Biodegradation

Biodegradation is the breakdown of organic matter by

microorganisms, such as bacteria and fungi.[a][2] It is generally
assumed to be a natural process, which differentiates it from
composting. Composting is a human-driven process in which
biodegradation occurs under a specific set of circumstances.

The process of biodegradation is threefold: first an object

undergoes biodeterioration, which is the mechanical
weakening of its structure; then follows biofragmentation,
which is the breakdown of materials by microorganisms; and
finally assimilation, which is the incorporation of the old
Yellow slime mold growing on a bin of wet
material into new cells.
paper
In practice, almost all chemical compounds and materials are
subject to biodegradation, the key element being time. Things
like vegetables may degrade within days, while glass and some plastics take many millennia to decompose.
A standard for biodegradability used by the European Union is that greater than 90% of the original
material must be converted into CO2 , water and minerals by biological processes within 6 months.

Contents
Mechanisms
Factors affecting biodegradation rate
Plastics
Biodegradable technology
Biodegradation vs. composting
Environmental and social effects
Etymology of "biodegradable"
See also
Notes
References
Standards by ASTM International
External links

Mechanisms
The process of biodegradation can be divided into three stages: biodeterioration, biofragmentation, and
assimilation.[3] Biodeterioration is sometimes described as a surface-level degradation that modifies the
mechanical, physical and chemical properties of the material. This stage occurs when the material is
exposed to abiotic factors in the outdoor environment and allows for further degradation by weakening the
material's structure. Some abiotic factors that influence these initial changes are compression (mechanical),
light, temperature and chemicals in the environment.[3] While biodeterioration typically occurs as the first
stage of biodegradation, it can in some cases be parallel to biofragmentation.[4] Hueck,[5] however, defined
Biodeterioration as the undesirable action of living organisms on Man's materials, involving such things as
breakdown of stone facades of buildings,[6] corrosion of metals by microorganisms or merely the esthetic
changes induced on man-made structures by the growth of living organisms.[6]

Biofragmentation of a polymer is the lytic process in which bonds within a polymer are cleaved, generating
oligomers and monomers in its place.[3] The steps taken to fragment these materials also differ based on the
presence of oxygen in the system. The breakdown of materials by microorganisms when oxygen is present
is aerobic digestion, and the breakdown of materials when oxygen is not present is anaerobic digestion.[7]
The main difference between these processes is that anaerobic reactions produce methane, while aerobic
reactions do not (however, both reactions produce carbon dioxide, water, some type of residue, and a new
biomass).[8] In addition, aerobic digestion typically occurs more rapidly than anaerobic digestion, while
anaerobic digestion does a better job reducing the volume and mass of the material.[7] Due to anaerobic
digestion's ability to reduce the volume and mass of waste materials and produce a natural gas, anaerobic
digestion technology is widely used for waste management systems and as a source of local, renewable
energy.[9]

In the assimilation stage, the resulting products from biofragmentation are then integrated into microbial
cells.[3] Some of the products from fragmentation are easily transported within the cell by membrane
carriers. However, others still have to undergo biotransformation reactions to yield products that can then be
transported inside the cell. Once inside the cell, the products enter catabolic pathways that either lead to the
production of adenosine triphosphate (ATP) or elements of the cells structure.[3]

Factors affecting
biodegradation rate Aerobic biodegradation formula

In practice, almost all chemical compounds

and materials are subject to biodegradation
processes. The significance, however, is in the Anaerobic degradation formula
relative rates of such processes, such as days,
weeks, years or centuries. A number of factors
determine the rate at which this degradation of organic compounds occurs. Factors include light, water,
oxygen and temperature.[10] The degradation rate of many organic compounds is limited by their
bioavailability, which is the rate at which a substance is absorbed into a system or made available at the site
of physiological activity,[11] as compounds must be released into solution before organisms can degrade
them. The rate of biodegradation can be measured in a number of ways. Respirometry tests can be used for
aerobic microbes. First one places a solid waste sample in a container with microorganisms and soil, and
then aerates the mixture. Over the course of several days, microorganisms digest the sample bit by bit and
produce carbon dioxide – the resulting amount of CO2 serves as an indicator of degradation.
Biodegradability can also be measured by anaerobic microbes and the amount of methane or alloy that they
are able to produce.[12]

It's important to note factors that affect biodegradation rates during product testing to ensure that the results
produced are accurate and reliable. Several materials will test as being biodegradable under optimal
conditions in a lab for approval but these results may not reflect real world outcomes where factors are
more variable.[13] For example, a material may have tested as biodegrading at a high rate in the lab may not
degrade at a high rate in a landfill because landfills often lack light, water, and microbial activity that are
necessary for degradation to occur.[14] Thus, it is very important that there are standards for plastic
biodegradable products, which
have a large impact on the
environment. The development
and use of accurate standard test
methods can help ensure that all
plastics that are being produced
and commercialized will
actually biodegrade in natural
environments.[15] One test that
has been developed for this
purpose is DINV 54900.[16]

Approximated time for

compounds to biodegrade in a
marine environment[17]
Time to
Product
Biodegrade
Average estimated decomposition times of typical marine debris items.
Paper towel 2–4 weeks
Plastic items are shown in blue.
Newspaper 6 weeks

Apple core 2 months

Cardboard
2 months
box

Wax coated
3 months
milk carton

Cotton
1–5 months
gloves

Wool gloves 1 year

Plywood 1–3 years

Painted
wooden 13 years
sticks
Plastic bags 10–20 years

Tin cans 50 years

Disposable
50–100 years
diapers

Plastic bottle 100 years

Aluminium
200 years
cans

Glass bottles Undetermined

 Time-frame for common items to break down in a
terrestrial environment[14]
Vegetables 5 days – 1 month

Paper 2–5 months

Cotton T-shirt 6 months

Orange peels 6 months

Tree leaves 1 year

Wool socks 1–5 years

Plastic-coated paper milk cartons 5 years

Leather shoes 25–40 years

Nylon fabric 30–40 years

Tin cans 50–100 years

Aluminium cans 80–100 years

Glass bottles 1 million years

Styrofoam cup 500 years to forever

Plastic bags 500 years to forever

Plastics
The term Biodegradable Plastics refers to materials that maintain their mechanical strength during practical
use but break down into low-weight compounds and non-toxic byproducts after their use.[18] This
breakdown is made possible through an attack of microorganisms on the material, which is typically a non-
water-soluble polymer.[4] Such materials can be obtained through chemical synthesis, fermentation by
microorganisms, and from chemically modified natural products.[19]

Plastics biodegrade at highly variable rates. PVC-based plumbing is selected for handling sewage because
PVC resists biodegradation. Some packaging materials on the other hand are being developed that would
degrade readily upon exposure to the environment.[20] Examples of synthetic polymers that biodegrade
quickly include polycaprolactone, other polyesters and aromatic-aliphatic esters, due to their ester bonds
being susceptible to attack by water. A prominent example is poly-3-hydroxybutyrate, the renewably
derived polylactic acid. Others are the cellulose-based cellulose acetate and celluloid (cellulose nitrate).

Under low oxygen conditions plastics break down more slowly. The
breakdown process can be accelerated in specially designed compost heap.
Starch-based plastics will degrade within two to four months in a home
compost bin, while polylactic acid is largely undecomposed, requiring higher
temperatures.[21] Polycaprolactone and polycaprolactone-starch composites
decompose slower, but the starch content accelerates decomposition by leaving
behind a porous, high surface area polycaprolactone. Nevertheless, it takes
many months.[22]
Polylactic acid is an
In 2016, a bacterium named Ideonella sakaiensis was found to biodegrade
example of a plastic that
PET. In 2020, the PET degrading enzyme of the bacterium, PETase, has been
biodegrades quickly.
genetically modified and combined with MHETase to break down PET faster,
and also degrade PEF.[23][24][25] In 2021, researchers reported that a mix of microorganisms from cow
stomachs could break down three types of plastics.[26][27]

Many plastic producers have gone so far even to say that their plastics are compostable, typically listing
corn starch as an ingredient. However, these claims are questionable because the plastics industry operates
under its own definition of compostable:

"that which is capable of undergoing biological decomposition in a compost site such that
the material is not visually distinguishable and breaks down into carbon dioxide, water,
inorganic compounds and biomass at a rate consistent with known compostable
materials." (Ref: ASTM D 6002)[28]

The term "composting" is often used informally to describe the biodegradation of packaging materials.
Legal definitions exist for compostability, the process that leads to compost. Four criteria are offered by the
European Union:[29][30]

1. Chemical composition: volatile matter and heavy metals as well as fluorine should be
limited.
2. Biodegradability: the conversion of >90% of the original material into CO2, water and
minerals by biological processes within 6 months.
3. Disintegrability: at least 90% of the original mass should be decomposed into particles that
are able to pass through a 2x2 mm sieve.
4. Quality: absence of toxic substances and other substances that impede composting.

Biodegradable technology
Biodegradable technology is established technology with some applications in product packaging,
production, and medicine.[31] The chief barrier to widespread implementation is the trade-off between
biodegradability and performance. For example, lactide-based plastics are inferior packaging properties in
comparison to traditional materials.

Oxo-biodegradation is defined by CEN (the European Standards Organisation) as "degradation resulting

from oxidative and cell-mediated phenomena, either simultaneously or successively." While sometimes
described as "oxo-fragmentable," and "oxo-degradable" these terms describe only the first or oxidative
phase and should not be used for material which degrades by the process of oxo-biodegradation defined by
CEN: the correct description is "oxo-biodegradable." Oxo-biodegradable formulations accelerate the
biodegradation process but it takes considerable skill and experience to balance the ingredients within the
formulations so as to provide the product with a useful life for a set period, followed by degradation and
biodegradation.[32]

Biodegradable technology is especially utilized by the bio-medical community. Biodegradable polymers are
classified into three groups: medical, ecological, and dual application, while in terms of origin they are
divided into two groups: natural and synthetic.[18] The Clean Technology Group is exploiting the use of
supercritical carbon dioxide, which under high pressure at room temperature is a solvent that can use
biodegradable plastics to make polymer drug coatings. The polymer (meaning a material composed of
molecules with repeating structural units that form a long chain) is used to encapsulate a drug prior to
injection in the body and is based on lactic acid, a compound normally produced in the body, and is thus
able to be excreted naturally. The coating is designed for controlled release over a period of time, reducing
the number of injections required and maximizing the therapeutic benefit. Professor Steve Howdle states
that biodegradable polymers are particularly attractive for use in drug delivery, as once introduced into the
body they require no retrieval or further manipulation and are degraded into soluble, non-toxic by-products.
Different polymers degrade at different rates within the body and therefore polymer selection can be
tailored to achieve desired release rates.[33]

Other biomedical applications include the use of biodegradable, elastic shape-memory polymers.
Biodegradable implant materials can now be used for minimally invasive surgical procedures through
degradable thermoplastic polymers. These polymers are now able to change their shape with increase of
temperature, causing shape memory capabilities as well as easily degradable sutures. As a result, implants
can now fit through small incisions, doctors can easily perform complex deformations, and sutures and
other material aides can naturally biodegrade after a completed surgery.[34]

Biodegradation vs. composting

There is no universal definition for biodegradation and there are various definitions of composting, which
has led to much confusion between the terms. They are often lumped together; however, they do not have
the same meaning. Biodegradation is the naturally-occurring breakdown of materials by microorganisms
such as bacteria and fungi or other biological activity.[35] Composting is a human-driven process in which
biodegradation occurs under a specific set of circumstances.[36] The predominant difference between the
two is that one process is naturally-occurring and one is human-driven.

Biodegradable material is capable of decomposing without an oxygen source (anaerobically) into carbon
dioxide, water, and biomass, but the timeline is not very specifically defined. Similarly, compostable
material breaks down into carbon dioxide, water, and biomass; however, compostable material also breaks
down into inorganic compounds. The process for composting is more specifically defined, as it is controlled
by humans. Essentially, composting is an accelerated biodegradation process due to optimized
circumstances.[37] Additionally, the end product of composting not only returns to its previous state, but
also generates and adds beneficial microorganisms to the soil called humus. This organic matter can be used
in gardens and on farms to help grow healthier plants in the future.[38] Composting more consistently
occurs within a shorter time frame since it is a more defined process and is expedited by human
intervention. Biodegradation can occur in different time frames under different circumstances, but is meant
to occur naturally without human intervention.

Even within composting, there are different circumstances under

which this can occur. The two main types of composting are at-
home versus commercial. Both produce healthy soil to be reused -
the main difference lies in what materials are able to go into the
process.[37] At-home composting is mostly used for food scraps
and excess garden materials, such as weeds. Commercial
composting is capable of breaking down more complex plant-based
products, such as corn-based plastics and larger pieces of material,
like tree branches. Commercial composting begins with a manual
breakdown of the materials using a grinder or other machine to
initiate the process. Because at-home composting usually occurs on
a smaller scale and does not involve large machinery, these
materials would not fully decompose in at-home composting.
Furthermore, one study has compared and contrasted home and
industrial composting, concluding that there are advantages and
disadvantages to both.[40] This figure represents the different
paths of disposal for organic
waste.[39]
The following studies provide examples in which composting has been defined as a subset of
biodegradation in a scientific context. The first study, "Assessment of Biodegradability of Plastics Under
Simulated Composting Conditions in a Laboratory Test Setting," clearly examines composting as a set of
circumstances that falls under the category of degradation.[41] Additionally, this next study looked at the
biodegradation and composting effects of chemically and physically crosslinked polylactic acid.[42]
Notably discussing composting and biodegrading as two distinct terms. The third and final study reviews
European standardization of biodegradable and compostable material in the packaging industry, again using
the terms separately.[43]

The distinction between these terms is crucial because waste management confusion leads to improper
disposal of materials by people on a daily basis. Biodegradation technology has led to massive
improvements in how we dispose of waste; there now exist trash, recycling, and compost bins in order to
optimize the disposal process. However, if these waste streams are commonly and frequently confused,
then the disposal process is not at all optimized.[44] Biodegradable and compostable materials have been
developed to ensure more of human waste is able to breakdown and return to its previous state, or in the
case of composting even add nutrients to the ground.[45] When a compostable product is thrown out as
opposed to composted and sent to a landfill, these inventions and efforts are wasted. Therefore, it is
important for citizens to understand the difference between these terms so that materials can be disposed of
properly and efficiently.

Environmental and social effects

Plastic pollution from illegal dumping poses health risks to wildlife. Animals often mistake plastics for food,
resulting in intestinal entanglement. Slow-degrading chemicals, like polychlorinated biphenyls (PCBs),
nonylphenol (NP), and pesticides also found in plastics, can release into environments and subsequently
also be ingested by wildlife.[46]

These chemicals also play a role in human health, as consumption of tainted food (in processes called
biomagnification and bioaccumulation) has been linked to issues such as cancers,[47] neurological
dysfunction,[48] and hormonal changes. A well-known example of biomagnification impacting health in
recent times is the increased exposure to dangerously high levels of mercury in fish, which can affect sex
hormones in humans.[49]

In efforts to remediate the damages done by slow-degrading plastics, detergents, metals, and other
pollutants created by humans, economic costs have become a concern. Marine litter in particular is notably
difficult to quantify and review.[50] Researchers at the World Trade Institute estimate that cleanup initiatives'
cost (specifically in ocean ecosystems) has hit close to thirteen billion dollars a year.[51] The main concern
stems from marine environments, with the biggest cleanup efforts centering around garbage patches in the
ocean. In 2017, a garbage patch the size of Mexico was found in the Pacific Ocean. It is estimated to be
upwards of a million square miles in size. While the patch contains more obvious examples of litter (plastic
bottles, cans, and bags), tiny microplastics are nearly impossible to clean up.[52] National Geographic
reports that even more non-biodegradable materials are finding their way into vulnerable environments -
nearly thirty-eight million pieces a year.[53]

Materials that have not degraded can also serve as shelter for invasive species, such as tube worms and
barnacles. When the ecosystem changes in response to the invasive species, resident species and the natural
balance of resources, genetic diversity, and species richness is altered.[54] These factors may support local
economies in way of hunting and aquaculture, which suffer in response to the change.[55] Similarly, coastal
communities which rely heavily on ecotourism lose revenue thanks to a buildup of pollution, as their
beaches or shores are no longer desirable to travelers. The World Trade Institute also notes that the
communities who often feel most of the effects of poor biodegradation are poorer countries without the
means to pay for their cleanup.[51] In a positive feedback loop effect, they in turn have trouble controlling
their own pollution sources.[56]

Etymology of "biodegradable"
The first known use of biodegradable in a biological context was in 1959 when it was employed to
describe the breakdown of material into innocuous components by microorganisms.[57] Now
biodegradable is commonly associated with environmentally friendly products that are part of the earth's
innate cycles like the carbon cycle and capable of decomposing back into natural elements.

See also
Ecology portal
Environment
portal

Anaerobic digestion
Assimilation (biology)
Bioaccumulation
Biodegradability prediction
Biodegradable electronics
Biodegradable polythene film
Biodegradation (journal)
Biomagnification
Bioplastic – biodegradable, bio-based plastics
Bioremediation
Decomposition – reduction of the body of a formerly living organism into simpler forms of
matter
Landfill gas monitoring
List of environment topics
Microbial biodegradation
Photodegradation

Notes
a. The IUPAC defines biodegradation as "degradation caused by enzymatic process resulting
from the action of cells" and notes that the definition is "modified to exclude abiotic
enzymatic processes."[1]

References
1. Vert M, Doi Y, Hellwich KH, Hess M, Hodge P, Kubisa P, Rinaudo M, Schué F (2012).
"Terminology for biorelated polymers and applications (IUPAC Recommendations 2012)".
Pure and Applied Chemistry. 84 (2): 377–410. doi:10.1351/PAC-REC-10-12-04 (https://doi.o
rg/10.1351%2FPAC-REC-10-12-04). S2CID 98107080 (https://api.semanticscholar.org/Corp
usID:98107080).
 2. Focht DD. "Biodegradation". AccessScience. doi:10.1036/1097-8542.422025 (https://doi.or
g/10.1036%2F1097-8542.422025).
3. Lucas N, Bienaime C, Belloy C, Queneudec M, Silvestre F, Nava-Saucedo JE (September
2008). "Polymer biodegradation: mechanisms and estimation techniques". Chemosphere.
73 (4): 429–42. Bibcode:2008Chmsp..73..429L (https://ui.adsabs.harvard.edu/abs/2008Chm
sp..73..429L). doi:10.1016/j.chemosphere.2008.06.064 (https://doi.org/10.1016%2Fj.chemos
phere.2008.06.064). PMID 18723204 (https://pubmed.ncbi.nlm.nih.gov/18723204).
4. Muller R (2005). "Biodegradability of Polymers: Regulations and Methods for Testing" (http
s://application.wiley-vch.de/books/biopoly/pdf_v10/vol10_19.pdf) (PDF). In Steinbüchel A
(ed.). Biopolymers. Wiley-VCH. doi:10.1002/3527600035.bpola012 (https://doi.org/10.100
2%2F3527600035.bpola012). ISBN 978-3-527-30290-1.
5. Hueck, Hans (January 1966). "The biodeterioration of materials as part of hylobiology".
Material und Organismen. 1: 5–34 – via ISSN 00255270.
6. Allsopp, Dennis (2004). Introduction to Biodeterioration. Cambridge: Cambridge University
Press. ISBN 9780511617065.
7. "Aerobic and Anaerobic Biodegradation" (http://www.polimernet.com/Docs/Aerobic%20-%20
Anaerobic%20Biodegredation%20en.pdf) (PDF). Fundamentals of Aerobic & Anaerobic
Biodegradation Process. Polimernet Plastik San. Tic. Ltd. Şti. Archived (https://web.archive.o
rg/web/20110419204604/http://polimernet.com/Docs/Aerobic%20-%20Anaerobic%20Biode
gredation%20en.pdf) (PDF) from the original on 2011-04-19.
8. Van der Zee M (2011). "Analytical Methods for Monitoring Biodegradation Processes of
Environmentally Degradable Polymers" (http://edepot.wur.nl/193543).
9. Klinkner BA (2014). "Anaerobic Digestion as a Renewable Energy Source and Waste
Management Technology: What Must be Done for this Technology to Realize Success in the
United States?" (https://scholarship.law.umassd.edu/cgi/viewcontent.cgi?article=1027&cont
ext=umlr). University of Massachusetts Law Review. 9: 68–96.
10. Haider T, Völker C, Kramm J, Landfester K, Wurm FR (July 2018). "Plastics of the future?
The impact of biodegradable polymers on the environment and on society" (https://doi.org/1
0.1002%2Fanie.201805766). Angewandte Chemie International Edition in English. 58 (1):
50–62. doi:10.1002/anie.201805766 (https://doi.org/10.1002%2Fanie.201805766).
PMID 29972726 (https://pubmed.ncbi.nlm.nih.gov/29972726).
11. "Definition of BIOAVAILABILITY" (https://www.merriam-webster.com/dictionary/bioavailabilit
y). www.merriam-webster.com. Retrieved 2018-09-19.
12. Jessop A (2015-09-16). "How is biodegradability measured?" (https://commercialwaste.trad
e/how-is-biodegradability-measured/). Commercial Waste. Retrieved 2018-09-19.
13. Adamcova D, Radziemska M, Fronczyk J, Zloch J, Vaverkova MD (2017). "Research of the
biodegradability of degradable/biodegradable plastic material in various types of
environments" (https://doi.org/10.22630%2FPNIKS.2017.26.1.01). Przegląd Naukowy.
Inżynieria i Kształtowanie Środowiska. 26: 3–14. doi:10.22630/PNIKS.2017.26.1.01 (https://
doi.org/10.22630%2FPNIKS.2017.26.1.01).
14. "Measuring biodegradability" (https://www.sciencelearn.org.nz/resources/1543-measuring-bi
odegradability). Science Learning Hub. Retrieved 2018-09-19.
15. Scott G, Gilead D, eds. (1995). Degradable Polymers. Netherlands: Dordrecht Springer.
doi:10.1007/978-94-011-0571-2 (https://doi.org/10.1007%2F978-94-011-0571-2). ISBN 978-
94-010-4253-6.
16. Witt U, Yamamoto M, Seeliger U, Müller RJ, Warzelhan V (May 1999). "Biodegradable
Polymeric Materials-Not the Origin but the Chemical Structure Determines Biodegradability".
Angewandte Chemie. 38 (10): 1438–1442. doi:10.1002/(sici)1521-
3773(19990517)38:10<1438::aid-anie1438>3.0.co;2-u (https://doi.org/10.1002%2F%28sic
i%291521-3773%2819990517%2938%3A10%3C1438%3A%3Aaid-anie1438%3E3.0.co%
3B2-u). PMID 29711570 (https://pubmed.ncbi.nlm.nih.gov/29711570).
17. "Marine Debris Biodegradation Time Line" (http://cmore.soest.hawaii.edu/cruises/super/biod
egradation.htm) Archived (https://web.archive.org/web/20111105113852/http://cmore.soest.h
awaii.edu/cruises/super/biodegradation.htm) 2011-11-05 at the Wayback Machine. C-
MORE, citing Mote Marine Laboratory, 1993.
18. Ikada Y, Tsuji H (February 2000). "Biodegradable polyesters for medical and ecological
applications" (http://web.mit.edu/course/10/10.569/www/ikadaPEreview.pdf) (PDF).
Macromolecular Rapid Communications. 21 (3): 117–132. doi:10.1002/(sici)1521-
3927(20000201)21:3<117::aid-marc117>3.0.co;2-x (https://doi.org/10.1002%2F%28sici%29
1521-3927%2820000201%2921%3A3%3C117%3A%3Aaid-marc117%3E3.0.co%3B2-x).
19. Flieger M, Kantorová M, Prell A, Rezanka T, Votruba J (January 2003). "Biodegradable
plastics from renewable sources". Folia Microbiologica. 48 (1): 27–44.
doi:10.1007/bf02931273 (https://doi.org/10.1007%2Fbf02931273). PMID 12744074 (https://p
ubmed.ncbi.nlm.nih.gov/12744074). S2CID 32800851 (https://api.semanticscholar.org/Corp
usID:32800851).
20. Kyrikou I, Briassoulis D (12 Apr 2007). "Biodegradation of Agricultural Plastic Films: A
Critical Review". Journal of Polymers and the Environment. 15 (2): 125–150.
doi:10.1007/s10924-007-0053-8 (https://doi.org/10.1007%2Fs10924-007-0053-8).
S2CID 195331133 (https://api.semanticscholar.org/CorpusID:195331133).
21. "Section 6: Biodegradability of Packaging Waste" (http://www3.imperial.ac.uk/pls/portallive/d
ocs/1/33773706.PDF) (PDF). Www3.imperial.ac.uk. Archived (https://web.archive.org/web/2
0130602155241/http://www3.imperial.ac.uk/pls/portallive/docs/1/33773706.PDF) (PDF)
from the original on 2013-06-02. Retrieved 2014-03-02.
22. Wu C (January 2003). "Physical properties and biodegradability of maleated-
polycaprolactone/starch composite" (http://www.kyu.edu.tw/93/epaperv6/93-129.pdf) (PDF).
Polymer Degradation and Stability. 80 (1): 127–134. CiteSeerX 10.1.1.453.4220 (https://cite
seerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.453.4220). doi:10.1016/S0141-
3910(02)00393-2 (https://doi.org/10.1016%2FS0141-3910%2802%2900393-2).
23. Carrington, Damian (28 September 2020). "New super-enzyme eats plastic bottles six times
faster" (https://www.theguardian.com/environment/2020/sep/28/new-super-enzyme-eats-pla
stic-bottles-six-times-faster). The Guardian. Retrieved 12 October 2020.
24. "Plastic-eating enzyme 'cocktail' heralds new hope for plastic waste" (https://phys.org/news/
2020-09-plastic-eating-enzyme-cocktail-heralds-plastic.html). phys.org. Retrieved
12 October 2020.
25. Knott, Brandon C.; Erickson, Erika; Allen, Mark D.; Gado, Japheth E.; Graham, Rosie;
Kearns, Fiona L.; Pardo, Isabel; Topuzlu, Ece; Anderson, Jared J.; Austin, Harry P.;
Dominick, Graham; Johnson, Christopher W.; Rorrer, Nicholas A.; Szostkiewicz, Caralyn J.;
Copié, Valérie; Payne, Christina M.; Woodcock, H. Lee; Donohoe, Bryon S.; Beckham,
Gregg T.; McGeehan, John E. (24 September 2020). "Characterization and engineering of a
two-enzyme system for plastics depolymerization" (https://www.ncbi.nlm.nih.gov/pmc/article
s/PMC7568301). Proceedings of the National Academy of Sciences. 117 (41): 25476–
25485. doi:10.1073/pnas.2006753117 (https://doi.org/10.1073%2Fpnas.2006753117).
ISSN 0027-8424 (https://www.worldcat.org/issn/0027-8424). PMC 7568301 (https://www.ncb
i.nlm.nih.gov/pmc/articles/PMC7568301). PMID 32989159 (https://pubmed.ncbi.nlm.nih.gov/
32989159).
26. Spary, Sara. "Cows' stomachs can break down plastic, study finds" (https://edition.cnn.com/2
021/07/02/world/cows-plastic-scli-intl-scn/index.html). CNN. Retrieved 14 August 2021.
27. Quartinello, Felice; Kremser, Klemens; Schoen, Herta; Tesei, Donatella; Ploszczanski, Leon;
Nagler, Magdalena; Podmirseg, Sabine M.; Insam, Heribert; Piñar, Guadalupe; Sterflingler,
Katja; Ribitsch, Doris; Guebitz, Georg M. (2021). "Together Is Better: The Rumen Microbial
Community as Biological Toolbox for Degradation of Synthetic Polyesters" (https://doi.org/1
0.3389%2Ffbioe.2021.684459). Frontiers in Bioengineering and Biotechnology. 9.
doi:10.3389/fbioe.2021.684459 (https://doi.org/10.3389%2Ffbioe.2021.684459). ISSN 2296-
4185 (https://www.worldcat.org/issn/2296-4185).
28. "Compostable" (http://www.compostable.info/compostable.htm). Compostable.info.
Retrieved 2014-03-02.
29. "Requirements of the EN 13432 standard" (https://docs.european-bioplastics.org/publication
s/bp/EUBP_BP_En_13432.pdf) (PDF). European Bioplastics. Brussels, Belgium. April
2015. Archived (https://web.archive.org/web/20180924190657/https://docs.european-bioplas
tics.org/publications/bp/EUBP_BP_En_13432.pdf) (PDF) from the original on 2018-09-24.
Retrieved July 22, 2017.
30. Breulmann M, Künkel A, Philipp S, Reimer V, Siegenthaler KO, Skupin G, Yamamoto M
(2012). "Polymers, Biodegradable". Ullmann's Encyclopedia of Industrial Chemistry.
Weinheim: Wiley-VCH. doi:10.1002/14356007.n21_n01 (https://doi.org/10.1002%2F143560
07.n21_n01). ISBN 978-3527306732.
31. Gross RA, Kalra B (August 2002). "Biodegradable polymers for the environment" (https://zen
odo.org/record/1231185). Science. 297 (5582): 803–7. Bibcode:2002Sci...297..803G (https://
ui.adsabs.harvard.edu/abs/2002Sci...297..803G). doi:10.1126/science.297.5582.803 (https://
doi.org/10.1126%2Fscience.297.5582.803). PMID 12161646 (https://pubmed.ncbi.nlm.nih.g
ov/12161646).
32. Agamuthu P, Faizura PN (April 2005). "Biodegradability of degradable plastic waste". Waste
Management & Research. 23 (2): 95–100. doi:10.1177/0734242X05051045 (https://doi.org/1
0.1177%2F0734242X05051045). PMID 15864950 (https://pubmed.ncbi.nlm.nih.gov/158649
50). S2CID 2552973 (https://api.semanticscholar.org/CorpusID:2552973).
33. The University of Nottingham (September 13, 2007). "Using Green Chemistry to Deliver
Cutting Edge Drugs" (https://www.sciencedaily.com/releases/2007/09/070913132945.htm).
Science Daily.
34. Lendlein A, Langer R (May 2002). "Biodegradable, elastic shape-memory polymers for
potential biomedical applications". Science. 296 (5573): 1673–6.
Bibcode:2002Sci...296.1673L (https://ui.adsabs.harvard.edu/abs/2002Sci...296.1673L).
doi:10.1126/science.1066102 (https://doi.org/10.1126%2Fscience.1066102).
PMID 11976407 (https://pubmed.ncbi.nlm.nih.gov/11976407). S2CID 21801034 (https://api.s
emanticscholar.org/CorpusID:21801034).
35. Gómez EF, Michel FC (December 2013). "Biodegradability of conventional and bio-based
plastics and natural fiber composites during composting, anaerobic digestion and long-term
soil incubation". Polymer Degradation and Stability. 98 (12): 2583–2591.
doi:10.1016/j.polymdegradstab.2013.09.018 (https://doi.org/10.1016%2Fj.polymdegradstab.
2013.09.018).
36. "Biodegradable Products Institute - Composting" (https://bpiworld.org/Composting).
bpiworld.org. Retrieved 2018-09-24.
37. Magdoff F (November 1993). "Building Soils for Better Crops". Soil Science. 156 (5): 371.
Bibcode:1993SoilS.156..371M (https://ui.adsabs.harvard.edu/abs/1993SoilS.156..371M).
doi:10.1097/00010694-199311000-00014 (https://doi.org/10.1097%2F00010694-19931100
0-00014).
38. Morris S, Martin JP. "Humus" (https://www.accessscience.com/content/325510).
AccessScience. doi:10.1036/1097-8542.325510 (https://doi.org/10.1036%2F1097-8542.325
510). Retrieved 2018-09-24.
39. Kranert M, Behnsen A, Schultheis A, Steinbach D (2002). "Composting in the Framework of
the EU Landfill Directive". Microbiology of Composting. Springer Berlin Heidelberg.
pp. 473–486. doi:10.1007/978-3-662-08724-4_39 (https://doi.org/10.1007%2F978-3-662-08
724-4_39). ISBN 9783642087059.
40. Martínez-Blanco J, Colón J, Gabarrell X, Font X, Sánchez A, Artola A, Rieradevall J (June
2010). "The use of life cycle assessment for the comparison of biowaste composting at
home and full scale" (http://ddd.uab.cat/record/163720). Waste Management (Submitted
manuscript). 30 (6): 983–94. doi:10.1016/j.wasman.2010.02.023 (https://doi.org/10.1016%2F
j.wasman.2010.02.023). PMID 20211555 (https://pubmed.ncbi.nlm.nih.gov/20211555).
41. Starnecker A, Menner M (1996-01-01). "Assessment of biodegradability of plastics under
simulated composting conditions in a laboratory test system". International Biodeterioration
& Biodegradation. 37 (1–2): 85–92. doi:10.1016/0964-8305(95)00089-5 (https://doi.org/10.1
016%2F0964-8305%2895%2900089-5).
42. Żenkiewicz M, Malinowski R, Rytlewski P, Richert A, Sikorska W, Krasowska K (2012-02-
01). "Some composting and biodegradation effects of physically or chemically crosslinked
poly(lactic acid)" (https://doi.org/10.1016%2Fj.polymertesting.2011.09.012). Polymer
Testing. 31 (1): 83–92. doi:10.1016/j.polymertesting.2011.09.012 (https://doi.org/10.1016%2
Fj.polymertesting.2011.09.012).
43. Avella M, Bonadies E, Martuscelli E, Rimedio R (2001-01-01). "European current
standardization for plastic packaging recoverable through composting and biodegradation".
Polymer Testing. 20 (5): 517–521. doi:10.1016/S0142-9418(00)00068-4 (https://doi.org/10.1
016%2FS0142-9418%2800%2900068-4).
44. Akullian A, Karp C, Austin K, Durbin D (2006). "Plastic Bag Externalities and Policy in
Rhode Island" (http://seattlebagtax.org/referencedpdfs/en-akullianetal.pdf) (PDF). Brown
Policy Review.
45. Song JH, Murphy RJ, Narayan R, Davies GB (July 2009). "Biodegradable and compostable
alternatives to conventional plastics" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC287301
8). Philosophical Transactions of the Royal Society of London. Series B, Biological
Sciences. 364 (1526): 2127–39. doi:10.1098/rstb.2008.0289 (https://doi.org/10.1098%2Frst
b.2008.0289). PMC 2873018 (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2873018).
PMID 19528060 (https://pubmed.ncbi.nlm.nih.gov/19528060).
46. Webb H, Arnott J, Crawford R, Ivanova E, Webb HK, Arnott J, Crawford RJ, Ivanova EP
(2012-12-28). "Plastic Degradation and Its Environmental Implications with Special
Reference to Poly(ethylene terephthalate)" (https://doi.org/10.3390%2Fpolym5010001).
Polymers. 5 (1): 1–18. doi:10.3390/polym5010001 (https://doi.org/10.3390%2Fpolym501000
1).
47. Kelly BC, Ikonomou MG, Blair JD, Morin AE, Gobas FA (July 2007). "Food web-specific
biomagnification of persistent organic pollutants". Science. 317 (5835): 236–9.
Bibcode:2007Sci...317..236K (https://ui.adsabs.harvard.edu/abs/2007Sci...317..236K).
doi:10.1126/science.1138275 (https://doi.org/10.1126%2Fscience.1138275).
PMID 17626882 (https://pubmed.ncbi.nlm.nih.gov/17626882). S2CID 52835862 (https://api.s
emanticscholar.org/CorpusID:52835862).
48. Passos CJ, Mergler D (2008). "Human mercury exposure and adverse health effects in the
Amazon: a review" (https://doi.org/10.1590%2Fs0102-311x2008001600004). Cadernos de
Saude Publica. 24 Suppl 4: s503–20. doi:10.1590/s0102-311x2008001600004 (https://doi.o
rg/10.1590%2Fs0102-311x2008001600004). PMID 18797727 (https://pubmed.ncbi.nlm.nih.
gov/18797727).
49. Rana SV (July 2014). "Perspectives in endocrine toxicity of heavy metals--a review".
Biological Trace Element Research. 160 (1): 1–14. doi:10.1007/s12011-014-0023-7 (https://
doi.org/10.1007%2Fs12011-014-0023-7). PMID 24898714 (https://pubmed.ncbi.nlm.nih.gov/
24898714). S2CID 18562345 (https://api.semanticscholar.org/CorpusID:18562345).
50. Newman S, Watkins E, Farmer A, Brink Pt, Schweitzer J (2015). "The Economics of Marine
Litter". Marine Anthropogenic Litter. Springer International Publishing. pp. 367–394.
doi:10.1007/978-3-319-16510-3_14 (https://doi.org/10.1007%2F978-3-319-16510-3_14).
ISBN 978-3-319-16509-7.
51. Matsangou E (2 July 2018). "Counting the cost of plastic pollution" (https://www.worldfinanc
e.com/markets/counting-the-cost-of-plastic-pollution). World Finance. Retrieved
17 September 2018.
52. Rochman CM, Cook AM, Koelmans AA (July 2016). "Plastic debris and policy: Using current
scientific understanding to invoke positive change" (https://doi.org/10.1002%2Fetc.3408).
Environmental Toxicology and Chemistry. 35 (7): 1617–26. doi:10.1002/etc.3408 (https://doi.
org/10.1002%2Fetc.3408). PMID 27331654 (https://pubmed.ncbi.nlm.nih.gov/27331654).
53. Montanari S (2017-07-25). "Plastic Garbage Patch Bigger Than Mexico Found in Pacific" (ht
tps://news.nationalgeographic.com/2017/07/ocean-plastic-patch-south-pacific-spd/).
National Geographic. Retrieved 2018-09-17.
54. Gregory MR (July 2009). "Environmental implications of plastic debris in marine settings--
entanglement, ingestion, smothering, hangers-on, hitch-hiking and alien invasions" (https://w
ww.ncbi.nlm.nih.gov/pmc/articles/PMC2873013). Philosophical Transactions of the Royal
Society of London. Series B, Biological Sciences. 364 (1526): 2013–25.
doi:10.1098/rstb.2008.0265 (https://doi.org/10.1098%2Frstb.2008.0265). PMC 2873013 (http
s://www.ncbi.nlm.nih.gov/pmc/articles/PMC2873013). PMID 19528053 (https://pubmed.ncbi.
nlm.nih.gov/19528053).
55. Villarrubia-Gómez P, Cornell SE, Fabres J (2018-10-01). "Marine plastic pollution as a
planetary boundary threat – The drifting piece in the sustainability puzzle" (https://doi.org/10.
1016%2Fj.marpol.2017.11.035). Marine Policy. 96: 213–220.
doi:10.1016/j.marpol.2017.11.035 (https://doi.org/10.1016%2Fj.marpol.2017.11.035).
56. Hajat A, Hsia C, O'Neill MS (December 2015). "Socioeconomic Disparities and Air Pollution
Exposure: a Global Review" (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4626327).
Current Environmental Health Reports. 2 (4): 440–50. doi:10.1007/s40572-015-0069-5 (http
s://doi.org/10.1007%2Fs40572-015-0069-5). PMC 4626327 (https://www.ncbi.nlm.nih.gov/p
mc/articles/PMC4626327). PMID 26381684 (https://pubmed.ncbi.nlm.nih.gov/26381684).
57. "Definition of BIODEGRADABLE" (https://www.merriam-webster.com/dictionary/biodegrada
ble). www.merriam-webster.com. Retrieved 2018-09-24.

Standards by ASTM International

D5210- Standard Test Method for Determining the Anaerobic Biodegradation of Plastic
Materials in the Presence of Municipal Sewage Sludge
D5526- Standard Test Method for Determining Anaerobic Biodegradation of Plastic
Materials Under Accelerated Landfill Conditions
D5338- Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials
Under Controlled Composting Conditions, Incorporating Thermophilic Temperatures
D5511- Standard Test Method for Determining Anaerobic Biodegradation of Plastic
Materials Under High-Solids Anaerobic-Digestion Conditions
D5864- Standard Test Method for Determining Aerobic Aquatic Biodegradation of Lubricants
or Their Components
 D5988- Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in
Soil
D6139- Standard Test Method for Determining the Aerobic Aquatic Biodegradation of
Lubricants or Their Components Using the Gledhill Shake Flask
D6006- Standard Guide for Assessing Biodegradability of Hydraulic Fluids
D6340- Standard Test Methods for Determining Aerobic Biodegradation of Radiolabeled
Plastic Materials in an Aqueous or Compost Environment
D6691- Standard Test Method for Determining Aerobic Biodegradation of Plastic Materials in
the Marine Environment by a Defined Microbial Consortium or Natural Sea Water Inoculum
D6731-Standard Test Method for Determining the Aerobic, Aquatic Biodegradability of
Lubricants or Lubricant Components in a Closed Respirometer
D6954- Standard Guide for Exposing and Testing Plastics that Degrade in the Environment
by a Combination of Oxidation and Biodegradation
D7044- Standard Specification for Biodegradable Fire Resistant Hydraulic Fluids
D7373-Standard Test Method for Predicting Biodegradability of Lubricants Using a Bio-
kinetic Model
D7475- Standard Test Method for Determining the Aerobic Degradation and Anaerobic
Biodegradation of Plastic Materials under Accelerated Bioreactor Landfill Conditions
D7665- Standard Guide for Evaluation of Biodegradable Heat Transfer Fluids

External links
European Bioplastics Association (http://www.european-bioplastics.org/)
The Science of Biodegradable Plastics: The Reality Behind Biodegradable Plastic
Packaging Material (https://web.archive.org/web/20130723014926/http://www.fpintl.com/res
ources/wp_biodegradable_plastics.htm)
Biodegradable Plastic Definition (http://www.biosphereplastic.com/uncategorized/what-is-bi
odegradation/)

Retrieved from "https://en.wikipedia.org/w/index.php?title=Biodegradation&oldid=1132945962"

This page was last edited on 11 January 2023, at 12:28 (UTC).

Text is available under the Creative Commons Attribution-ShareAlike License 3.0; additional terms may apply. By
using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the
Wikimedia Foundation, Inc., a non-profit organization.