Fig. 4

Comparison of the four strains RD03-RD06, derived from the same host ll-cat01 containing the plasmids pLC0, pLC17, pLC02, pLC01, as biocatalysts for the conversion of pyruvate to α-acetolactate. RD03-RD06 were incubated in an unbuffered solution containing 0.5 M pyruvate at pH 4.6 at OD₆₀₀ = 1.0. RD03 contains the empty cloning vector as negative control (circles). RD04-RD06 contain plasmids over-expressing different α-acetolactate synthase enzymes from L. lactis (ll-ALS) (squares), B. licheniformis WX-02 (bl-ALS) (diamonds) and E. faecalis (ef-ALS) (triangels). A: pH-profile (pH against time [min]). B: delta-pH as indicator for the catalytic activity. C: delta-pH against pH. Because of the generally small errors, the error bars are not indicated here