Why in News?

• Scientists are exploring microbial degradation as a solution to plastic pollution

• Bacteria and fungi are being studied for their ability to break down plastics

Ideonella sakaiensis

• A bacterium with a unique ability to degrade polyethylene terephthalate (PET)

Scientific details:

• Gram-negative, rod-shaped, motile, non-sporing, non-pigment-producing, monotrichous bacterium

• Genus: Ideonella

• Family: Comamonadaceae / Sphaerotilaceae

Discovery:

• Found by Japanese researchers Kohei Oda and Kenji Miyamoto (Kyoto Institute of Technology and Keio University)

• Discovered in PET-contaminated soil

Habitat:

• Oxygen-rich moist soil and sewage sludge

  • Especially areas enriched with plastic waste

Advantages:

• Can completely degrade PET into environmentally safe building blocks

• Degraded products can serve as food for I. sakaiensis and other organisms

Other Microbes Decomposing Natural Polymers

• Cellulose – plant fibres

• Chitin – found in fungi and insects

• Cutin – found on leaf surfaces

Plastic-Degrading Microbes

• Gordonia – degraded polypropylene by about 23%

• Arthrobacter – degraded polystyrene by about 19.5%

Waxworms (Galleria mellonella)

• Can eat plastic bags

• Naturally pests in beehives, feeding on honeycomb

  • Honeycomb is chemically similar to polyethylene, the main component of plastic bags

Quick Facts: Polyethylene Terephthalate (PET)

• Strong, stiff synthetic fibre and resin, part of the polyester family

• Most commonly used in bottles and food packaging

• Produced by polymerization of ethylene glycol and terephthalic acid