Table 2.

Plasmid pC22lux and chromosomalndi::Tn5-luxAB expression in S. meliloti 1021 wild-type and tspO and fixLmutant strains after exposure to low oxygen tension for 8 ha

Regulatory mutant backgroundPlasmid pC22luxChromosomalndi::Tn5lux
0 h8 h0 h8 h
Aerobic1% O2Aerobic1% O2
Wild type493 ± 19.7344 ± 10.72,632 ± 158.05.2 ± 0.250.4 ± 0.055.8 ± 5.0
fixL::Tn5 883 ± 35.2116 ± 4.51,064 ± 49.711 ± 0.90.08.8 ± 0.72
tspO::Tn1721 344 ± 6.9101 ± 2.0453 ± 12.90.00.00.0
  • a Luminescence values are defined as described in Materials and Methods. Data are presented as the mean ± the standard deviation (n = 9).