Ming Yan

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Purification and Reengineering of
Plastic-Degrading Enzymes

• Ming Yan

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Background

• Plastic bags are made from polyethylene (PE), a
  polymer consisting of long chains of the ethylene
  monomer (C2H4).
• Species of bacteria belonging to the Streptomyces
  genus are capable of producing polyethylene-degrad
  ing enzymes.

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Streptomyces
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Streptomyces

• Streptomyces viridosporus
• Streptomyces badius
• Streptomyces setonii

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How is Biodegradability Measured?

• Weight loss
• Tensile strength loss
• measured stress at fracture of the specimen
• Changes in percent elongation
• extension of material under load
• Changes in polyethylene molecular weight
  distribution
• polydispersity

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Project Ideas

• Aim 1 To purify and characterize the
  biodegradable polyethylene-degrading enzyme(s)
  from bacterium belonging to the Streptomyces
  species
• Aim 2 To enhance the biodegradability of the
  polyethylene by increasing the efficiency of the
  degrading enzymes through protein engineering
  techniques

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Aim 1

• Inspiration
• Enzymes identified for anaerobic degradation of
  polyethylene glycol (PEG)
• Technical Difficulties with the isolation methods

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Aim 2

• To enhance the biodegradability of the
  polyethylene by increasing the efficiency of the
  degrading enzymes through protein engineering
  techniques
• Methods
• Score system
• Protein engineering

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Protein-Engineering
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More Ideas