Implicit Factors

Question 1

What are the three broad categories we must consider when determining whether or not a microbe can grow in a particular food product?

Answer 1

Intrinsic, Extrinsic, and Implicit.

Question 2

When Salmonella is subjected to a pH treatment of 5.5, what might be some of the effects observed when the adapted microbes are challenged?

Answer 2

Reference slides 8-10.

Question 3

What type of proteins are chaperons? What do they do?

Answer 3

Reference slide 11.

Question 4

Flavobacterium psychrophilum is a type of bacteria that infects cold water fish. How might its membrane differ from that of a mesophile growing at 37 C? What if it infected tropical fish? What would be different about it’s membrane?

Answer 4

See slides 12-15.

Question 5

In yogurt, what are the ways in which Streptococcus thermophilus stimulates growth of Lactobacillus delbrueckii, and vice versa?

Answer 5

See the last slide of this lecture…

Question 6

Can you describe in words the four examples of implicit factors we discussed: 1) Effect of growth phase on heat tolerance; 2) Effect of pre-adaptation to stresses on surviving future stresses; 3) Adapting to cold temperatures; 4) How microbes can stimulate growth of each other

Answer 6

If you can do this, you are in really good shape with this information!