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Preliminary Investigation of Upcycling Polylactic Acid 3-D Printing Waste to Candidate Single-Cell Protein Feedstock

  • Laura Danier 1,   
  • Joshua M. Pearce 2,3,*

Received: 15 Mar 2026 | Revised: 01 Jun 2026 | Accepted: 08 Jun 2026 | Published: 12 Jun 2026

Abstract

Polylactic acid (PLA) is the most common extrusion-based distributed 3-D printing material. Unfortunately, large amounts of PLA are wasted from failed prints, support materials, material changes for multi-color printing, and poorly designed iterative prototypes. To overcome this waste challenge, distributed recycling with recyclebot technology is used to convert 3-D printing waste back into filament. This process can only be repeated five times before serious mechanical degradation of the resulting materials is observed. To overcome these challenges at the end-of-life of PLA 3-D printing material, this preliminary study explores a new approach that uses hydrolysis of PLA to create a candidate single-cell protein (SCP) feedstock that can be converted to human-edible food after required safety validation. Three concentrations of sodium hydroxide (NaOH) are tested for their ability to perform hydrolysis on PLA at room temperature using readily accessible equipment and chemicals. The solution is then neutralized, and yeast is grown in an open-source bioreactor, dried, and quantified to determine the preliminary yield of SCP. The results show a clear positive correlation between PLA degradation efficiency with higher NaOH concentration and yeast biomass production. The average performance of the 0.33 g NaOH/g PLA treatment resulted in an 8.5-fold yeast biomass increase. In summary, the current bench-scale process has proven technically viable and may be an economically justified method of yeast production on the household scale using PLA waste as a starting material. The dominant cost is energy, not reagents, which also lends the positive early results to future safety investigation using a scaled-up bioreactor.

References 

  • 1.

    Gibb, A. Building Open Source Hardware: DIY Manufacturing for Hackers and Makers; Addison-Wesley Professional: Boston, MA, USA, 2014; ISBN 978-0-13-337390-5.

  • 2.

    Bowyer, A. 3D Printing and Humanity’s First Imperfect Replicator. 3D Print. Addit. Manuf. 2014, 1, 4–5. https://doi.org/10.1089/3dp.2013.0003.

  • 3.

    Kotuła, S.D. Implementation of 3D Printing in an Open-Source Solution in an Academic Library. J. Acad. Librariansh. 2023, 49, 102768. https://doi.org/10.1016/j.acalib.2023.102768.

  • 4.

    75+ 3D Printing Statistics and Trends to Follow in 2025. Available online: https://learn.g2.com/3d-printing-statistics (accessed on 6 March 2026).

  • 5.

    Wittbrodt, B.T.; Glover, A.G.; Laureto, J.; et al. Life-Cycle Economic Analysis of Distributed Manufacturing with Open-Source 3-D Printers. Mechatronics 2013, 23, 713–726. https://doi.org/10.1016/j.mechatronics.2013.06.002.

  • 6.

    Pearce, J.; Qian, J.-Y. Economic Impact of DIY Home Manufacturing of Consumer Products with Low-Cost 3D Printing from Free and Open Source Designs. Eur. J. Soc. Impact Circ. Econ. 2022, 3, 1–24. https://doi.org/10.13135/2704-9906/6508.

  • 7.

    Pearce, J.M. Building Research Equipment with Free, Open-Source Hardware. Science 2012, 337, 1303–1304. https://doi.org/10.1126/science.1228183.

  • 8.

    Pearce, J.M. Return on Investment for Open Source Scientific Hardware Development. Sci. Public Policy 2016, 43, 192–195. https://doi.org/10.1093/scipol/scv034.

  • 9.

    Petersen, E.E.; Kidd, R.W.; Pearce, J.M. Impact of DIY Home Manufacturing with 3D Printing on the Toy and Game Market. Technologies 2017, 5, 45. https://doi.org/10.3390/technologies5030045.

  • 10.

    Kostakis, V.; Papachristou, M. Commons-Based Peer Production and Digital Fabrication: The Case of a RepRap-Based, Lego-Built 3D Printing-Milling Machine. Telemat. Inform. 2014, 31, 434–443. https://doi.org/10.1016/j.tele.2013.09.006.

  • 11.

    Romero, L.; Guerrero, A.; Espinosa, M.M.; et al. Additive Manufacturing with RepRap Methodology: Current Situation and Future Prospects. 2014. Available online: https://www.researchgate.net/publication/275886989_Additive_manufacturing_with_RepRap_methodology_current_situation_and_future_prospects (accessed on 6 March 2026).

  • 12.

    Jones, R.; Haufe, P.; Sells, E.; et al. RepRap—The Replicating Rapid Prototyper. Robotica 2011, 29, 177–191. https://doi.org/10.1017/S026357471000069X.

  • 13.

    Sells, E.; Bailard, S.; Smith, Z.; et al. RepRap: The Replicating Rapid Prototyper: Maximizing Customizability by Breeding the Means of Production. In Handbook of Research in Mass Customization and Personalization; World Scientific Publishing Company: Singapore, 2009; pp. 568–580; ISBN 978-981-4280-25-9.

  • 14.

    Abdullah, A.M. Preparation and Characterization of PLA Filaments for FDM 3D Printing. JMechE 2025, 22, 223–232. https://doi.org/10.24191/jmeche.v22i1.4566.

  • 15.

    Joseph, T.M.; Kallingal, A.; Suresh, A.M.; et al. 3D Printing of Polylactic Acid: Recent Advances and Opportunities. Int. J. Adv. Manuf. Technol. 2023, 125, 1015–1035. https://doi.org/10.1007/s00170-022-10795-y.

  • 16.

    Kreiger, M.; Pearce, J.M. Environmental Life Cycle Analysis of Distributed Three-Dimensional Printing and Conventional Manufacturing of Polymer Products. ACS Sustain. Chem. Eng. 2013, 1, 1511–1519. https://doi.org/10.1021/sc400093k.

  • 17.

    Madhu, N.R.; Erfani, H.; Jadoun, S.; et al. Fused Deposition Modelling Approach Using 3D Printing and Recycled Industrial Materials for a Sustainable Environment: A Review. Int. J. Adv. Manuf. Technol. 2022, 122, 2125–2138. https://doi.org/10.1007/s00170-022-10048-y.

  • 18.

    Phutela, V.; Juneja, S. Innovative Approaches to Recycling and Waste Reduction in 3D Printing. Int. J. Environ. Sci. Technol. 2025, 22, 17551–17568. https://doi.org/10.1007/s13762-025-06722-9.

  • 19.

    Song, R.; Telenko, C. Material and Energy Loss Due to Human and Machine Error in Commercial FDM Printers. J. Clean. Prod. 2017, 148, 895–904. https://doi.org/10.1016/j.jclepro.2017.01.171.

  • 20.

    Baechler, C.; DeVuono, M.; Pearce, J.M. Distributed Recycling of Waste Polymer into RepRap Feedstock. Rapid Prototyp. J. 2013, 19, 118–125. https://doi.org/10.1108/13552541311302978.

  • 21.

    Woern, A.L.; McCaslin, J.R.; Pringle, A.M.; et al. RepRapable Recyclebot: Open Source 3-D Printable Extruder for Converting Plastic to 3-D Printing Filament. HardwareX 2018, 4, e00026. https://doi.org/10.1016/j.ohx.2018.e00026.

  • 22.

    Zhong, S.; Pearce, J.M. Tightening the Loop on the Circular Economy: Coupled Distributed Recycling and Manufacturing with Recyclebot and RepRap 3-D Printing. Resour. Conserv. Recycl. 2018, 128, 48–58. https://doi.org/10.1016/j.resconrec.2017.09.023.

  • 23.

    Zhong, S.; Rakhe, P.; Pearce, J.M. Energy Payback Time of a Solar Photovoltaic Powered Waste Plastic Recyclebot System. Recycling 2017, 2, 10. https://doi.org/10.3390/recycling2020010.

  • 24.

    Dertinger, S.C.; Gallup, N.; Tanikella, N.G.; et al. Technical Pathways for Distributed Recycling of Polymer Composites for Distributed Manufacturing: Windshield Wiper Blades. Resour. Conserv. Recycl. 2020, 157, 104810. https://doi.org/10.1016/j.resconrec.2020.104810.

  • 25.

    Cruz Sanchez, F.A.; Boudaoud, H.; Camargo, M.; et al. Plastic Recycling in Additive Manufacturing: A Systematic Literature Review and Opportunities for the Circular Economy. J. Clean. Prod. 2020, 264, 121602. https://doi.org/10.1016/j.jclepro.2020.121602.

  • 26.

    Al Rashid, A.; Koç, M. Additive Manufacturing for Sustainability and Circular Economy: Needs, Challenges, and Opportunities for 3D Printing of Recycled Polymeric Waste. Mater. Today Sustain. 2023, 24, 100529. https://doi.org/10.1016/j.mtsust.2023.100529.

  • 27.

    Kreiger, M.; Anzalone, G.C.; Mulder, M.L.; et al. Distributed Recycling of Post-Consumer Plastic Waste in Rural Areas. MRS Online Proc. Libr. 2013, 1492, 91–96. https://doi.org/10.1557/opl.2013.258.

  • 28.

    Kreiger, M.A.; Mulder, M.L.; Glover, A.G.; et al. Life Cycle Analysis of Distributed Recycling of Post-Consumer High Density Polyethylene for 3-D Printing Filament. J. Clean. Prod. 2014, 70, 90–96. https://doi.org/10.1016/j.jclepro.2014.02.009.

  • 29.

    Sibille, A.; Ashkbous, M.; Doublet, L.H.C.; et al. The Sustainability of Recycled Polylactic Acid via Fused Filament Fabrication: Environmental Impacts across Cycles. Int. J. Adv. Manuf. Technol. 2025, 137, 1915–1928. https://doi.org/10.1007/s00170-025-15281-9.

  • 30.

    Hidalgo-Carvajal, D.; Muñoz, Á.H.; Garrido-González, J.J.; et al. Recycled PLA for 3D Printing: A Comparison of Recycled PLA Filaments from Waste of Different Origins after Repeated Cycles of Extrusion. Polymers 2023, 15, 3651. https://doi.org/10.3390/polym15173651.

  • 31.

    Lee, D.; Lee, Y.; Kim, I.; et al. Thermal and Mechanical Degradation of Recycled Polylactic Acid Filaments for Three-Dimensional Printing Applications. Polymers 2022, 14, 5385. https://doi.org/10.3390/polym14245385.

  • 32.

    Fleischmann’s Quick Rise Instant Yeast Strips—Walmart.Ca. Available online: https://www.walmart.ca/en/ip/Fleischmann-s-Quick-Rise-Instant-Yeast-Strips/10278673 (accessed on 6 March 2026).

  • 33.

    How Much Do 3D Prints Cost? Factors and Calculations—Eufymake US. Available online: https://www.eufymake.com/blogs/buying-guides/how-much-do-3d-prints-cost (accessed on 6 March 2026).

  • 34.

    Sodium Hydroxide Beads LYE NAOH 25KG Wholesale—Soap & More. Available online: https://soapandmore.ca/products/sodium-hydroxide-beads-lye-naoh-delivery-local-pickup-only (accessed on 6 March 2026).

  • 35.

    Powering Your Pioreactor Cluster | Pioreactor Docs. Available online: https://docs.pioreactor.com/user-guide/powering-cluster (accessed on 6 March 2026).

  • 36.

    Canada Electricity Prices, June 2025 | GlobalPetrolPrices.Com. Available online: https://www.globalpetrolprices.com/Canada/electricity_prices/ (accessed on 6 March 2026).

  • 37.

    Landfill Fees. Available online: https://www.greatersudbury.ca/live/garbage-and-recycling/landfill-and-transfer-stations/landfill-fees/ (accessed on 6 March 2026).

  • 38.

    BioShop Canada Inc. | LACTIC ACID, Reagent Grade. Available online: https://bioshopcanada.com/Products/Details/LAC660 (accessed on 6 March 2026).

  • 39.

    Wang, X.; Huang, L.; Li, Y.; et al. Research Progress in Polylactic Acid Processing for 3D Printing. J. Manuf. Process. 2024, 112, 161–178. https://doi.org/10.1016/j.jmapro.2024.01.038.

  • 40.

    Benhami, V.M.L.; de O. Longatti, S.M.; de S. Moreira, F.M.; et al. Biodegradation of Poly(Lactic Acid) Waste from 3D Printing. Polímeros 2024, 34, e20240013. https://doi.org/10.1590/0104-1428.20230058.

  • 41.

    Ghomi, E.R.; Khosravi, F.; Ardahaei, A.S.; et al. The Life Cycle Assessment for Polylactic Acid (PLA) to Make It a Low-Carbon Material. Polymers 2021, 13, 1854. https://doi.org/10.3390/polym13111854.

  • 42.

    O’Loughlin, J.; McDonnell, H.; Lawless, R.; et al. Manufacturing Process Significantly Impacts the Rate of Degradation of Polylactic Acid (PLA) under Controlled Composting Conditions. RSC Sustain. 2026, 4, 813–828. https://doi.org/10.1039/D5SU00623F.

  • 43.

    Gentile, M.; Gaeta, L.; Brenna, S.; et al. Efficient Chemical Recycling of Poly(L-Lactic Acid) via Either Alcoholysis to Alkyl Lactate or Thermal Depolymerization to L-Lactide Promoted by Zn(II) Catalysts. Polym. Test. 2025, 143, 108727. https://doi.org/10.1016/j.polymertesting.2025.108727.

  • 44.

    Ellis, S. Depolymerisation of Poly(Lactide) under Continuous Flow Conditions. Chem. Sci. 2024, 16, 211–217. https://doi.org/10.1039/d4sc05891g.

  • 45.

    Cederholm, L.; Wohlert, J.; Olsén, P.; et al. “Like Recycles Like”: Selective Ring-Closing Depolymerization of Poly(L-Lactic Acid) to L-Lactide. Angew. Chem. Int. Ed. 2022, 61, e202204531. https://doi.org/10.1002/anie.202204531.

  • 46.

    Cheng, L.; Chen, X.; Gu, J.; et al. Chemical Recycling of Waste Plastics: Current Challenges and Perspectives. Fundam. Res. 2025, 5, 919–922. https://doi.org/10.1016/j.fmre.2023.12.023.

  • 47.

    Moyaert, C.; Fozer, D.; Kovács, A.; et al. Prospective Life Cycle Assessment of End-of-Life Pathways for Polylactic Acid: Evaluating Environmental Trade-Offs and Technology Learning Potential. Sustain. Prod. Consum. 2026, 64, 15–36. https://doi.org/10.1016/j.spc.2026.01.014.

  • 48.

    Jubinville, D.; Tzoganakis, C.; Mekonnen, T.H. Recycled PLA—Wood Flour Based Biocomposites: Effect of Wood Flour Surface Modification, PLA Recycling, and Maleation. Constr. Build. Mater. 2022, 352, 129026. https://doi.org/10.1016/j.conbuildmat.2022.129026.

  • 49.

    Chien, Y.-C.; Wu, J.-H.; Shu, C.-H.; et al. Closed-Loop Recycling of 3D-Printed Wood–PLA Composite Parts: Effects on Mechanical and Structural Properties via Fused Filament Fabrication. Polymers 2024, 16, 3002. https://doi.org/10.3390/polym16213002.

  • 50.

    Pringle, A.M.; Rudnicki, M.; Pearce, J.M. Wood Furniture Waste–Based Recycled 3-D Printing Filament. For. Prod. J. 2018, 68, 86–95. https://doi.org/10.13073/FPJ-D-17-00042.

  • 51.

    Ilyas, R.A.; Sapuan, S.M.; Harussani, M.M.; et al. Polylactic Acid (PLA) Biocomposite: Processing, Additive Manufacturing and Advanced Applications. Polymers 2021, 13, 1326. https://doi.org/10.3390/polym13081326.

  • 52.

    Ramesh, M.; Rajeshkumar, L.; Sasikala, G.; et al. A Critical Review on Wood-Based Polymer Composites: Processing, Properties, and Prospects. Polymers 2022, 14, 589. https://doi.org/10.3390/polym14030589.

  • 53.

    Trivedi, A.K.; Gupta, M.K.; Singh, H. PLA Based Biocomposites for Sustainable Products: A Review. Adv. Ind. Eng. Polym. Res. 2023, 6, 382–395. https://doi.org/10.1016/j.aiepr.2023.02.002.

  • 54.

    Heikkinen, I.T.S.; Kauppinen, C.; Liu, Z.; et al. Chemical Compatibility of Fused Filament Fabrication-Based 3-D Printed Components with Solutions Commonly Used in Semiconductor Wet Processing. Addit. Manuf. 2018, 23, 99–107. https://doi.org/10.1016/j.addma.2018.07.015.

  • 55.

    21 CFR Part 170—Food Additives. Available online: https://www.ecfr.gov/current/title-21/part-170 (accessed on 27 May 2026).

  • 56.

    21 CFR Part 170 Subpart E—Generally Recognized as Safe (GRAS) Notice. Available online: https://www.ecfr.gov/current/title-21/part-170/subpart-E (accessed on 29 May 2026).

  • 57.

    21 CFR Part 507—Current Good Manufacturing Practice, Hazard Analysis, and Risk-Based Preventive Controls for Food for Animals. Available online: https://www.ecfr.gov/current/title-21/part-507 (accessed on 29 May 2026).

  • 58.

    Tedla, G.; Rogers, K. Characterization of 3D printing filaments containing metal additives and their particulate emissions. Sci. Total Environ. 2023, 875, 162648. https://doi.org/10.1016/j.scitotenv.2023.162648.

  • 59.

    Commission Implementing Regulation (EU) 2022/196 of 11 February 2022 Authorising an Extension of Use and the Change of the Specifications of UV-Treated Baker’s Yeast (Saccharomyces cerevisiae) as a Novel Food under Regulation (EU) 2015/2283 of the European Parliament and of the Council, and Amending Commission Implementing Regulation (EU) 2017/2470. Available online: https://eur-lex.europa.eu/eli/reg_impl/2022/196/oj/eng (accessed on 29 May 2026).

  • 60.

    FDA’s Final Guidance for AAFCO-Defined Ingredients. AAFCO. Available online: https://www.aafco.org/news/fdas-final-guidance-for-aafco-defined-ingredients/ (accessed on 29 May 2026).

  • 61.

    Medicine C for V. FDA. FDA; 2024. Generally Recognized as Safe (GRAS) Notification Program. Available online: https://www.fda.gov/animal-veterinary/animal-foods-feeds/generally-recognized-safe-gras-notification-program (accessed on 29 May 2026).

  • 62.

    National Research Council (NRC) Reports | National Animal Nutrition Program. Available online: https://animalnutrition.org/nrc_reports (accessed on 29 May 2026).

  • 63.

    Agency CFI. Novel feeds. 2015. Available online: http://inspection.canada.ca/en/animal-health/livestock-feeds/novel-feeds (accessed on 29 May 2026).

  • 64.

    OECD. Omics technologies in chemical testing. Available online: https://www.oecd.org/en/topics/sub-issues/testing-of-chemicals/omics-technologies-chemical-testing.html (accessed on 29 May 2026).

  • 65.

    Standards | CODEXALIMENTARIUS FAO-WHO. Available online: https://www.fao.org/fao-who-codexalimentarius/codex-texts/list-standards/en/ (accessed on 29 May 2026).

  • 66.

    Qualified presumption of safety (QPS) | EFSA. Available online: https://www.efsa.europa.eu/en/topics/topic/qualified-presumption-safety-qps (accessed on 29 May 2026).

  • 67.

    Undesirable substances—Food Safety—European Commission. Available online: https://food.ec.europa.eu/food-safety/animal-feed/undesirable-substances_en (accessed on 29 May 2026).

  • 68.

    Pearce, J.M. Expanding the Consumer Bill of Rights for Material Ingredients. Mater. Today 2018, 21, 197–198. https://doi.org/10.1016/j.mattod.2018.02.002.

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DOI
10.53941/fsp.2026.100009
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Volume 2, Issue 2
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Danier, L.; Pearce, J. M. Preliminary Investigation of Upcycling Polylactic Acid 3-D Printing Waste to Candidate Single-Cell Protein Feedstock. Food Science and Processing 2026, 2 (2), 9. https://doi.org/10.53941/fsp.2026.100009.
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