Volume 3 • Issue 10 • 1000164
J Bioremed Biodeg
ISSN: 2155-6199 JBRBD, an open access journal
Research Article Open Access
Sangale et al., J Bioremed Biodeg 2012, 3:10
http://dx.doi.org/10.4172/2155-6199.1000164
Review Article Open Access
Bioremediation & Biodegradation
Keywords: Biodegradation, Polythene, Microbes, Waste,
Biodegraded products, Toxicity
Introduction
e contamination of soil due to dispersal of industrial and urban
wastes generated by the human activities is of great environmental
concern [1]. Various plants possess the capacity to convert the
toxic compounds into non-toxic forms and the process is known
as phytoremediation. e concept of cleaning contaminated
environment using plants is about 300 years old [2]. One of the major
environmental threat is the slow/least rate of degradation or non-
biodegradability of the organic materials under natural condition, e.g.
plastics. e plastics of various forms such as nylon, polycarbonate,
polyethylene-terephthalate, polyethylene, polypropylene, polystyrene,
polytetraflouroethylene, polyurethane, polyvinyl chloride are being
continuously used in our day-to-day life [3]. Among the synthetic
plastics waste produced, polythene shares about 64% [4]. As per
the reports the most commonly used non-degradable solid waste is
polythene which is a linear hydrocarbon polymers consisting of long
chains of the ethylene monomers (C
2
H
4
). e general formula of
polyethylene is C
n
H
2n
, where ‘n’ is the number of carbon atoms [5].
Polythene is made from the cheap petrochemical stocks extracted
from oil or gas through efficient catalytic polymerization of ethylene
monomers [6]. Polythene finds a wide range of applications in human’s
daily use because of its easy processing for various products used
for carrying food articles, for packaging textiles, for manufacturing
laboratory instruments and automotive components [5]. Various
polymers such as lignin and paraffins were reported to be degraded by
various microorganisms [6,7]. Jen-hou and Schwartz [8] carried out
the comparative degradation study of paraffins and polythene for the
first time and recorded utilization of polythene in terms of the growth
of various bacteria on these alkenes. ey concluded that microbes
can degrade only low molecular weight polythene (MW up to 4800).
Nineteen years later, degradation of high density polythene (HDPE)
film (Mw 93000) was performed and it was documented that the
main degraded component contained in HDPE film is the short-chain
oligomer [9]. ere is no such structural similarity between polythene
and lignin except to have carbon-carbon bonding which is being
broken by these microbes and using the polymers as a carbon source.
In the literature, various reviews had been written on biodegradation
of the plastic [10-18]. Only a few review [19,20] deals with polythene
but a comprehensive review on the polythene is lacking, so we tried to
highlight the glimpses of the polythene biodegradation. We also tried
to discuss, how to encounter the polythene pollution in future.
Status of Polythene Pollution
e use of plastic, especially polythene is growing day by day. Every
year 25 million tons of synthetic plastics are being accumulated in the
sea coasts and terrestrial environment [4-21]. Polythene constitutes
64% of the total synthetic plastic as it is being used in huge quantity
for the manufacture of bottles, carry bags, disposable articles, garbage
containers, margarine tubs, milk jugs, and water pipes [4]. Similarly,
in the marine environment alone, out of total marine waste, plastic
shares about 60-80% by mass [10]. All the polythene waste along with
other plastic wastes generated by the human activity finally enters into
marine water through rivers, canals/channels and municipal drainages.
erefore, the beaches were reported to be the excellent depository sites
for the polythene (plastic) wastes. At dumping sites, polythene waste
degraded with both chemical and mechanical weathering but it takes
long time for mineralization and may remain in the microscopic form
for long time [22]. Annually 500 billion to 1 trillion polythene bags
are being used routinely all over the world. Polythene is strong and
highly durable and takes up to 1000 years for natural degradation in the
environment. Furthermore, plastic degrades by sunlight into smaller
toxic parts contaminating soil and water where they can be accidentally
ingested by animals and thereby enter the food chain especially in the
marine biota [23]. To the marine life polythene waste is recognized as a
major threat. Sometimes, it could cause intestinal blockage in the fishes,
birds and marine mammals [23-25]. As per report [26] due to plastic
pollution in the marine environment minimum 267 species are being
affected which includes all mammals, sea turtles (86%) and seabirds
(44%). e death of terrestrial animals such as cow was reported due
to consumption of polythene carry bags [27]. e polythene leads to
*Corresponding author: Avinash B Ade, Department of Botany, University of
Pune, Maharashtra, India, Tel: 91-020-25601439; Fax: +91-020-25690498; E-mail:
avinashade@unipune.ac.in
Received July 07, 2012; Accepted August 28, 2012; Published August 30, 2012
Citation: Sangale MK, Shahnawaz M, Ade AB (2012) A Review on Biodegradation
of Polythene: The Microbial Approach. J Bioremed Biodeg 3:164. doi:10.4172/2155-
6199.1000164
Copyright: © 2012 Sangale MK, et al. This is an open-a ccess article distributed
under the terms of the Creative Commons Attribution License, which permits
unrestricted use, distribution, and reproduction in any medium, provided the
original author and source are credited.
A Review on Biodegradation of Polythene: The Microbial Approach
Manisha K Sangale, Mohd Shahnawaz and Avinash B Ade*
Department of Botany, University of Pune, Maharashtra, India
Abstract
The use of polythene is increasing day by day and its degradation is becoming a great challenge. Annually
about 500 billion to 1 trillion polythene carry bags are being consumed around the globe. Polythene is durable and
needs up to 1000 years for natural degradation in the environment. In the present review, an attempt has been
made to pool all the available literature on the biodegradation of polythene under the following objectives: (1) to
highlight the level of polythene pollution; (2) to enlist the cost effective methods; (3) to pool the source of polythene
degrading microbes; (4) to brief the mechanism of polythene degradation; (5) to highlight the methods used for the
biodegradation of the polythene; (6) to discuss the assessment of polythene degradation by efficient microbes; (7)
to enlist the products of polythene under degradation process; (8) to test the toxicity level of the products of the
degraded polythene, and (9) to discuss the future aspects of polythene degradation.