Download to read offline
PET
- 1. PLASTIC-EATING BACTERIa Ideonella sakaiensis Preparedby : Hadiah Al Mahdi
- 2. POLYETHYLENE TEREPTHALATE (PET) •PET is widely used in plastic bottles like Carbonate drinks, water bottles, plastic film, microwavable packaging. 56 6.13 PET was produced worldwide in 2013 Recycling million tons
- 3.
- 4.
- 5.
- 6.
- 7. Ideonella sakaiensis • I.sakaiensis was identified in 2016 by a team of researchers from Kyoto Institute of Technology and Keio University, Japan. • The bacterium was named from environmental samples taken in Sakai, Osaka Prefecture, it was given the name Ideonella sakaiensis, strain 201-F6 . • It is capable of breaking down PET plastic which was isolated from outside a plastic bottle recycling facility. .
- 8. Morphology 1) A Gram-stain-negative2) Aerobic 3) Non-spore-forming 4) Rod-shaped bacterium 5)Feed on PET and grew within the pH range 7–7.5 and at 30– 37 ºC SEM image of Ideonella sakaiensis
- 9. Discovery • Researchers collectinga variety of environmental samples of PET debris. • They were taken and test tubes containing a defined culture medium supplemented with a PET film as the major carbon source. • After 6 weeks, sample contained a distinct microbial which had formed on the PET film, and the film was showing clear signs of degradation. • It is successfully isolated the bacterium capable of degrading PET.
- 10.
- 11. • Researcher didnot finished yet the work on the genome of bacteria so no clear view about it
- 12. They Identified 20open reading frame (ORF)
- 13. Protein Sequencing Alignment ISF6_4831 •It encodes a putative lipase (PETase) that shares amino acid sequence identity and catalytic residues with a hydrolase enzyme (TfH ) from thermophilic actinomycete and cutinase homolog from leaf-branch (Lcc)
- 14. Protein Sequencing Alignment ISF6_0224 •It is protein sequence encoded to (MHETase) and matches to the tannase family, which is known to hydrolyze the ester linkage of aromatic compounds.
- 15. PCR-DGGE analysis • Usedto identify bacteria strain. • DGGE profiles of 16S rDNA of microbial consortia The arrow indicates the band corresponding to I. sakaiensis 201-F6.
- 16. RNA-Seq transcript levelsof ISF6_4831 and ISF6_0224 on four different carbon sources • I. sakaiensis was grown in medium containing maltose, TPA-Na, PET film, or BHET), and the mRNAs from exponentially growing cells were subjected to RNA-Seq analysis.
- 17. Mechanisms of hydrolysis •Terephthalic acid, used principally as a precursor to the polyester PET used to make clothing and plastic bottles..
- 18. Future Recommendation • Improvethe bacterium to make it more powerful, and genetic engineering might be applicable. • One way of speeding things up would be to transfer the genes that make the two enzymes into a faster growing bacterium like Escherichia coli
- 19. Inquires..!! • Is thereany possibility for the bacteria to be more abundant in any other regions in the world?? • Can there be any additional applications to maximize the benefits of such ability?? • Is it possible to identify similar strains which similar abilities??
- 20. Conclusion • PET isused in plastic products, and its accumulation in the environment has become a global concern. • (PETase and MHETase) are required to enzymatically convert PET efficiently into its two environmentally benign monomers,terephthalic acid and ethylene glycol. • PET degradation using microorganisms and enzymes consumes less energy and is a more environmentally friendly option. • Researches achieving an ideal model for PET recycling, so long as we are able to enhance the activity level and stability of these newly discovered microbial enzymes.
- 21.
Editor's Notes
- #3 PET is made from petroleum and is widely used in plastic bottles like Carbonate drinks, water bottles, peanut butter jars, plastic film, microwavable packaging. The amount recycled accounts for just 37% of the total production volume of PET bottles (6.13 million tons) About 56 million tons of PET was produced worldwide in 2013 alone 15.4 million tons were for food and liquid containers, 3.2 million tons for packaging films, and 38 million tons for synthetic fibers. Currently the main method employed for recycling PET waste uses chemical techniques, but these processes come with many problems, such as the vast amount of energy consumed.
- #10 Researchers collecting a variety of environmental samples of PET debris in a search for bacteria which relied on the plastic for carbon growth. They were taken and test tubes containing a defined culture medium supplemented with a PET film as the major carbon source. The bacterium was observed to utilize two distinct enzymes that reacted with water to break down plastics After 6 weeks, one sediment sample contained a distinct microbial consortiumwhich had formed on the PET film, and the film was showing clear signs of degradation. From the microbial consortium, we then successfully isolated the bacterium capable of degrading PET. The bacterium was observed to utilize two distinct enzymes that reacted with water to break down plastics
- #11 It has the ability to break down the PET polymer by 2 enzymes (PETase and MHETase
- #14 Protein is responsible for hydrolyzes PET,that yield MHET
- #15 Hydroxyethyl terephthalic acid (MHET) Protein is responsible for the conversion of MHET to TPA and EG in I. sakaiensis
- #16 (left, a consortium with PET degradation activity; right, a consortium without PET degradation activity) were compared.
- #21 Compared with chemical processes,