Fig 3.

β-Galactosidase activities of reporter plasmids. L. lactis NZ9000 carrying pNZ8020 (empty vector), pBL58 (P₂₄₄₇-lacZ), or pBL59 (P_IS981::2447-lacZ) was plated onto a GM17 plate containing 80 μg/ml X-Gal. The mean β-galactosidase specific activity ± the standard deviation in six enzymatic activity assays with two independent cultures of exponentially growing L. lactis NZ9000 cells carrying these plasmids was calculated. Cells carrying pNZ8020, pBL58 (P₂₄₄₇), and pBL58 (P₂₄₄₇) with Lcn972 added at 10, 20, and 40 AU/ml produced no activity, while those carrying pBL59 (P_IS981::2447-lacZ) produced 294.2 ± 47.2 ΔmA₄₂₀/min/OD₆₀₀ unit.