Teixeira","year":"2021","journal-title":"Polymer"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2630","DOI":"10.1002\/polb.21599","article-title":"Cold Crystallization and Postmelting Crystallization of PLA Plasticized by Compressed Carbon Dioxide","volume":"46","author":"Yu","year":"2008","journal-title":"J. Polym. Sci. Part B Polym. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Wang, Y., Chen, R., Cai, J.Y., Liu, Z., Zheng, Y., Wang, H., Li, Q., and He, N. (2013). Biosynthesis and Thermal Properties of PHBV Produced from Levulinic Acid by Ralstonia Eutropha. PLoS ONE, 8.","DOI":"10.1371\/journal.pone.0060318"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"117521","DOI":"10.1016\/j.seppur.2020.117521","article-title":"Recovering PHA from Mixed Microbial Biomass: Using Non-Ionic Surfactants as a Pretreatment Step","volume":"253","author":"Colombo","year":"2020","journal-title":"Sep. Purif. Technol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"6893","DOI":"10.1016\/S0032-3861(02)00615-8","article-title":"In Situ FTIR Study on Melting and Crystallization of Polyhydroxyalkanoates","volume":"43","author":"Xu","year":"2002","journal-title":"Polymer"},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"1207","DOI":"10.1007\/s00216-007-1337-5","article-title":"Fourier-Transform Infrared (FTIR) Spectroscopy for Monitoring and Determining the Degree of Crystallisation of Polyhydroxyalkanoates (PHAs)","volume":"388","author":"Kansiz","year":"2007","journal-title":"Anal. Bioanal. Chem."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1016\/j.biortech.2015.03.062","article-title":"Extraction of Polyhydroxyalkanoates from Mixed Microbial Cultures: Impact on Polymer Quality and Recovery","volume":"189","author":"Abbondanzi","year":"2015","journal-title":"Bioresour. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"693","DOI":"10.1007\/s13399-020-00788-w","article-title":"Downstream Processing and Characterization of Polyhydroxyalkanoates (PHAs) Produced by Mixed Microbial Culture (MMC) and Organic Urban Waste as Substrate","volume":"11","author":"Lorini","year":"2021","journal-title":"Biomass Convers. Biorefinery"}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/14\/11\/2155\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T23:18:47Z","timestamp":1760138327000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/14\/11\/2155"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,5,25]]},"references-count":35,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2022,6]]}},"alternative-id":["polym14112155"],"URL":"https:\/\/doi.org\/10.3390\/polym14112155","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,5,25]]}}}