How Biotechnology has enhanced cheese-making process

1. How Biotechnology has enhanced cheese-making process Biotechnology

2. Objectives • Explain how biotechnology has improved the process of making cheese

3. Terminology • Rennin • Chymosin (Chy-max) • Curds • Whey

4. Cheese-Making Technology • Cheese-making- • Originally achieved by letting naturally occurring bacteria turn the milk sour

5. How cheese is made • Milk bacteria have enzymes that convert the sugar lactose to lactic acid. • Lactic acid has an acidic pH • At a low pH, the milk protein, casein, breaks down or denature • Also the proteases found in the bacteria act like scissors and cut the casein into smaller fragments • The denatured casein forms the solids observed in sour milk

6. How cheese is made • The solids are curds • Curds are pressed together to form cheese • The left over liquid is known as the whey Curds from sour milk

7. Which Curdling Agent worked the Best? • Speculate as to why?

8. Milk Culture was • 1:5 ratio of buttermilk to whole milk • Why buttermilk added to the milk? • Buttermilk has an active culture of Lactobacillus bacteria that can act as starter for curdling milk

9. Curdling Agents – What makes them different? • Rennin – purified protease from cow’s stomach that cleaves the milk protein casein into smaller fragments that settle out as curds • Chy-max –Rennin genetically engineered to be made in Fungi. Fungi produce the enzyme faster and in larger amounts than a cow can make.

10. Genetic Engineering of Chymosin

11. Think-Pair-Share Why would the production of chymosin be advantagous for the cheese-maker? 3

12. Industrial process of making cheese • Video on cheese-making

13. Minute Paper You have one minute to write down how cheese making is an application of biotechnology. Be prepared to share. 13