Hey folks, This presentation is based on a research carried out by Cristabel Ndahebwa, Huxley Makonde, Gabriel Magoma and Mabel Imbuga of Department of Pure & Applied Sciences, Technical University of Mombasa, Mombasa, Kenya, 3 Jomo Kenyatta University of Agriculture and Technology, Nairobi, Kenya. so for further information refer https://doi.org/10.1371/journal.pone.0198446

1. BIODEGRADABILITY OF
POLYETHYLENE BY BACTERIA
AND FUNGI FROM DANDORA
DUMPSITE NAIROBI, KENYA
110th October, 2019
Presented by
T.A Geethanjali
M.Sc. Bioinformatics Part - II
Guru Nanak Khalsa College
Authors:
Cristabel Ndahebwa
Huxley Makonde
Gabriel Magoma
Mabel Imbuga

2. 2
CONTENTS
Materials & method
Introduction
Result
Conclusion
Objective Future prospects
Reference

3.  Our study is aimed at identifying and isolating bacteria and
fungi with the capacity to degrade low density polyethylene
(LPDE).
OUR OBJECTIVE
3

4. Approximately 140 million tons of plastics are produced every year and high
amounts find themselves in the ecosystem as industrial waste products.
Commonly used plastics have been categorized as polyethylene (LDPE,
MDPE, HDPE and LLDPE), polypropylene (PP), polystyrene (PS) and
polyvinyl chloride (PVC).
Biodegradation can be defined as the decomposition of substances through
microbial activity. This is a complex process which involves several steps.
Microorganisms secrete enzymes and free radicals able to cleave polymer
into oligomers, dimers and monomer.
Evidence of biodegradation was based on weight loss, FT-IR and GC-MS
outcomes which confirmed that microbes are capable of degrading LDPE.
4
INTRODUCTION

5. 5
MATERIALS & METHOD
Sample collection and preparation of medium for
LPDE degrading medium
Preparation of artificial media and incubation
Determination of LPDE degrading potential of the
bacterial isolates
Isolation of LPDE degrading microorganisms
Identification of isolates

6. 6
RESULT
 Weightloss of the polyethylene sheet : Mean weight changes were computed
and used to compare the effectiveness biodegradation between fungi and bacteria
as well as between the two sets of polyethylene sheets (30 and 40 microns
 FT-IR (Fourier Transform Infra-Red) outcomes: Spectral figures indicating
formation of new functional groups as a result of new peaks on the polythene
sheets and the control (incubated without inoculum) sheets were superimposed
 GC-MS results: The gas chromatogram output from the sample of Aspergillus
oryzae (MG779508) indicated the compounds and their retention times
 Morphological characterization: A total of 26 fungal isolates were isolated.
Among these 20 were macroscopically and microscopically profiled to belong to
the genus Aspergillus while six were profiled as belonging to the genus Penicillium.
 Identification of bacterial and fungal isolate: The similarity of the sequences
obtained against known deposited 18S rRNA and 16S rRNA sequences from
closely related fungi and bacteria respectively was tested with BLASTN 2.2.1

7. 7
CONCLUSION
 The present work indicates that naturally
growing soil microbes like bacteria and fungi
show great efficacy in degrading polyethylene.
 However both fungi and bacteria showed
capacity to degrade virgin polyethylene under
laboratory conditions. Fungi of the genus
Aspergillus and bacteria of the genus Bacillus
had the highest capacity of degradation
compared to the other genera in this study.

8. 8
FUTURE PROSPECTS
 This species of bacterias and fungi can be
promising agent for the biodegradation of Low
Density Polyethylene(LPDE).
 This research can be helpful in solving a huge
environmental problem
 Further studies can be carried out on the
organism to increase the yield of the enzymes
that they produce

9. REFERENCES
9
 Shimao M. Biodegradation of plastics. Current Opinion in Biotechnology, 2001; 12: 242–247.
https:// doi.org/10.1016/S0958-1669(00)00206-8 PMID: 11404101
 Sangale MK, Shahnawaz M, Ade AB. A Review on Biodegradation of Polythene : The Microbial
Approach. Bioremediation & Biodegradation, 2012; https://doi.org/10.4172/2155-6199.1000164
 Khanam PN, Mariam AA. Processing and characterization of polyethylene-based composites.
Advanced Manufacturing: Polymer & Composites Science, 2015; 1: 63–79. https://doi.org/10.1179/
2055035915Y.0000000002
 Pramilla R, Vijaya R. Potential biodegradation of low density polyethylene (LDPE) by Acinetobacter
baumannii. African Journal of Bacteriology Research, 2015; 3: 92–95. https://doi.org/10.5897/
JBR2015.0152
 Myint B, Ravi C, Sakharkar MK, Lim CS, Sakharkar RK. Biodegradation of Low Density Polythene
(LDPE) by Pseudomonas Species. Indian J Microbiol, 2012; 3: 411–419. https://doi.org/10.1007/
s12088-012-0250-6.

10. THANK
YOU