TABLE 1 

Doubling times of recombinant glycine riboswitch B. subtilis strains grown in increasing glycine concentrationsa

StrainMean doubling time (min) ± SEM at glycine concn (%) of:
00.250.51
NCIB 3610 (parental)70.0 ± 2.680.0 ± 2.782.8 ± 1.7108.9 ± 5.8
WT76.2 ± 2.387.9 ± 2.190.3 ± 3.9110.6 ± 4.4
ΔgcvT-gcvPB73.7 ± 2.7 (1.0)b110.1 ± 4.8c (1.3)118.8 ± 5.1c (1.3)127.7 ± 9.8 (1.2)
M181.7 ± 5.2 (1.1)98.7 ± 7.5 (1.1)98.7 ± 11.0 (1.1)116.5 ± 11.6 (1.1)
M269.3 ± 3.2 (0.9)77.9 ± 4.5 (0.9)84.1 ± 3.8 (0.9)116.3 ± 12.5 (1.1)
M3116.8 ± 7.8c (1.5)143.6 ± 4.0c (1.6)143.4 ± 0.0c (1.6)153.4 ± 5.0c (1.4)
M476.7 ± 2.8 (1.0)92.3 ± 2.5 (1.0)94.3 ± 3.4 (1.0)110.6 ± 5.0 (1.0)
M584.6 ± 2.8c (1.1)115.3 ± 7.8c (1.3)122.8 ± 7.0c (1.4)123.8 ± 13.8 (1.1)
M6101.4 ± 7.4c (1.3)87.8 ± 1.7 (1.0)96.1 ± 1.0 (1.1)106.1 ± 7.7 (1.0)
M780.0 ± 5.7 (1.1)91.9 ± 5.6 (1.1)91.2 ± 6.3 (1.0)106.7 ± 4.8 (1.0)
M878.2 ± 3.5 (1.0)90.6 ± 3.5 (1.0)97.3 ± 3.0 (1.1)110.6 ± 10.3 (1.0)
M1+M280.0 ± 1.9 (1.1)95.5 ± 4.5 (1.1)103.1 ± 5.0 (1.1)133.5 ± 6.8c (1.2)
M1+M476.1 ± 6.1 (1.0)107.2 ± 4.9c (1.2)106.7 ± 2.3c (1.2)126.9 ± 7.8 (1.2)
M2+M380.8 ± 2.8 (1.1)89.6 ± 3.1 (1.0)96.4 ± 3.8 (1.1)116.1 ± 4.3 (1.1)
M2+M578.6 ± 1.8 (1.0)100.4 ± 1.9c (1.1)112.3 ± 6.7c (1.2)126.8 ± 9.7 (1.2)
M3+M4137.4 ± 6.5c (1.8)143.6 ± 4.0c (1.6)148.1 ± 2.4c (1.6)148.1 ± 2.4c (1.3)
  • a Strains were grown in M9 minimal medium with increasing glycine concentrations at 37°C with shaking (225 rpm) for 24 h. Each value is the mean of three or more independent experimental replicates ± the standard error of the mean across biological replicates.

  • b In parentheses is the strain doubling time relative to that of the wild-type (WT) recombinant strain.

  • c Strains grew significantly worse than the wild-type recombinant strain at the corresponding glycine concentration (P < 0.05).