Plastics are one of the most versatile materials and widely used in the world. Polyethylene terephthalate (PET) is one of the most commonly used plastics.
Generally, three methods have been reported for PET plastic recycling including physical, chemical, and biological processes. However, physical and chemical recycling have limitations such as the inability to achieve closed-loop recovery and cause secondary pollution. Therefore, in contrast, biological recycling seems to be a sustainable development approach.
Articles have published in Nature has shared their fantastic discovery of the mutant LCC (mLCC) as the most efficient enzyme that can degrade PET.
Base on the facts, our group decides to enhance the activity of mLCC by proceeding two approaches, which are constructing a fusion protein of mLCC and hydrophobins and using the technique of Bacillus subtilis surface display.
Biodegrading PET takes two process, adsorption and degradation. The fusion protein was made to enhance the efficiency of adsorption, since the surface of PET film is hydrophobic and the surface of mLCC is hydrophilic. Constructing a mLCC-hydrophobin fusion protein will enhance the efficiency due to the unique properties of amphiphilicity and self-assembly of hydrophobins.
The second approach we use is Bacillus subtilis surface display. By combining mLCC with the anchor protein which forms the fusion protein, mLCC will be immobilized on the Bacillus subtilis cell surface to obtain a recyclable whole-cell biocatalyst, which can reduce costs and make the mLCC more efficient degrading PET.