Microbial Effects of Temperature, pH, and Oxygen Tolerance in BIOL 2042

What is TDT in microbiology?

Time-Temperature Deactivation, indicating how long and at what temperature a microorganism is killed.

What does TDP stand for?

Thermal Death Point, the lowest temperature at which a microorganism is killed in a given time (typically 10 minutes).

What temperature is optimal for E. coli growth?

37ºC

What is the effect of temperature on enzymes?

Temperature can affect enzyme activity and stability, influencing processes like prodigiosin production.

What are the classifications of oxygen tolerance in bacteria?

Aerobes, anaerobes, facultative anaerobes, and microaerophiles.

What is commensalism?

A relationship between two organisms where one benefits and the other is neither helped nor harmed.

What is the purpose of an anaerobic box in microbiology?

To create an oxygen-free environment for the growth of anaerobic bacteria.

What is the role of ascorbic acid in the anaerobic box?

It acts as a reducing agent in the gas generator pouch to remove oxygen.

What is the significance of pH in bacterial growth?

pH affects enzyme function and can influence the growth of bacteria; extreme pH levels can be toxic.

What is the relationship between E. coli and Clostridium sporogenes in the GI tract?

E. coli uses oxygen, creating an anaerobic environment that benefits C. sporogenes.

What is the procedure for growing anaerobes?

Inoculate plates with organisms from FTM tubes, label them, and incubate one anaerobic and one aerobic.

What is the effect of pH on bacterial enzymes?

Bacterial enzymes can be inhibited or activated depending on the pH level of their environment.

What is the incubation temperature for anaerobic plates?

37ºC

What happens to culture media due to bacterial waste products?

Bacterial waste can change the pH of the culture media, potentially making it toxic.

What is the effect of temperature on microbial growth?

Different temperatures can promote or inhibit the growth of specific microorganisms.

What is the purpose of inoculating broth tubes at different pH levels?

To observe the effect of pH on the growth of microorganisms like S. cerevisiae.

What is the significance of the glucose medium in pH experiments?

It provides a carbon source for fermentation, allowing observation of pH effects on microbial growth.

What is the incubation time for the mixed culture of E. coli and C. sporogenes?

48 hours at 37ºC.

What does the term 'facultative anaerobes' refer to?

Organisms that can grow in both the presence and absence of oxygen.

What is the role of microaerophiles?

They require low levels of oxygen for growth, typically less than atmospheric levels.