PET-Degrading Esterase Variants for Activity and Thermostability
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Solution Overview
Problem
There is a need for esterases with improved activity and/or thermostability to enhance the efficiency of polyester degradation processes, particularly for polyethylene terephthalate (PET), as existing esterases are not sufficiently effective in degrading plastics and recycling them into monomers for reuse.
Innovation Solution
Development of novel esterases with specific amino acid substitutions, such as S256C and N207C, that exhibit increased activity and thermostability, allowing for more efficient degradation of PET into monomers and oligomers, with enhanced adsorption and stability at high temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing esterases are used for PET degradation, then the degradation process can proceed, but the activity and thermostability are insufficient for efficient plastic waste degradation and recycling
Solution Approach 1:
The patent applies parameter changes by modifying specific amino acid residues in the esterase protein structure (e.g., positions 256, 207, 212, 181, 66, 62, 220, 93, 248, 26, 15, 17, 115, 112, 133, 145, 150, 155, 156, 165, 173, 188, 190, 200, 201, 202, 240, 243, 260, 262) to alter the enzyme's physical and chemical properties. These mutations result in esterases with enhanced catalytic activity toward PET and improved stability at elevated temperatures, directly resolving the contradiction between productivity and reliability
Solution Approach 2:
The patent creates composite functional properties by combining multiple amino acid substitutions within a single esterase molecule. The synergistic effect of multiple mutations (e.g., combinations of residues at positions 256, 207, 212, 181, 66, 62, 220, 93, 248, 26, 15, 17, 115, 112, 133, 145, 150, 155, 156, 165, 173, 188, 190, 200, 201, 202, 240, 243, 260, 262) produces an enzyme with both high degradation activity and enhanced thermostability, effectively addressing the technical contradiction
2Productivity
If existing esterases are used for polyester degradation, then some degradation occurs, but the efficiency is insufficient to make the process competitive and effective for large-scale plastic waste recycling
Solution Approach 1:
The patent modifies kinetic and thermodynamic parameters of the esterase enzyme through amino acid mutations, resulting in higher catalytic turnover rates and improved substrate binding affinity. These parameter changes directly enhance polyester degradation efficiency and reduce processing costs, making the recycling process more competitive on an industrial scale
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The novel esterases demonstrate at least 10% greater PET degrading activity and increased thermostability, enabling more effective plastic waste degradation and recycling into reusable monomers and oligomers.
Implementation Method 1
esterases are able to catalyze the hydrolysis of a variety of polymers, including polyesters
Implementation Method 2
enzymes may accelerate hydrolysis of polyester containing material, and more particularly of plastic products, even up to the monomer level
Implementation Method 3
with enhanced adsorption and stability at high temperatures
Data Source
AI summary
The present invention relates to novel esterases, more particularly to esterase variants having improved activity and/or improved thermostability compared to the esterase of SEQ ID NO: 1 and the uses thereof for degrading polyester containing material, such as plastic products. The esterases of the invention are particularly suited to degrade polyethylene terephthalate, and material containing polyethylene terephthalate.