Difference between revisions of "Part:BBa K5236012"

Revision as of 11:22, 2 October 2024

BhrPETase M57L

Plastic pollution poses a serious threat to the global environment. One of the potential solutions, enzyme degradation, would be a suitable approach of dealing with plastic wastes. Among all plastic pollutions, more than 10% of them are Polyethylene terephthalate (PET). Thus, our team has been searching for possible PET hydrolases to break down PET. However, according to Nature's publishment on April 27, 2022, traditional PET hydrolases' enzymatic ability of degrading PET are easily affected by the fluctuation of temperature and pH value. Therefore, we decided to artificially mutate wild-type BhrPETase to increase the enzyme’s range of tolerance so that it can efficiently degrade PET under a wider range of environmental conditions, thereby enhance its potential application. BhrPETase was identified by the Shingo group in a metagenomic study on uncultured thermophiles and was deposited into the NCBI database by the group in 2018 and annotated as a PET hydrolase. As one of the most-confident mutants created in our lab, this basic part encodes mutated BhrPETase M57L.

Usage and Biology

To insert our parts into plasmids, we’ve designed primers and performed PCRs. Then, our genes were recombined into plasmids and transformed into chassis. To test if our part codes for the mutated BhrPETase M57L we want and whether the enzyme works, we've completed two large experimental processes. The first step is plasmid construction. And the second is to test the enzymatic activity.

By conducting colony PCR, we are able to test if our parts have been transformed into chassis successfully. The following result of electrophoresis proves that we’ve inserted genes into chassis since the sequence containing our mutated genes has a total of 891 base pairs and the results are in the right location.

After proving that our genes existed in chassis, we need to test if the bacteria can survive as usual with our genes. Thus, we’ve coated the bacteria on nutritional petri dish. And after a night, E. coli grew over the plate our plate, justifying that E. coli can survive with the gene of our part.

We tested whether the bacteria could translate for our protein, and we examined whether our mutated enzyme is more efficient. For this section, we analyzed two results as well. First, the dynamic curve of our enzyme shows its high efficiency in degrading rate. Second, the electrophoresis result of our protein proves that our enzyme can be successfully coded by the parts we designed.

Reference

Lu, Hongyuan, et al. “Machine Learning-Aided Engineering of Hydrolases for Pet Depolymerization.” Nature News, Nature Publishing Group, 27 Apr. 2022, www.nature.com/articles/s41586-022-04599-z. Kato, Shingo, et al. “Long-Term Cultivation and Metagenomics Reveal Ecophysiology of Previously Uncultivated Thermophiles Involved in Biogeochemical Nitrogen Cycle.” Microbes and Environments, vol. 33, no. 1, Jan. 2018, pp. 107–10. https://doi.org/10.1264/jsme2.me17165

Sequence and Features