Team:BAU-Indonesia

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Introduction

Polyethylene is a synthetic polymer that made of long chain monomers of ethylene. It is a thermoplastic commodity mostly used for packaging. About 140 million tonnes of synthetic polymers are produced worldwide annually with their utility escalating at a rate of 12% per annum (Shimao 2001). The most widely used plastics used in packaging are polyethylene (LDPE, MDPE, HDPE and LLDPE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyurethane (PUR), poly(ethylene terephthalate) (PET), poly (butylene terephthalate) (PBT). Polyethylene are resistant against microbial attack, since during their short time of presence in nature evolution could not design new enzyme structures capable of degrading synthetic polymers (Mueller 2006). In order to manage the utility of these polymers in the nature, there are two ways: one is to exploit the microorganisms in degrading polyethylene and the other is to develop artificial polymers susceptible to biodegradation. Subsequently, to gain large-scale acceptance these man-made biodegradable polyethylene should retain all the essential properties of utility by the consumer and when discarded in the environment should demonstrate their degradability more rapidly than the conventional ones (El-Shafei et al. 1998).
Nanda et al. (2010) have reported natural and synthetic PE degradation activity of Pseudomonas sp. that isolated from sewage sludge and household garbage dump. The degradation activity from each Pseudomonas sp. isolates were different between natural and synthetic PE 31,4%-46,2% and 29,1% - 16,3% respectively in loss weight. Some kind of enzymes had a PE degradation activity reported by Guebitz and Cavaco-Paulo (2008) cutinase. Cutinase has recently received much attention because of its potential application for surface modification and degradation of aliphatic and aromatic polyesters, especially polyethylene terephthalate (PET), which is a synthetic aromatic polyester composed of terephthalic acid (TPA) and ethylene glycol) ; however, the number of cutinases, which have been studied regarding PET modification, is still limited, and this limitation may result in the delay of the research toward the practical use of cutinases. Bogor Agricultural University (IPB) iGEM team project is making a synthetic bacteria that can degrade plastic ecspecially PE/PET with a novel degrading enzymes.