Does E coli produce beta galactosidase?

Yes, E coli is able to produce beta galactosidase. However, the gene which codes for beta galactosidase (lacZ gene) is typically switched off unless lactose is present. The lacZ gene is one of the three enzymes which facilitate the ability of E coli to break down lactose. The two other enzymes are lac Y and lac A. Lac Y is a permease which assists the entry of lactose into cells. Lac A is a trans-acetlayse. Its function in lactose metabolism is still not fully known. When lactose is not present, only a small amount of beta galactose molecules are found in the cell. This helps to conserve energy in the cell during enzyme synthesis. Upon the addition of lactose under normal conditions, there is a rapid increase in the quantity of beta galactosidase, reaching approximately 5000 molecules per cell within minutes after introducing the sugar. The genetic information for all three enzymes is found in a single mRNA transcript, which is referred to as polycistronic.