Table of Contents

    Topic review

    Biological Degradation of Polymers

    Subjects: Polymer Science
    View times: 92
    Submitted by: Silvia Kliem


    Biodegradable plastics can make an important contribution to the struggle against increasing environmental pollution through plastics. This entry provides an overview of the main environmental conditions in which biodegradation takes place and then presents the degradability of numerous polymers. 

    1. Introduction

    Plastics have become an indispensable part of everyday life. The various strengths of plastics come into their own in a wide variety of applications—packaging, clothing, car tires and much more. At the same time, however, the often-desired resistance to environmental influences and other stresses represents a major challenge. Plastic waste is increasingly found in the oceans, in rivers and in the ground, mostly as a result of human misconduct. Animals and humans ingest plastic particles with their food; the consequences are not yet foreseeable[1]. Rethinking of society is required in order to reduce the further input of plastics into the environment[2].

    Numerous research projects deal with the biological degradation of various polymers under different environmental conditions. The aim of this review is to provide a comprehensive overview of studies on the biological degradation of the most important biopolymers and to prove the necessary conditions for the successful degradation of each polymer on the basis of literature data. First, the definition and the influencing factors of biological degradation will be discussed.


    2. Biological Degradation

    Biological degradation is understood as the degradation of complex organic matter into carbon dioxide, methane, water, minerals and new biomass by means of a biological metabolic process[7]. This is achieved by the enzymatic activity of certain microorganisms, in particular bacteria and fungi, which first colonize the surface of the plastic and secrete a biofilm of specific enzymes. The excreted enzymes split the long polymer chains into short chain fragments, which are transported by means of tunnel proteins in the cell wall into the interior of the microorganism where they can be metabolized[10].

    The degradation behavior depends on numerous factors, which are shown in Table 1.

    Table 1. Major influential factors for biological degradation.

    Physicochemical Conditions

    Material Properties

    Enzymatic Effects

    Moisture/water content

    pH value


    Availability of oxygen

    Availability of nutrients

    Redox potential

    Molar mass

    Polymer composition

    Steric configuration

    Size, shape and surface area

    Melting and glass transition temperature

    Polymer crystallinity


    Material thickness



    Microbial activity

    Microbial diversity

    Microbial population density

    In summary, these factors can be subdivided into the physicochemical conditions that are determined by the environment, the material properties of the polymer to be metabolized and the type of microorganisms present. Only if all listed conditions are measured and controlled, a reliable statement on the degradability of a material and a comparison between degradation processes are possible.

    The detailed presentation of all factors goes beyond the scope of one single review. In the environment, however, certain environments with comparable conditions for biodegradation can be identified, which will be presented in the following and considered further in this summary.

    The different environmental conditions with their most important parameters for biological degradation are summarized graphically in Figure 1.

    Figure 1. Overview of ambient conditions.

    For a direct comparison of corresponding studies, all of the above-mentioned parameters would always have to be investigated and reported. Since this is rarely the case, the statements in this review are to be understood only as a guideline.

    3. Polymers

    This review presents a detailed overview of the degradation of a variety of biodegradable polymers in the environments presented in the previous section. Polymers are often compounded for better processability or supplementary functionalities with additives (see Scheme 1).

    Scheme 1. The Value Chain from a Monomer to a Plastic Component[10].

    One has to keep in mind that these can also influence the biodegradation of matrix polymers. Since PLA is currently the focus of attention due to its ready availability, and the polyhydroxyalkanoates PHB and PHBV due to its ready degradability, these polymers are comprehensively presented. The remaining polymers are evaluated briefly. Due to the active research landscape in the field of biopolymers, this is only a snapshot and does not claim that only these polymers are biodegradable.

    4. Key Challenges for Biodegradation Tests

    At the beginning of this review, the large number of parameters which influence the biological degradation of polymers was discussed. The results from various experimental studies presented in the previous section show the difficulty in comparing these studies.

    In order to create analogies, clearly defined conditions are necessary. Due to the complexity and the high regional dependence, it is generally almost impossible to carry out reproducible investigations in the environment. In the laboratory, the necessary parameters are easier to record and control, so that standardized laboratory tests are advantageous for a comparison of the results. It is also indispensable to consider a defined period of time, as it is usually not known whether the degradation is linear or if the degradation rate changes over time. There are p. ex. studies which propose a three-step degradation process for PHB, whereas only two stages are distinguishable for PCL[131].

    Numerous studies use the parameter of total mass loss to assess biodegradability. The mass loss, however, is not only caused by degradation but is also influenced by other parameters, such as currents, UV light and thermal or mechanical stress. According to ASTM D6400[6], ISO 14855[7] and EN 13432:2000[5], biological degradation is defined by the amount of CO2 released. Further evaluation methods are: the measurement of the increase in surface, the microbial growth, the change in molar mass, chemical element analysis or a comparison of the mechanical characteristic values.

    Another aspect that has seldom received enough attention in previous studies is the sample material used. In addition to the chemical composition or the indication of a clear type designation, the geometric shape of the sample also has a major influence on the duration of degradation. A powder offers a high surface-to-volume ratio, which means that more microorganisms can settle on the polymer surface than in a compact tensile test specimen. Even films differ in thickness and surface roughness and thus offer different surface qualities for the colonization by microorganisms.

    5. Conclusion and Outlook

    Plastics in the environment have long since become a topic of worldwide interest. Plastics drift in the world’s oceans, pollute water and soil and have now been detected in remote areas such as the Arctic. This development has also left its mark on humans, even though the health consequences of this exposure to plastic particles cannot be foreseen. Biodegradable plastics can make a positive contribution, at least in applications that inevitably end up in the environment.

    The biological degradation depends on numerous environmental conditions; these are in addition to the prevailing physico-chemical conditions and the activity of existing microorganisms, especially the material properties of the considered plastic component. However, the most important environments can be summarized. The most favorable degradation conditions are found in composting environments. In home compost, as well as in industrial composting plants, there is a large microbial diversity with high activity, especially with a good oxygen supply. In the latter case, there are also increased temperatures, which further promote the activity of the microorganisms. Numerous microorganisms are still present in the soil and in sewage sludge, but the temperatures are partly subject to large regional fluctuations. Aqueous environments (fresh and seawater) show the lowest biological activity, because the water provides a strong dilution. In landfills, biological degradation takes place at a slower rate, and under the exclusion of oxygen, and is strongly dependent on the mode of operation.

    The aim of this review was to compare the biodegradability of biopolymers in various environments. The results are summarized in Figure 2.

    Figure 2. Biological degradation of different polymers in different environments.

    However, despite extensive literature on the subject, it is almost impossible to make generally valid statements. As mentioned above, the decisive factors for biodegradation are manifold and rarely documented in detail. In most cases, the available results differ or even contradict each other, making it impossible to specify a defined degradation period. In order to be able to make reliable statements, it is essential to clearly define specifications with regard to physico-chemical conditions, performance, test specimen geometry, etc. Possible standardizations are offered by the guidelines presented in the Appendix. In particular, however, the measured target must be standardized. Due to the aforementioned influencing factors on the total mass, only the determination of the biological degradation via the CO2 release allows a direct conclusion on the actual metabolism of a polymer.

    This comprehensive research of reviewed magazines was made after intensive discussions with the experts Michael Carus, nova institut Hürth, and Bruno de Wilde, OWS Gent. In order to give an overview of the breadth of the information gathered in this summary, the entire literature on which this work is based is given below.

    The entry is from 10.3390/ma13204586


    1. Barboza, L.G.A.; Dick Vethaak, A.; Lavorante, B.R.B.O.; Lundebye, A.-K.; Guilhermino, L. Marine microplastic debris: An emerging issue for food security, food safety and human health. Mar. Pollut. Bull. 2018, 133, 336–348.
    2. Göttermann, S.; Bonten, C.; Kloeppel, A.; Kaiser, S.; Brümmer, F. Marine littering -auswirkung und abbauverhalten. In Proceedings of the 24. Stuttgarter Kunststoffkolloquium, Stuttgart, Germany, 25–26. February 2015.
    3. Ellen MacArthur Foundation. The New Plastics Economy: Rethinking the Future of Plastics & Catalysing Action; Ellen MacArthur Foundation, Cowes, United Kingdom: 2017; pp. 1–68.
    4. Ißbrücker, C.; Pogrell, H.V. Biobasiert, bioabbaubar oder beides. Nachr. Chem. 2013, 61, 1037–1038.
    5. Deutsches Institut für Normung DIN EN 13432. Verpackung—Anforderungen an die Verwertung von Verpackungen durch Kompostierung und biologischen Abbau—Prüfschema und Bewertungskriterien für die Einstufung von Verpackungen. Dtsch. Fass. EN 2000, 13432, 2007–2010.
    6. American Society for Testing. Materials ASTM D6400. In Standard Specification for Labeling of Plastics Designed to be Aerobically Composted in Municipal or Industrial Facilities; ASTM International, West Conshohocken, PA, 2019.
    7. Deutsches Institut für Normung E.V. DIN EN ISO 14855-1. Bestimmung der vollständigen aeroben Bioabbaubarkeit von Kunststoff-Materialien unter den Bedingungen kontrollierter Kompostierung; Deutsches Institut für Normung E.V. DIN EN ISO 14855-1.
    8. Augusta, J.; Müller, R.-J.; Widdecke, H. Biologisch abbaubare Kunststoffe: Testverfahren und Beurteilungskriterien. Chem. Ing. Tech. 1992, 64, 410–415.
    9. Zumstein, M.T.; Schintlmeister, A.; Nelson, T.F.; Baumgartner, R.; Woebken, D.; Wagner, M.; Kohler, H.-P.E.; McNeill, K.; Sander, M. Biodegradation of synthetic polymers in soils: Tracking carbon into CO2 and microbial biomass. Sci. Adv. 2018, 4, eaas9024.
    10. Bonten, C. Plastics Technology: Introduction and Fundamentals; Carl Hanser Verlag GmbH Co KG: Munich, Germany, 2019. ISBN 978-1-56990-767-2.
    11. Chahine, M.T. The hydrological cycle and its influence on climate. Nature 1992, 359, 373–380.
    12. Munn, C.B. Marine Microbiology: Ecology and Applications; Garland Science/BIOS Scientific Publishers and Distributed in the USA by Fulfilment Center, Taylor & Francis: London, UK; New York, NY, USA; Independence, KY, USA, 2004. ISBN 978-0-203-50311-9.
    13. Alyn, C.; Duxbury Fred, T. Mackenzie, Robert und Howard Byrne; Encylopeadia Britannica Inc.: Chicago, IL, USA, 2018.
    14. Chen, R.; Jakes, K.A. Cellulolytic Biodegradation of Cotton Fibers from a Deep-Ocean Environment. J. Am. Inst. Conserv. 2001, 40, 91–103.
    15. Alexopoulos, A.; Plessas, S.; Bezirtzoglou, E. Water microbial ecology—An overview. Encyclopedia of Life Sci, 2009, pp. 1-24.
    16. Okafor, N. Environmental Microbiology of Aquatic and Waste Systems; Springer Science + Business Media B.V: Dordrecht, The Netherlands, 2011. ISBN 978-94-007-1459-5.
    17. Necker, J. Einfluss neozoischer Crustaceen auf Invertebrate des Bodenseelitorals. 2006. Available online: (accessed on 01.09.2020).
    18. Gordon & Breach. The limnology, climatology and paleoclimatology of the East African Lakes; Johnson, T.C., Ed.; Gordon & Breach: Amsterdam, The Netherlands, 1996. ISBN 2-88449-234-8.
    19. Boyd, C.E.; Tucker, C.S. Pond Aquaculture Water Quality Management; Springer: Boston, MA, USA, 1998. ISBN 1461554071.
    20. Bastioli, C. Handbook of Biodegradable Polymers; Rapra Technology: Shrewsbury, UK, 2005. ISBN 1-85957-389-4.
    21. Scheunert, I. Mikrobieller Abbau organischer Fremdstoffe im Boden. Chem. Unserer Zeit 1994, 28, 68–78.
    22. Organisation for Economic Co-Operation; Development OECD 301A. Test No. 307: Aerobic and Anaerobic Transformation in Soil; OECD Publishing: Paris, France, 2002.
    23. Rudnik, E. Compostable Polymer Materials, 1st ed.; Elsevier: Amsterdam, The Netherlands, 2008. ISBN 9780080453712.
    24. TUEV AUSTRIA HOLDING AG 2019. OK Compost Home. Available online: (accessed on 01.09.2020).
    25. Auras, R.; Harte, B.; Selke, S. An overview of polylactides as packaging materials. Macromol. Biosci. 2004, 4, 835–864.
    26. Hermann, B.G.; Debeer, L.; de Wilde, B.; Blok, K.; Patel, M.K. To compost or not to compost: Carbon and energy footprints of biodegradable materials’ waste treatment. Polym. Degrad. Stab. 2011, 96, 1159–1171.
    27. Mateo-Sagasta, J.; Raschid-Sally, L.; Thebo, A. Global Wastewater and Sludge Production, Treatment and Use. In Wastewater: Economic Asset in an Urbanizing World; Qadir, M., Wichelns, D., Drechsel, P., Eds.; Springer: Dordrecht, The Netherlands; Heidelberg, Germany; New York, NY, USA, 2015; pp 15–38, ISBN 978-94-017-9545-6.
    28. Poulsen, T.G.; Bester, K. Organic micropollutant degradation in sewage sludge during composting under thermophilic conditions. Environ. Sci. Technol. 2010, 44, 5086–5091.
    29. American Society for Testing. Materials ASTM AST 5209-92; ASTM International, Philadelphia, PA, 1992..
    30. Renou, S.; Givaudan, J.G.; Poulain, S.; Dirassouyan, F.; Moulin, P. Landfill leachate treatment: Review and opportunity. J. Hazard. Mater. 2008, 150, 468–493.
    31. Reinhart, D.R.; Basel Al-Yousfi, A. The Impact of Leachate Recirculation on Municipal Solid Waste Landfill Operating Characteristics. Waste Manag. Res. 2016, 14, 337–346, doi:10.1177/0734242X9601400402.
    32. Domininghaus, H.; Elsner, P.; Eyerer, P.; Hirth, T. Kunststoffe: Eigenschaften und Anwendungen, 8., neu bearb. und erw. Aufl.; Springer: Berlin/Heidelberg, Germany, 2012. ISBN 9783642161728.
    33. Türk, O. Stoffliche Nutzung Nachwachsender Rohstoffe: Grundlagen—Werkstoffe—Anwendungen; Springer Fachmedien Wiesbaden: Wiesbaden, Germany, 2014. ISBN 9783834817631.
    34. Kolstad, J.J.; Vink, E.T.H.; de Wilde, B.; Debeer, L. Assessment of anaerobic degradation of Ingeo™ polylactides under accelerated landfill conditions. Polym. Degrad. Stab. 2012, 97, 1131–1141, doi:10.1016/j.polymdegradstab.2012.04.003.
    35. Tsuji, H.; Suzuyoshi, K. Environmental degradation of biodegradable polyesters 2. Poly(ε-caprolactone), poly[(R)-3-hydroxybutyrate], and poly(L-lactide) films in natural dynamic seawater. Polym. Degrad. Stab. 2002, 75, 357–365.
    36. Bagheri, A.R.; Laforsch, C.; Greiner, A.; Agarwal, S. Fate of So-Called Biodegradable Polymers in Seawater and Freshwater. Glob. Chall. 2017, 1, 1700048.
    37. Karamanlioglu, M.; Robson, G.D. The influence of biotic and abiotic factors on the rate of degradation of poly(lactic) acid (PLA) coupons buried in compost and soil. Polym. Degrad. Stab. 2013, 98, 2063–2071.
    38. Rudnik, E.; Briassoulis, D. Degradation behaviour of poly(lactic acid) films and fibres in soil under Mediterranean field conditions and laboratory simulations testing. Ind. Crop. Prod. 2011, 33, 648–658.
    39. Ho, K.-L.G.; Pometto III, A.L.; Gadea-Rivas, A.; Briceño, J.A.; Rojas, A. Degradation of Polylactic Acid (PLA) Plastic in Costa Rican Soil and Iowa State University Compost Rows. J. Polym. Environ. 1999, 7, 173–177.
    40. Sikorska, W.; Musiol, M.; Nowak, B.; Pajak, J.; Labuzek, S.; Kowalczuk, M.; Adamus, G. Degradability of polylactide and its blend with poly[(R,S)-3-hydroxybutyrate] in industrial composting and compost extract. Int. Biodeterior. Biodegrad. 2015, 101, 32–41.
    41. Yosita, R.; Jaruayporn, N.; Monchai, T.; Phasawat, C.; Thanawadee, L. Determining Biodegradability of Polylactic Acid under Different Environments. J. Met. Mater. Miner. 2008, 18, 83–87.
    42. Yagi, H.; Ninomiya, F.; Funabashi, M.; Kunioka, M. Mesophilic anaerobic biodegradation test and analysis of eubacteria and archaea involved in anaerobic biodegradation of four specified biodegradable polyesters. Polym. Degrad. Stab. 2014, 110, 278–283.
    43. Yagi, H.; Ninomiya, F.; Funabashi, M.; Kunioka, M. Thermophilic anaerobic biodegradation test and analysis of eubacteria involved in anaerobic biodegradation of four specified biodegradable polyesters. Polym. Degrad. Stab. 2013, 98, 1182–1187.
    44. Behr, A.; Seidensticker, T. Einführung in die Chemie nachwachsender Rohstoffe: Vorkommen, Konversion, Verwendung; Springer Spektrum: Berlin/Heidelberg, Germany, 2018. ISBN 9783662552544.
    45. Ansari, S.; Fatma, T. Polyhydroxybutyrate—A Biodegradable Plastic and its Various Formulations. Int. J. Innov. Res. Sci. Eng. Technol. 2014, 3, 9598–9602.
    46. Volova, T.G.; Boyandin, A.N.; Vasiliev, A.D.; Karpov, V.A.; Prudnikova, S.V.; Mishukova, O.V.; Boyarskikh, U.A.; Filipenko, M.L.; Rudnev, V.P.; Bá Xuân, B.; et al. Biodegradation of polyhydroxyalkanoates (PHAs) in tropical coastal waters and identification of PHA-degrading bacteria. Polym. Degrad. Stab. 2010, 95, 2350–2359.
    47. Mergaert, J.; Wouters, A.; Anderson, C.; Swings, J. In situ biodegradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in natural waters. Can. J. Microbiol. 1995, 41 (Suppl. 1), 154–159.
    48. Mergaert, J.; Webb, A.; Anderson, C.; Wouters, A.; Swings, J. Microbial degradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in soils. Appl. Environ. Microbiol. 1993, 59, 3233–3238.
    49. Boyandin, A.N.; Prudnikova, S.V.; Karpov, V.A.; Ivonin, V.N.; Đỗ, N.L.; Nguyễn, T.H.; Lê, T.M.H.; Filichev, N.L.; Levin, A.L.; Filipenko, M.L.; et al. Microbial degradation of polyhydroxyalkanoates in tropical soils. Int. Biodeterior. Biodegrad. 2013, 83, 77–84.
    50. Mergaert, J.; Anderson, C.; Wouters, A.; Swings, J. Microbial degradation of poly(3-hydroxybutyrate) and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in compost. J. Environ. Polym. Degrad. 1994, 2, 177–183.
    51. Tabasi, R.Y.; Ajji, A. Selective degradation of biodegradable blends in simulated laboratory composting. Polym. Degrad. Stab. 2015, 120, 435–442.
    52. Puglia, D.; Fortunati, E.; D’Amico, D.A.; Manfredi, L.B.; Cyras, V.P.; Kenny, J.M. Influence of organically modified clays on the properties and disintegrability in compost of solution cast poly(3-hydroxybutyrate) films. Polym. Degrad. Stab. 2014, 99, 127–135.
    53. Gutierrez-Wing, M.T.; Stevens, B.E.; Theegala, C.S.; Ioan, I. Anaerobic Biodegradation of Polyhydroxybutyrate in Municipal Sewage Sludge. J. Environ. Eng. 2010, 136, 709–718.
    54. Nishida, H.; Tokiwa, Y. Distribution of poly(β-hydroxybutyrate) and poly(ε-caprolactone)aerobic degrading microorganisms in different environments. J. Environ. Polym. Degrad. 1993, 1, 227–233.
    55. Tansengco, M.; Dogma, I. Microbial degradation of poly-β-hydroxybutyrate using landfill soils. Acta Biotechnol. 1999, 19, 191–203.
    56. Matavulj, M.; Sad, N.; Molitoris, H.P. Biodegradation of polyhydroxyalkanoate-based plastic (BIOPOL) under different environmental conditions I. weight loss of substrate. Hoppea 2000, 61, 735–749.
    57. Eubeler, J.P.; Zok, S.; Bernhard, M.; Knepper, T.P. Environmental biodegradation of synthetic polymers I. Test methodologies and procedures. TrAC Trends Anal. Chem. 2009, 28, 1057–1072.
    58. Luzier, W.D. Materials derived from biomass/biodegradable materials. Proc. Natl. Acad. Sci. USA 1992, 89, 839–842.
    59. Briese, B.H.; Jendrossek, D.; Schlegel, H.G. Degradation of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) by aerobic sewage sludge. FEMS Microbiol. Lett. 1994, 117, 107–111.
    60. Shin, P.K.; Kim, M.H.; Kim, J.M. Biodegradability of degradable plastics exposed to anaerobic digested sludge and simulated landfill conditions. J. Environ. Polym. Degrad. 1997, 5, 33–39.
    61. Rutkowska, M.; Krasowska, K.; Heimowska, A.; Steinka, I. Effect of Modification of Poly(ε-Caprolactone) on its Biodegradation in Natural Environments. Int. Polym. Sci. Technol. 2002, 29, 77–84.
    62. Heimowska, A.; Krasowska, K.; Rutkowska, M. Degradability of Different Packaging Polymeric Materials in Sea Water. Int. Polym. Sci. Technol. 2011, 1, 262–268.
    63. Bastioli, C.; Cerutti, A.; Guanella, I.; Romano, G.C.; Tosin, M. Physical state and biodegradation behavior of starch-polycaprolactone systems. J. Environ. Polym. Degrad. 1995, 3, 81–95.
    64. Yang, H.-S.; Yoon, J.-S.; Kim, M.-N. Dependence of biodegradability of plastics in compost on the shape of specimens. Polym. Degrad. Stab. 2005, 87, 131–135.
    65. Hoshino, A.; Sawada, H.; Yokota, M.; Tsuji, M.; Fukuda, K.; Kimura, M. Influence of weather conditions and soil properties on degradation of biodegradable plastics in soil. Soil Sci. Plant Nutr. 2001, 47, 35–43.
    66. Teramoto, N.; Urata, K.; Ozawa, K.; Shibata, M. Biodegradation of aliphatic polyester composites reinforced by abaca fiber. Polym. Degrad. Stab. 2004, 86, 401–409.
    67. Phua, Y.J.; Lau, N.S.; Sudesh, K.; Chow, W.S.; Mohd Ishak, Z.A. Biodegradability studies of poly(butylene succinate)/organo-montmorillonite nanocomposites under controlled compost soil conditions: Effects of clay loading and compatibiliser. Polym. Degrad. Stab. 2012, 97, 1345–1354.
    68. Zhao, J.-H.; Wang, X.-Q.; Zeng, J.; Yang, G.; Shi, F.-H.; Yan, Q. Biodegradation of poly(butylene succinate) in compost. J. Appl. Polym. Sci. 2005, 97, 2273–2278.
    69. Kim, H.-S.; Kim, H.-J.; Lee, J.-W.; Choi, I.-G. Biodegradability of bio-flour filled biodegradable poly(butylene succinate) bio-composites in natural and compost soil. Polym. Degrad. Stab. 2006, 91, 1117–1127.
    70. Muroi, F.; Tachibana, Y.; Kobayashi, Y.; Sakurai, T.; Kasuya, K.-I. Influences of poly(butylene adipate-co-terephthalate) on soil microbiota and plant growth. Polym. Degrad. Stab. 2016, 129, 338–346.
    71. Kijchavengkul, T.; Auras, R.; Rubino, M.; Alvarado, E.; Camacho Montero, J.R.; Rosales, J.M. Atmospheric and soil degradation of aliphatic-aromatic polyester films. Polym. Degrad. Stab. 2010, 95, 99–107.
    72. Wang, H.; Wei, D.; Zheng, A.; Xiao, H. Soil burial biodegradation of antimicrobial biodegradable PBAT films. Polym. Degrad. Stab. 2015, 116, 14–22.
    73. Bernhard, M.; Eubeler, J.P.; Zok, S.; Knepper, T.P. Aerobic biodegradation of polyethylene glycols of different molecular weights in wastewater and seawater. Water Res. 2008, 42, 4791–4801.
    74. Zgoła-Grześkowiak, A.; Grześkowiak, T.; Zembrzuska, J.; Łukaszewski, Z. Comparison of biodegradation of poly(ethylene glycol)s and poly(propylene glycol)s. Chemosphere 2006, 64, 803–809.
    75. Haines, J.R.; Alexander, M. Microbial Degradation of Polyethylene Glycols. Appl. Microbiol. 1975, 29, 621–625.
    76. Obradors, N.; Aguilar, J. Efficient biodegradation of high-molecular-weight polyethylene glycols by pure cultures of Pseudomonas stutzeri. Appl. Environ. Microbiol. 1991, 57, 2383–2388.
    77. Pérez, J.; Muñoz-Dorado, J.; La Rubia, T. de; Martínez, J. Biodegradation and biological treatments of cellulose, hemicellulose and lignin: An overview. Int. Microbiol. Off. J. Span. Soc. Microbiol. 2002, 5, 53–63.
    78. Florian, M.-L.E. The Underwater Environment—Conservation of Marine Archaeological Objects; Butterwort-Heinemann: Oxford, UK, 1987.
    79. Elsevier, Spektrum, Akad. Verl. Lexikon der Biologie; Elsevier, Spektrum, Akad. Verl.: Heidelberg/München, Germany, 2006. ISBN 3-8274-1736-8.
    80. Hofsten, B.V.; Edberg, N. Estimating the Rate of Degradation of Cellulose Fibers in Water. Oikos 1972, 23, 29.
    81. Lamot, E.; Voets, J.P. Microbial biodegradation of cellophane. Z. Für Allg. Mikrobiol. 1978, 18, 183–188.
    82. Endres, H.-J.; Siebert-Raths, A. Technische Biopolymere: Rahmenbedingungen, Marktsitutation, Herstellung, Aufbau und Eigenschaften; Hanser: München, Germany, 2009. ISBN 9783446416833.
    83. Itävaara, M.; Siika-aho, M.; Viikari, L. Enzymatic Degradation of Cellulose-Based Materials. J. Environ. Polym. Degrad. 1999, 7, 67–73, doi:10.1023/A:1021804216508.
    84. Ishigaki, T.; Sugano, W.; Nakanishi, A.; Tateda, M.; Ike, M.; Fujita, M. The degradability of biodegradable plastics in aerobic and anaerobic waste landfill model reactors. Chemosphere 2004, 54, 225–233.
    85. Buchanan, C.M.; Gardner, R.M.; Komarek, R.J. Aerobic biodegradation of cellulose acetate. J. Appl. Polym. Sci. 1993, 47, 1709–1719.
    86. Chen, H. Biotechnology of Lignocellulose; Springer: Dordrecht, The Netherlands, 2014. ISBN 978-94-007-6897-0.
    87. Wüstenberg, T. Cellulose und Cellulosederivate: Grundlagen, Wirkungen und Applikationen, 1. Aufl.; Behr: Hamburg, Germany, 2013. ISBN 9783954680191.
    88. National Oceanic and Atmospheric Administration Marine Debris Program. Director: Nancy Wallace. In Clean Guide; NOAA 101: Washington, DC, USA, 2018.
    89. Costa, S.; Dedola, D.; Pellizzari, S.; Blo, R.; Rugiero, I.; Pedrini, P.; Tamburini, E. Lignin Biodegradation in Pulp-and-Paper Mill Wastewater by Selected White Rot Fungi. Water 2017, 9, 935.
    90. Vikman, M.; Itävaara, M.; Poutanen, K. Biodegradation of Starch-Based Materials. J. Macromol. Sci. Part A 1995, 32, 863–866.
    91. Vaverková, M.; Toman, F.; Adamcová, D.; Kotovicová, J. Study of the Biodegrability of Degradable/Biodegradable Plastic Material in a Controlled Composting Environment. Ecol. Chem. Eng. S 2012, 19, 347–358.
    92. Torres, F.G.; Troncoso, O.P.; Torres, C.; Díaz, D.A.; Amaya, E. Biodegradability and mechanical properties of starch films from Andean crops. Int. J. Biol. Macromol. 2011, 48, 603–606.
    93. Guzman-Sielicka, A.; Janik, H.; Sielicki, P. Degradation of Polycaprolactone Modified with TPS or CaCO3 in Biotic/Abiotic Seawater. J. Environ. Polym. Degrad. 2012, 20, 353–360.
    94. Guzman, A.; Janik, H.; Mastalerz, M.; Kosakowska, A. Pilot study of the influence of thermoplastic starch based polymer packaging material on the growth of diatom population in sea water environment. Pol. J. Chem. Technol. 2011, 13, 57–61.
    95. Bootklad, M.; Kaewtatip, K. Biodegradation of thermoplastic starch/eggshell powder composites. Carbohydr. Polym. 2013, 97, 315–320.
    96. Zain, A.H.M.; Ab Wahab, M.K.; Ismail, H. Biodegradation Behaviour of Thermoplastic Starch: The Roles of Carboxylic Acids on Cassava Starch. J. Environ. Polym. Degrad. 2018, 26, 691–700.
    97. Vikman, M.; Itävaara, M.; Poutanen, K. Measurement of the biodegradation of starch-based materials by enzymatic methods and composting. J. Environ. Polym. Degrad. 1995, 3, 23–29.
    98. Di Franco, C.R.; Cyras, V.P.; Busalmen, J.P.; Ruseckaite, R.A.; Vázquez, A. Degradation of polycaprolactone/starch blends and composites with sisal fibre. Polym. Degrad. Stab. 2004, 86, 95–103.
    99. Mohee, R.; Unmar, G. Determining biodegradability of plastic materials under controlled and natural composting environments. Waste Manag. 2007, 27, 1486–1493.
    100. Vaz, C.M.; Fossen, M.; van Tuil, R.F.; Graaf, L.A.D.; Reis, R.L.; Cunha, A.M. Casein and soybean protein-based thermoplastics and composites as alternative biodegradable polymers for biomedical applications. J. Biomed. Mater. Res. Part A 2003, 65A, 60–70.
    101. CRC Press. Enzymes of Psychrotrophs in Raw Food; McKellar, R.C., MacKellar, R.C., Eds.; CRC Press: Boca Raton, FL, USA, 1989. ISBN 978-0-8493-6103-6.
    102. Mierau, I.; Kunji, E.R.; Venema, G.; Kok, J. Casein and peptide degradation in lactic acid bacteria. Biotechnol. Genet. Eng. Rev. 1997, 14, 279–301.
    103. Austin, B.; Austin, D. Bacterial Fish Pathogens: Disease of Farmed and Wild Fish; Springer: Dordrecht, The Netherlands, 2007. ISBN 9781402060687.
    104. Domenek, S.; Feuilloley, P.; Gratraud, J.; Morel, M.-H.; Guilbert, S. Biodegradability of wheat gluten based bioplastics. Chemosphere 2004, 54, 551–559.
    105. Park, S.K.; Hettiarachchy, N.S.; Were, L. Degradation behavior of soy protein-wheat gluten films in simulated soil conditions. J. Agric. Food Chem. 2000, 48, 3027–3031.
    106. Lim, S.W.; Jung, I.K.; Lee, K.H.; Jin, B.S. Structure and properties of biodegradable gluten/aliphatic polyester blends. Eur. Polym. J. 1999, 35, 1875–1881.
    107. John, J.; Tang, J.; Bhattacharya, M. Processing of biodegradable blends of wheat gluten and modified polycaprolactone. Polymer 1998, 39, 2883–2895.
    108. Zhang, X.; Gozukara, Y.; Sangwan, P.; Gao, D.; Bateman, S. Biodegradation of chemically modified wheat gluten-based natural polymer materials. Polym. Degrad. Stab. 2010, 95, 2309–2317.
    109. Hernández-Muñoz, P.; Kanavouras, A.; Ng, P.K.W.; Gavara, R. Development and characterization of biodegradable films made from wheat gluten protein fractions. J. Agric. Food Chem. 2003, 51, 7647–7654.
    110. Gutarowska, B.; Michalski, A. Microbial Degradation of Woven Fabrics and Protection Against Biodegradation; IntechOpen, Rijeka, Croatia: 2012. Available online: (accessed on 01.09.2020).
    111. Beverly H. Wool in Marine Environments; International Wool Textile Organisation: 2017.
    112. International Wool Textile Organisation. Wool is Biodegradable; Campaign Wool IWTO: Harrogate, UK, 2014.
    113. Jibia, S.A.; Mohanty, S.; Dondapati, J.S.; O’hare, S.; Rahman, P.K.S.M. Biodegradation of Wool by Bacteria and Fungi and Enhancement of Wool Quality by Biosurfactant Washing. J. Nat. Fibers 2018, 15, 287–295.
    114. McNeil, S.; Barker, H. The Biodegradability of Wool Enables Wool-to-Grass-to-Wool, Closed-Loop Recycling. Tech. Bull. AgRes. 2015.
    115. Du, L.C.; Meng, Y.Z.; Wang, S.J.; Tjong, S.C. Synthesis and degradation behavior of poly(propylene carbonate) derived from carbon dioxide and propylene oxide. J. Appl. Polym. Sci. 2004, 92, 1840–1846, doi:10.1002/app.20165.
    116. Bahramian, B.; Fathi, A.; Dehghani, F. A renewable and compostable polymer for reducing consumption of non-degradable plastics. Polym. Degrad. Stab. 2016, 133, 174–181.
    117. Luinstra, G. Poly(Propylene Carbonate), Old Copolymers of Propylene Oxide and Carbon Dioxide with New Interests: Catalysis and Material Properties. Polym. Rev. 2008, 48, 192–219.
    118. Dadsetan, M.; Christenson, E.M.; Unger, F.; Ausborn, M.; Kissel, T.; Hiltner, A.; Anderson, J.M. In vivo biocompatibility and biodegradation of poly(ethylene carbonate). J. Control. Release 2003, 93, 259–270.
    119. Kawaguchi, T.; Nakano, M.; Juni, K.; Inoue, S.; Yoshida, Y. Examination of Biodegradability of Poly (ethylene carbonate) and Poly (propylene carbonate) in the Peritoneal Cavity in Rats. Chem. Pharm. Bull. 1983, 31, 1400–1403.
    120. Ramlee, N.A.; Tominaga, Y. Preparation and characterization of poly(ethylene carbonate)/poly(lactic acid) blends. J. Polym. Res. 2018, 25, 263.
    121. Zhao, Y.-Q.; Cheung, H.-Y.; Lau, K.-T.; Xu, C.-L.; Zhao, D.-D.; Li, H.-L. Silkworm silk/poly(lactic acid) biocomposites: Dynamic mechanical, thermal and biodegradable properties. Polym. Degrad. Stab. 2010, 95, 1978–1987.
    122. Arai, T.; Freddi, G.; Innocenti, R.; Tsukada, M. Biodegradation ofBombyx mori silk fibroin fibers and films. J. Appl. Polym. Sci. 2004, 91, 2383–2390.
    123. Sato, K.; Azama, Y.; Nogawa, M.; Taguchi, G.; Shimosaka, M. Analysis of a change in bacterial community in different environments with addition of chitin or chitosan. J. Biosci. Bioeng. 2010, 109, 472–478.
    124. Krsek, M.; Wellington, E.M. Assessment of chitin decomposer diversity within an upland grassland. Antonie van Leeuwenhoek 2001, 79, 261–267.
    125. Nakashima, T.; Nakano, Y.; Bin, Y.; Matsuo, M. Biodegradation Characteristics of Chitin and Chitosan Films. J. Home Econ. Jpn. 2005, 56, 889–897.
    126. Sawaguchi, A.; Ono, S.; Oomura, M.; Inami, K.; Kumeta, Y.; Honda, K.; Sameshima-Saito, R.; Sakamoto, K.; Ando, A.; Saito, A. Chitosan degradation and associated changes in bacterial community structures in two contrasting soils. Soil Sci. Plant Nutr. 2015, 61, 471–480.
    127. Tuomela, M. Biodegradation of lignin in a compost environment: A review. Bioresour. Technol. 2000, 72, 169–183.
    128. Venelampi, O.; Weber, A.; Rönkkö, T.; Itävaara, M. The Biodegradation and Disintegration of Paper Products in the Composting Environment. Compos. Sci. Util. 2003, 11, 200–209.
    129. Vikman, M.; Karjomaa, S.; Kapanen, A.; Wallenius, K.; Itävaara, M. The influence of lignin content and temperature on the biodegradation of lignocellulose in composting conditions. Appl. Microbiol. Biotechnol. 2002, 59, 591–598.
    130. Saake, B.; Lehnen, R. Ullmann’s Encyclopedia of Industrial Chemistry; Wiley: Chichester, UK, 2010. ISBN 978-3-527-30673-2.
    131. Rosa, D.S.; Filho, R.P.; Chui, Q.S.H.; Calil, M.R.; Guedes, C.G.F. The biodegradation of poly-β-(hydroxybutyrate), poly-β-(hydroxybutyrate-co-β-valerate) and poly(ε-caprolactone) in compost derived from municipal solid waste. Eur. Polym. J. 2003, 39, 233–237.
    132. Development OECD 301A, Organisation for Economic Co-Operation. OECD Guideline for Testing of Chemicals; Development OECD 301A, Organisation for Economic Co-operation: Paris, France, 1992.
    133. TUEV AUSTRIA HOLDING AG 2019. OK Compost Industrial. Available online: (accessed on 01.09.2020).
    134. TUEV AUSTRIA HOLDING AG 2019. OK biodegradable Marine. Available online: (accessed on 01.09.2020).
    135. TUEV AUSTRIA HOLDING AG 2019. OK biodegradable Water. Available online: (accessed on 01.09.2020).
    136. TUEV AUSTRIA HOLDING AG 2019. OK biodegradable Soil. Available online: (accessed on 01.09.2020).