Microbiology Flashcards
Investigation into numbers of bacteria in milk:
What bacteria are present in milk?
Lactobacillus and Bifido species
What can give milk a sour taste?
Milk Sugar can be fermented into lactic acid
What can fermented milk restore?
a healthy gut flora, it may be consumed by people who are otherwise intolerant to milk
Aseptic Technique Step 1 + 2: what should be done before and after test?
wash hands
clean the work surface
Aseptic technique Step 3: what type of dish and substance is used?
petri dish with sterile agar gel
Aseptic technique step 4: what should be done to petri dish and why?
It is inoculated close to Bunsen Burner: updraughts move airborne microbes away from the plate
Aseptic technique step 5: how should universal jars be used treated?
keep lid in crook of little finger, flame mouth of jars before and after use
Aseptic technique step 6: what is used for transfer of substances?
sterile syringes used and kept on sterile area
Aseptic technique step 7,8,9 : how should sample be added to petri dish
only lift petri dish high enough to add sample
return petri dish lid and secure with adhesive tape strips
ensure initials date and practical time are written around edge of plate
How do you complete serial dilutions?
insert 9.9 cm^3 sterile water into each universal jar before adding milk product, progressively dilute by adding 0.1 cm^3 of each solution.
What is a haemocytometer?
an glass slide with 3x3 grid, has a specific depth, for visual counting of the number of cells in a blood sample or other fluid under a microscope.
What are the shapes of bacteria? (classification)
Cocci (spheres), Bacilli (rods), Spirillum (waved), Vibrio (comma like), Coccobacillus, Spirochete (spiral)
What are some examples of cocci bacteria?
Staphylococci, Streptococci
What are some examples of Bacilli bacteria?
Bacillus anthracis, Salmonella typhi
What is an example of Spirillum bacteria?
Helicobacter pylori
What are protoctists + key characteristics?
Eukaryotes
Have a nucleus
DNA in non circular chromosomes
What is an example of vibrio bacteria?
Vibrio cholerae
What is an example of Spirochete bacteria?
leptospira
What is an example of coccobacillus bacteria?
haemophilus influenzae
What is a colony?
a cluster of cells, or clone, which arises from a single bacterium or fungal spore by asexual reproduction