Team:UCL/Tests
From 2014.igem.org
Stage 01: Extraction of useful BioBrick plasmids from iGEM 2014 Distribution Kit
Registry ID | Name / Function | Source | Size | |
---|---|---|---|---|
|
BBa_K314103 | IPTG-inducible LacI Expression Cassette | Spring 2014 BioBrick Distribution. Plate 1, Well 4D. | 1638 bp |
|
BBa_J04450 | RFP Coding Device | Spring 2014 BioBrick Distribution. Plate 4, Well 4B. | 1069 bp |
|
BBa_R0010 | IPTG-inducible LacI Promoter | Spring 2014 BioBrick Distribution. Plate 3, Well 4G. | 200 bp |
|
BBa_B0034 | Ribosomal Binding Site (RBS) | Spring 2014 BioBrick Distribution. Plate 4, Well 1N. | 12 bp |
|
BBa_K518012 | RBS + RFP + double Terminator | Spring 2014 BioBrick Distribution. Plate 1, Well 18C. | 828 bp |
|
BBa_K206000 | pBAD Strong Promoter | Spring 2014 BioBrick Distribution. Plate 3, Well 14A. | 130 bp |
|
BBa_R0011 | LacI-Regulated, Lambda pL Hybrid Promoter | Spring 2014 BioBrick Distribution. Plate 2, Well 6D. | 55 bp |
|
BBa_B0012 | Transcription Terminator for E. coli RNA Polymerase | Spring 2014 BioBrick Distribution. Plate 2, Well 2B. | 41 bp |
N = Transformed from Distribution Kits, but not used in experiments; ! = Problematic parts (see Parts Registry), were not used.
We plan to create a complete synthetic azo dye decolourising device in E. coli which incorporates several different independent enzymes that act on azo dyes and their breakdown products. After evaluating their individual breakdown characteristics, we aim to investigate the potential synergistic action of these enzymes in a single synthetic E. coli device and design a bioprocess which could be used to upscale the method to an industrial context.
In an industrial setting, these enzymes would work sequentially in a bioreactor with preset dynamic conditions. First, azoreductase will cleave the azo-bond (N=N), producing a series of highly toxic aromatic amines. Then, these compounds will be oxidised by lignin peroxidase, laccase and bacterial peroxidases, completing decolourisation and decreasing toxicity levels.
The complementary action of azoreductase, lignin peroxidase, laccase, and bacterial peroxidases will be studied in order to find out the best possible approach of sequential reaction, and this core degradation module will be extrapolated to other areas such as BioArt projects and work on algal-bacterial symbiosis.
Stage 02: Identification of useful genes for making new BioBricks
This non-specific enzyme was isolated from Bacillus subtilis, although it is also found in other bacterial species. It starts the degradation of azo dyes by cleaving the azo bond.
The products of this cleavage varies greatly among different dyes, but are generally aromatic amines. This azo cleavage does not only occur with azo dyes, but also with other molecules like Sulfasalazine. We will isolate this enzyme from B. subtilis and convert it to BioBrick format via polymerase chain reaction (PCR).
Stage 03: Transforming E. coli with azo-reductase plasmids
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.
Stage 04: Diagnostic digest of azo-reductase plasmids
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.
Stage 05: Creation of azo-reductase BioBrick parts from plasmids
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.
Stage 06: Diagnostic digest of azo-reductase BioBrick parts
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.
Stage 07: Assembling azo-reductase BioBrick Device(s)
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.
Stage 08: Characterisation of azo-reductase BioBrick devices
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.