Bacterial Spores: Structure and Function

What is the role of safranin in a staining process?

Fixative
Primary stain
Decolorizer
Counterstain (correct)

What is ropiness commonly associated with?

Bacterial contamination (correct)
Mold growth
Enzymatic spoilage
Yeast fermentation

What is the function of water in a staining process?

Fixative
Counterstain
Decolorizer (correct)
Primary stain

What is the primary purpose of a counterstain?

To enhance the contrast of the primary stain (A) Signup and view all the answers

Which bacteria is often responsible for ropiness in food matrices?

Bacillus subtilis (A) Signup and view all the answers

What is the role of a decolorizer in a staining process?

To remove excess stain (C) Signup and view all the answers

What is the impact of ropiness on food quality?

Spoils food appearance (C) Signup and view all the answers

Which of the following foods is more susceptible to ropiness?

Bread products (C) Signup and view all the answers

What is the most common use of safranin in a staining process?

As a counterstain (B) Signup and view all the answers

What is the relationship between Bacillus amyloliquefaciens and ropiness?

B. amyloliquefaciens is also involved in ropiness (D) Signup and view all the answers

What is the function of small acid-soluble proteins (SASPs) in spores?

Bind to DNA and protect the spore from UV, dehydration, and dry heat (C) Signup and view all the answers

What is the primary function of Mannitol in MYPA?

Carbon source (B) Signup and view all the answers

What is the purpose of adding egg yolk to MYPA?

To allow sporulation and detect proteolytic activity (D) Signup and view all the answers

What is the mechanism by which dehydration confers resistance to chemicals in spores?

It inactivates enzymes, making the spore metabolically inert (A) Signup and view all the answers

What is the optimal temperature range for the growth of Bacillus cereus?

45-55°C (B) Signup and view all the answers

What is the role of dipicolinic acid (DPA) in spores?

It dehydrates the spore and intercalates in DNA, stabilizing the DNA against heat and UV radiation (A) Signup and view all the answers

What is the function of spores in terms of protecting bacterial cells?

To protect the bacterial cells against UV radiation, dehydration, and extreme pH deficiency gradients (D) Signup and view all the answers

What is the generation time of Bacillus cereus?

~15-20 min (A) Signup and view all the answers

What are the characteristics of Bacillus cereus?

Gram-positive, spore-forming, catalase-positive, and facultative anaerobic (D) Signup and view all the answers

What is the characteristic of spores that makes them resistant to chemical agents and disinfectants?

Their ability to dehydrate and inactivate enzymes, making the spore metabolically inert (D) Signup and view all the answers

What is the characteristic of this organism?

It can reproduce quickly (B) Signup and view all the answers

What is a requirement for this organism to reproduce?

No specific requirements (B) Signup and view all the answers

What is true about this organism's reproduction?

It can reproduce on its own (C) Signup and view all the answers

What is the state of this organism when it is not active?

Dormant (B) Signup and view all the answers

Why is this organism able to reproduce quickly?

Because it does not need other spores (D) Signup and view all the answers