[Identification and characterization of a novel polyamide hydrolase]

Area of Science:

• Biotechnology
• Environmental Science
• Polymer Chemistry

Background:

• Non-naturally degradable plastics pose significant environmental challenges.
• Biological plastic degradation offers mild reaction conditions and product recyclability.
• Limited research exists on the biological depolymerization of polyamides.

Purpose of the Study:

• To identify and characterize enzymes capable of polyamide depolymerization.
• To investigate the potential of a novel enzyme for plastic recycling.

Main Methods:

• Screening a plastic depolymerase library using 4-nitropropionanilide as a model substrate.
• Obtaining and expressing a Meiothermus ruber-derived enzyme (MrABH) in Escherichia coli.
• Purifying MrABH via affinity chromatography and analyzing its catalytic properties on polyamide substrates.

Main Results:

• A novel polyamide-hydrolyzing enzyme, MrABH, was identified.
• MrABH demonstrated optimal stability at pH 8.0-10.0 and 30°C, with peak activity at pH 9.0.
• The enzyme effectively depolymerized PA6 and PA66 into monomers and oligomers, showing similar activity on ester and amide bonds.

Conclusions:

• MrABH shows significant potential for the biological depolymerization and recycling of polyamide plastics.
• This discovery contributes to developing sustainable solutions for plastic waste management.