Questions: 11. Web research : Find out how scientists were able to make lactase enzymes. Describe the process with some detail. For example what type of enzyme is involved in the process?

Scientists have developed various methods to produce lactase enzymes, which are crucial for breaking down lactose, a sugar found in milk and dairy products. Here is a detailed description of the process:

1. Source Identification:

   • Microbial Sources: Lactase enzymes are commonly derived from microorganisms such as fungi (e.g., _Aspergillus oryzae_ and _Kluyveromyces lactis_) and bacteria (e.g., _Escherichia coli_). These organisms naturally produce lactase to metabolize lactose.

2. Gene Cloning and Expression:

   • Gene Identification: Scientists first identify and isolate the gene responsible for lactase production in the chosen microorganism.
   • Cloning: The lactase gene is then cloned into a suitable vector (a DNA molecule used as a vehicle to transfer genetic material into a cell).
   • Transformation: The vector containing the lactase gene is introduced into a host cell (often _E. coli_ or yeast cells) through a process called transformation.
   • Expression: The host cells are cultured under conditions that promote the expression of the lactase gene, leading to the production of the lactase enzyme.

3. Fermentation:

   • Cultivation: The transformed host cells are grown in large fermentation tanks. The conditions (such as temperature, pH, and nutrient supply) are carefully controlled to maximize enzyme production.
   • Induction: In some cases, the production of lactase is induced by adding specific substances to the culture medium that trigger the expression of the lactase gene.

4. Purification:

   • Cell Lysis: The host cells are harvested and lysed (broken open) to release the lactase enzyme.
   • Filtration and Centrifugation: The cell debris is removed through filtration and centrifugation, leaving a solution containing the lactase enzyme.
   • Chromatography: The enzyme solution is further purified using techniques such as affinity chromatography, where the lactase enzyme binds to a specific substrate on a column and is then eluted (washed out) in a purified form.

5. Characterization and Quality Control:

   • Activity Assays: The activity of the purified lactase enzyme is tested to ensure it effectively breaks down lactose.
   • Stability Tests: The stability of the enzyme under various conditions (e.g., temperature, pH) is assessed to ensure it will function properly in its intended application.

Lactase is a type of enzyme known as a β-galactosidase. It catalyzes the hydrolysis of lactose into glucose and galactose, which are simpler sugars that can be easily absorbed by the human digestive system.

Scientists produce lactase enzymes by identifying and cloning the lactase gene from microorganisms, expressing it in host cells, and then purifying the enzyme through a series of biochemical techniques. The resulting lactase enzyme, a β-galactosidase, is used to help individuals who are lactose intolerant digest dairy products.