Figure 2

Efficiency of acetate and other carbon sources with lactose induction. When using sodium acetate, the efficiency of lactose as inductor of protein synthesis is superior to other commonly used carbon sources. The Coomassie stained SDS-PAGE analysis shows 3 μg of the total protein extract before induction (lane 1) and after 20 h post-induction with 1 mM lactose in LB (lane 2) or in PY medium supplemented with 0.4% glycerol (lane 3), 0.4% acetate (lane 4), 0.2% glycerol + 0.2% acetate (lane 5), 0.2% glucose + 0.2% acetate (lane 6) or 0.4% fructose (lane 7).