Part:BBa_K1841000
nisin resistancy
The promoter BBa_K1841011 has a great usage in both E. coli and L. casei. Also, rbs BBa_K1841012 fuctions well in both bacteria. The gene BBa_K1841001 nisI, in the research from Torsten et al. revealed that the highest level of acquired nisin tolerance was achieved after coordinated expression of all four nisin resistence genes, containing nisI, nisF, nisE, and nisG. Functional analyses provided evidence that NisI acts as a nisin-sequestering protein that expels nisin molecules from the cytoplasmic membrane into the environment.
With this design, we are able to express nisin resistance in E. coli and L.casei. It may become a safer way for selection for fear of antibiotic safety concern.
If you want to use this part, just use the prefix and suffix to cut our part and ligate it with the vector without antibiotic resistant. Then transform it into bacteria. Finally, you can get the nisin resistant bacteria.
Nisin has a stronger ability to kill gram positive bacteria. Hence, if you want to transform it to gram negative bacteria, you should add EDTA to weaken its cell wall.
Sequence and Features
- 10COMPATIBLE WITH RFC[10]
- 12COMPATIBLE WITH RFC[12]
- 21COMPATIBLE WITH RFC[21]
- 23COMPATIBLE WITH RFC[23]
- 25COMPATIBLE WITH RFC[25]
- 1000COMPATIBLE WITH RFC[1000]
Experiment 1:
nisin resistance
nisin sensitivity of E. coli transformed with the plasmid expressing nisI in different concentration.
From the picture, we can know that in the low concentration of the nisin, E. coli can resist nisin. You can see that there are no evident zone of inhibition in 0, 20, 50 IU. Therefore, we can assure that E.coli can expel nisin and survive in the environment that do not have many bacteria toxic chemical.
Experiment 2:
nisin resistance with EDTA addition
nisin sensitivity of E. coli which cell wall is weakened by EDTA and transformed with the plasmid expressing NisI in different concentration of nisin.
We can know that under the EDTA process, E.coli will have a weaker cell wall to resist nisin. Furthermore, we can easily deduce the factor, like cell wall thickness that influence the ability of nisin resistance. From the picture, we can easily tell that the nisI gene have the ability to resist nisin because of the colony decrease.
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