To test this, strain Re2437 was cultivated in media under different pH values (5.5, 7.0 and 8.5).
Testing this strain, we found NR accumulation was related to increased cell density (Table 2).
Unfortunately, we were unuable to introduce either of the two plasmids in B. longum subsp. longum CCUG 30698 and therefore could not test this strain.
We tested this mutant strain in the present system, and found that it showed a gradual reduction in growth rate, rather than a sharp stop, at limiting nitrogen levels and low induction levels (Additional file 1: Figure S2).
The pSIP expression system (Sørvig et al. 2003) is well thoroughly tested in this strain and may produce level of the target protein to more than the half of total cellular proteins (Halbmayr et al. 2008).
Furthermore AqF showed a concentration dependent inhibition at the lower concentrations tested for this strain, 25, 12.5 and 6.25 μg/ml.
To test this, a strain containing a chromosomally integrated Pab1-GFP was transformed with either the vector control, gal-Dhh1, or gal-Pbp1 high copy plasmids.
While 4.2% of the T. whipplei CDSs appeared to have diverged in the Twist strain relative to the other 15 strains tested, this value increased to 26.7 % when genes that belong to the WiSP protein family were considered.
Due to the lack of comprehensive sequence information for the rfb loci of all the strains tested, this result may lie in incapable of identifying rfb genes present in the tested strain but absent from the strain Lai-based microarray.
We tested this hypothesis using a strain with constitutive SOS induction due to a defective (null) lexA allele, lexA51(Def), and found that the polBΔ1 lexA51(Def) strain retains a hypermutagenesis phenotype equivalent to the polBΔ1strain (Figure 1A).
