Question

first two pictures are what is to be answered, and the bottom four are the results used to answer them.

thats all the infor given

Answer 1

Q1:Pasteurization of milk is defined as a process to heat milk at 720C for 15 seconds and allow it to cool quickly. Pasteurization leads killing of harmful bacteria’s such as typhoid fever, brucellosis etc. and also increases the shelf life of milk. Based on this information and the bacterial culture pictures (milk and deoxycholate agar medium) provided in the result, we can see that in unpasteurized milk the bacterial colonies are dense and not discrete at the given dilutions starting from 10-1 to 10-4. However, in pasteurized milk there are less dense colonies which demonstrate that in the starting pasteurized inoculum some of the bacteria have been killed. Therefore, it is clear that the pasteurization has remained successful.