Figure 3

Extracellular α-L-rhamnosidase activity and α-L-rhamnosidase gene expression in rhaR ⁺ and Δ rhaR strains. (A) Bar diagram of the relative α-L-rhamnosidase activities secreted by rhaR ⁺ (AR4, AR70, AR198, AR271 and AR256) and ΔrhaR (AR225, AR227, AR237 and AR234) strains after 48 h grown in 1% w/v L-rhamnose. Activities are presented as percentages of those observed in AR198, and values are presented as the mean of at least three independent experiments and their standard deviation. (B) RT-PCR analyses for rhaA and rhaE in rhaR ⁺ and ΔrhaR strains under inducing conditions using RNAs isolated from mycelia obtained after 4 h transfer to 1% w/v L-rhamnose. The actin actA gene (AN6542) was used as a constitutive control for normalization. RNA quality and amount was also verified by ethidium bromide staining of rRNAs (not shown).