Blog

An organism that grows best at temperatures ranging from -5 to 20 oC. What is its temperature classification?

Organisms that grow in  2 -10% oxgyen concentration are classified as _________________.

A new bacterial pathogen has been discovered which can cross the blood-brain barrier and cause bacterial meningitis. What temperature classification would you assign to this bacterium?

An important aspect for bacterial growth is membrane fluidity. What is the effect of excessively high temperatures on membrane fluidity?

Give the full name of the media MSA

Which of the following bacteria is an obligate anaerobe?

What is the counterstain used in the Gram staining procedure?

This is a blood agar plate. Identify the hemolysis in section A

Serial ten-fold dilutions are made from a broth culture of Bacillus subtilis in order to determine the number of bacteria in the culture.  Following the dilution series, 0.1 ml of a 1:10,000 (1 x 10-4) dilution is plated, the plate is incubated, and 110 colonies are counted.  Calculate the number of bacteria in the original Bacillus subtilis culture. Don’t forget units! Make sure your answer reflects proper scientific notation! Use the ^ to denote an exponent, i.e. 1 x 10-4 would be written as 1 x 10^-4. Note: Don’t forget the units. No points without units!

Name a media that selects for Gram Positive bacteria.