Team:UCL/Tests

We began our project by identifying a range of BioBrick parts present in the iGEM 2014 distribution kit which we required as part of our cloning strategy. These parts primarily consisted of both constituitive and inducible promoter systems with ribosome binding sites which we could then use in conjunction with our azo-reductase BioBricks to assemble a functional azo dye degrading gene. We also decided that we would use the Red Florescent Protein expressing BioBrick as a control for any further transformation experiments. As the level of DNA present within each plate of the distribution kit is insufficient to perform digest and ligation reactions on it was necessary to transform each of these plasmids into our NEB5alpha competent cells. After growing our transformed cells overnight we then mini-prepped each of them to obtain BioBrick plasmids at suitable concentrations for future experiments.

Our literature search identified a number of bacterial species that have been proven to degrade azo dye compounds including B. subtilis and P. aeruginosa. We were able to obtain a B. subtilis strain for use in our project from ?. We extracted the genomic DNA from this strain using a Promega Wizard Genomic DNA extraction kit so that we could subsequently amplify the azo-reducatase gene (AzoR1) and create our first azo-reductase BioBrick. After completing the genomic DNA extracton we ran a gel to show that we had successfully extracted the B. subtilis genomic DNA.

We were gratefully provided with a set of five plasmids from the Microbial & Enzyme Technology Lab led by Dr Lígia O. Martins at the Universidade Nova de Lisboa. They are currently researching how azo-dye degrading enzymes function and are keen to collaborate with us. These plasmids contained a number of genes encoding azo-dye degrading enzymes from both B. subtilis and P. putida including mutated forms found to exhibit enhanced degradation activity. As the DNA concentration of the plasmids we were sent was insufficient to perform PCR amplification on we transformed each of these plasmids into our E. coli NEB5alpha derivative competent cells. After growing the cells overnight we then mini-prepped each of them to obtain plasmids at sufficient concentrations for future experimental work.

Another azoreductase that we will be using is isolated from Pseudomonas aeruginosa. It functions in the same way as Azoreductase R1 - cleaving the azo bond - but it is intended to work complementary with it, in order to cover a wider spectrum of dyes more efficiently.

Like the previous azoreductase, this BioBrick will be constructed using PCR. A promoter and a ribosomal binding site (RBS) will then be added to create a functioning composite device.

Usually found in white-rot fungi species, its main function in nature is to participate in lignin-degrading processes by these organisms. However, it has also been found to play a role in azo dye degradation and decolourisation.

This enzyme, like laccase, would be incorporated in the second step of the reaction to oxidise the products of the azo bond cleavage, in order to achieve greater detoxification. The sequence for the enzyme will be ordered and synthesised, including the BioBrick prefix and suffix. Again, it will function together with a promoter and a RBS.

Found in B. subtilis, the physiological function of this newly discovered enzyme is still unclear, although it has shown effectiveness in degrading lignin and azo dyes, which makes it useful for us. It is not as effective as PpDyP for most compounds, but very efficient in degrading ABTS (2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)).

The BioBrick will be constructed via PCR.

This enzyme is found in P. putida. Although it is relatively novel, and has not yet been studied in detail, it seem to be an extremely versatile and powerful biocatalyst; it oxidises a wide variety of substrates very efficiently. This will broaden the spectrum of action of our decolourising device, and thus being able to degrade other toxic compounds typically found in industrial wastewaters.

This BioBrick will be constructed via PCR.

This enzyme is found in P. putida. Although it is relatively novel, and has not yet been studied in detail, it seem to be an extremely versatile and powerful biocatalyst; it oxidises a wide variety of substrates very efficiently. This will broaden the spectrum of action of our decolourising device, and thus being able to degrade other toxic compounds typically found in industrial wastewaters.

This BioBrick will be constructed via PCR.

This enzyme is found in P. putida. Although it is relatively novel, and has not yet been studied in detail, it seem to be an extremely versatile and powerful biocatalyst; it oxidises a wide variety of substrates very efficiently. This will broaden the spectrum of action of our decolourising device, and thus being able to degrade other toxic compounds typically found in industrial wastewaters.

This BioBrick will be constructed via PCR.