EFFECT OF STARCH PRETREATMENT ON THE MICROBIAL DEGRADATION OF LOW DENSITY POLYETHENE CARRIER BAGS
EFFECT OF STARCH PRETREATMENT ON THE MICROBIAL DEGRADATION OF LOW DENSITY POLYETHENE CARRIER BAGS
No Thumbnail Available
Date
2013-02
Authors
TAFIDA, THERESA AISHATU
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
In this study, a cassava starch/low density polyethene (LDPE) blend was compounded
and the effect of this starch pretreatment on the rate of degradation of synthetic
polyethene carrier bags was tested using bacteria and fungi (as singles and as
consortia) isolated from dump sites. Weight loss and Fourier Transformed Infra Red
Spectroscopy (FTIR) were used as analytical techniques for measuring
biodegradation. Fungi was found to degrade both synthetic LDPE and LDPE/Starch
blend resulting in a weight loss of 3.54% to 19.68% while that obtained from bacteria
gave a weight loss of 1.0% to 18.5% within 30days . Mixed cultures comprising of
both bacteria and fungi gave better results than the individual organisms and addition
of starch was found to greatly enhance the biodegradation of the low density
polyethene carrier bags. FTIR analysis showed the appearance of carbonyl groups in
the LDPE residues after microbial treatments between wavelengths of 1703.67cm-1
and 1872.83cm-1 indicating likely oxidation of the carbon-carbon double bond (C=C)
and various oxidation products formed during the biodegradation. This study
therefore shows that microorganisms with the ability to degrade low density
polyethene carrier bags exist in our natural environment. It has also shown that
blending LDPE with natural polymers such as starch can greatly enhance the
biodegradation of this polymer and that microbial consortia can accelerate the rate of
degradation of this polymer. Therefore finding the right microorganisms and/or their
enzymes that can efficiently and completely biodegrade the recalcitrant polyethylene
into carbon dioxide, water and biomass will go a long way in solving this global threat
and studying the synergism between them will give more insight for future efforts
towards the bio degradation of these polymers
Description
A THESIS SUBMITTED TO THE SCHOOL OF POSTGRADUATE STUDIES,
AHMADU BELLO UNIVERSITY, ZARIA IN PARTIAL FULFILMENT OF THE
REQUIREMENTS FOR THE AWARD OF MASTERS OF SCIENCE IN
MICROBIOLOGY
DEPARTMENT OF MICROBIOLOGY
FACULTY OF SCIENCE
AHMADU BELLO UNIVERSITY, ZARIA, NIGERIA
FEBRUARY, 2013
Keywords
EFFECT,, STARCH PRETREATMENT,, MICROBIAL,, DEGRADATION,, LOW DENSITY POLYETHENE CARRIER BAGS.