Composite

Part:BBa_K3598048

Designed by: Yuting Yang   Group: iGEM20_Beijing_4ELEVEN   (2020-10-17)


AOX1 Promoter_α factor secretion signal_CEN1HC-Br_AOX 1 Terminator

The circuit we transformed into Pichia Pastoris to produce AMP CEN1HC-Br.

Part demonstration

Figure 1. Part demonstration

The AOX1-CEN1HC-Br is a composite part consisting of an AOX1 promoter, a CEN1HC-Br coding sequence, and an AOX1 terminator. It is designed for the production of our AMP CEN1HC-Br. We inserted the sequence of the system onto vector pPIC9K and transferred the plasmid into Pichia pastoris GS115 genome. The recombinant strain was cultured for CEN1HC-Br production.

Experiments and Results

GDP 20 was produced by fermentation in BMMY medium, 5% methanol was added every 24 h to induce its expression. Sampling the fermentation medium every 24 h, and the supernatant was used to test the antibacterial effect for AMP was secreted extracellularly.

We tested the antimicrobial potency of CEN1HC-Br fermentation supernatant by adding it to plates inoculated with P. acnes and E. coli MG1655. From the results (Figure 2&3), it can be inferred that the fermentation product's effect of killing E. coli MG1655 and P. acnes are not significant for the inhibition zones are quite unclear. That may be caused by the low concentration of antimicrobial peptides in the fermentation broth.

Figure 2. Plate verification of CEN1HC-Br on P. acnes
Figure 3. Plate verification of CEN1HC-Br on E. coli

Then, we verified the antibacterial potency of CEN1HC-Br by adding the fermentation broth to liquid culture inoculated with E.coloMG1655 and P.acnes, 25% was added in verification to E. coli and 20% added to P. acnes. The OD600 were measured at 12 h for E.coli, while P.acnes was measured at 48h for its low growth rate. The results were shown in Figure 5&6, from which we can infer that the fermentation product was quite effective in inhibting the growth of E. coli MG1655 and P. acnes. Although the actual yield of CEN1HC-Br is not measured, the verifications of antimicrobial potency supports the functionality of this part.

Figure 5. OD600 verification of 25% fermentation broth CEN1HC-Br on E. coli
Figure 6. OD600 verification of 20% fermentation broth CEN1HC-Br on P.acnes

Sequence and Features


Assembly Compatibility:
  • 10
    COMPATIBLE WITH RFC[10]
  • 12
    INCOMPATIBLE WITH RFC[12]
    Illegal NotI site found at 1311
  • 21
    INCOMPATIBLE WITH RFC[21]
    Illegal BamHI site found at 937
    Illegal XhoI site found at 1191
  • 23
    COMPATIBLE WITH RFC[23]
  • 25
    INCOMPATIBLE WITH RFC[25]
    Illegal AgeI site found at 1377
  • 1000
    COMPATIBLE WITH RFC[1000]
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