Fig 8.
Acid resistance of a ΔPfur81::TT araC ParaBAD fur mutant containing rhamnose-regulated arginine decarboxylase. Arginine decarboxylase rescue was performed by growing strains in EGA medium to stationary phase in the absence of arabinose and presence of 0.1% rhamnose and challenging them with EG medium containing 1 mM arginine at pH 3.0 for 4 h (A) or pH 2.5 for 1 h (B). Survival in all assays was monitored by plating on LB agar containing all necessary supplements. The data shown are the means and SEM from three independent assays. Pairs of data marked with an asterisk are significantly different (P < 0.05). χ11500, Δ(adiA-adiC); χ11118, ParaBAD fur; χ11623, ParaBAD fur PrhaBAD adiAC.