Topic 6 -1 Flashcards
(14 cards)
What is the purpose of using aseptic techniques in culturing microorganisms?
To ensure safety and prevent contamination with unwanted organisms
Aseptic techniques involve sterilizing equipment and maintaining a sterile environment during the culturing process.
What is an agar plate?
A solid medium containing nutrient agar on which organisms can grow
Nutrient agar is mixed with nutrient broth, poured into a Petri dish, and allowed to set.
What are selective media used for?
To grow specific types of organisms by discouraging the growth of unwanted organisms
This can be achieved by adding or omitting certain nutrients or including antibiotics.
What is the significance of flaming equipment in aseptic technique?
It ensures the sterility of the equipment used for culturing
Flaming is done with a Bunsen flame before inoculation.
What is the definition of aseptic in the context of culturing microorganisms?
Everything is sterile until inoculation, allowing only intended organisms to grow
A culture dish cannot be sterile because it must contain living organisms.
What are the ideal conditions for growing microorganisms in a culture?
- Nutrients
- Suitable temperature and pH
- Usually access to O2
These conditions allow microorganisms to increase in number to a measurable level.
What is a common error in exam answers regarding the culturing of microorganisms?
Suggesting that bacteria can be cultured on plain agar or in an empty Petri dish
It is better to specify nutrient agar for successful growth.
What are some problems associated with culturing microorganisms?
- Pathogens may enter the culture
- Safe organisms may mutate to dangerous forms
- Contamination with unwanted organisms can spoil an investigation
These issues can jeopardize the integrity of the culture and results.
What precautions should be taken when culturing microorganisms?
- Adequate O2 supply
- Culture temperature 30°C or below
These measures help prevent the growth of pathogens and ensure safe culturing conditions.
Fill in the blank: A culture provides microorganisms with ideal conditions for growth, including _______.
[nutrients]
Other factors include suitable temperature, pH, and usually access to oxygen.
True or False: Culturing microorganisms allows their numbers to increase to the point where they can be seen or measured.
True
This is one of the primary purposes of culturing microorganisms.
What temperature is recommended for culturing microorganisms to avoid the growth of human pathogens?
30°C or below
Higher temperatures, like human body temperature, can encourage the growth of harmful pathogens.
What is the role of nutrient broth in the preparation of an agar plate?
It provides the nutrients needed for microorganisms to grow
Nutrient broth is mixed with molten agar before being set in a Petri dish.
Fill in the blank: A common culture condition is _______ for 5 days.
[20°C]
This temperature is widely used for culturing various microorganisms.
