Difference between revisions of "Part:BBa K1597000"

Revision as of 14:27, 17 September 2015

Salt inducible promoter for B. subtilis

Bacillus subtilis is capable of coping with fluctuating salt concentrations. One of the genes involved is proH, this is an 1-pyrroline-5-caboxylate reductase. A study has shown that this gene is under control of the salt inducible proH promoter. The salt inducible promoter can be activated by a range of salt concentrations, respectively ranging from 0,1M salt up to 1 M. We have cloned this promoter out of the genome of Bacillus subtilis and combined it with tasA (BBa_K1597002) (amyloid-like fibers in the biofilm matrix). To confirm that the salt inducible promoter functions, our construct was placed in B. subtilis comI with the use of BBa_K823023 . B. subtilis ComI strain with salt inducible PproH promoter and tasA construct (tasA) and B. subtilis ComI (comI) were grown on Msgg media with and without salt. After 24 hours thioflavin S (which is an amyloid fiber staining) was added to the biofilms. The biofilms were photographed with white light and fluorescence after 15 min incubation.

With the induction of salt, tasA shows more amyloid fibers are present after 24 hours. This is not the case for the comI strain. This indicates that the salt promoter is indeed activated with salt, causing an overexpression of tasA, which resuls in a more intense dye.

Another validation was performed with the tasA mutant, please look at the page from tasA (BBa_K1597002) .

Sequence and Features