Lab Exercise 10- Endospore Stain

When the mother cells lyse, they release ________ into the environment

free spores

Clostridium perfringens is the etiological agent of _______ and food infections

gas gangrene.

Bacillus cereus causes

gastroenteritis

What are Clostridium and Bacillus known to cause?

microbial food-borne illnesses (food poisoning) due to the difficulty in destroying all the endospores during food preparation and storage.

The part of the cell surrounding the mature endospore is called the

sporangium

Clostridium tetani is the etiological agent of the ______ disease and also produces a potent neurotoxin.

tetanus

A cel lacking an endospore is called a

vegetative cell

Describe incubation period and temperature of NSM plates

30 degrees celsius for 5-7 days

Which medium is used to view endospores under a simple gram stain test?

A Nutrient Sporulation Medium due to ample endospore production on this medium

What happens during bacterial sporulation?

A part of the cytoplasm is separated and encased within a few protective barriers of keratin giving rise to an endospore.

What are three main endospore forming Gram-positive rod shaped bacterial genera?

Bacillus, Clostridium, and Sporolactobacillus

The primary stain 5% malachite green does not easily penetrate endospores under normal conditions, so it is applied to the bacterial smear over

Boiling (steaming) water

What are some shapes of the endospores?

Circular (spherical) or oval (elliptical/cylindrical)

An accurate stain result of a culture is best obtained by using an ______ phase culture, typically around 16-18hrs and not more than _______hrs

Exponential; 24hrs

T orF? An endospore is larger than a vegetative cell.

False, endospores are smaller than vegetative cells.

T or F? Endospores are the same as spores produced by fungi.

False, they are different

The presence of the exotoxins produced by these bacteria (Clostridium and Bacillus) in the consumed food can lead to

Food intoxications

What are endospores highly resistant to?

Radiation, heat, and chemicals.

What is a Gram-positive coccus shaped endospore former?

Sporosarcina

What are the locations of some endospores?

Terminal, central and subterminal, located somewhere between the center and the end of the cell.

What is sporulation?

The highly ordered process of making spores

T or F? Endospores are metabolically inactive and unable to divide.

True

T or F? Endospores are only found in Gram-positive bacteria.

True

When are endospores formed?

Under nutrient limitation, endospores are formed but only within certain bacterial cells.

Describe the endospore staining method that was first described in 1933 by Schaeffer and Fulton

Uses a 5% malachite green solution as the primary stain and safranin as the counterstain.

When can food infection occur?

When large numbers of viable cells are ingested with the food.

The presence of _________________ in food leads to botulism

botulinum toxin

Clostridium botulinum is the causative agent of

botulism