File:Plates photos.JPG

Characterization of BBa_K1314001, BBa_K1314013, BBa_K1314014

On your left, there’s a Burk’s plate which is ammonium repleted. On your right, the plate was nitrogen depleted. We streaked the mutated A.vinelandii onto these plates. Let’s look at the upper part of the plate first. Both clones contain constitutive promoter RFP, but one with strong RBS, the other with weak RBS. Under high Ammonium level, there is strong expression of RFP under constitutive promoter. Under nitrogen depleted condition, there is no growth of A.vinelandii. This proves that the stable genome integration is successful. The mutated A.vinelandii has already lost nitrogenase gene, and thus no longer be diazotrophic.

Now let’s move to the lower left corner of the dishes. We integrated the RFP with nifH promoter into A. vinelandii. On the ammonium rich plate, activation of nifH promoter RNA polymerase is suppressed and thus the downstream RFP expression is poor, giving white clones. On the other plate, we can still see some expression of RFP but with poor overall growth. In the last quarter, the healthy wild type A.vinelandii with normal nitrogenase expression is green and grows better compared to the mutated A.vinelandii.