Introduction to microbiology Flashcards
What are the major differences between prokaryotes and eukaryotes?
Eukaryotic cells have a membrane-bound nucleus and prokaryotic cells do not.
Genetic material in prokaryotic cells is loose.
How many microbes are in/ on the human body?
100 x 10^14
How do we name bacteria?
Genus name: capital letter, italics, Latin/ Greek descriptive eg. Staphylococcus/ streptococcus
Followed by species name: starts with lower case, italics, Latin eg. Aureus, pyogenes
Genus species eg. Staphylococcus aureus
What staining do we use for bacteria and what is the meaning?
GRAM staining
Gram Positive: stains PURPLE eg. staphylococcus aureus
Gram Negative: stains PINK eg. Escherichia Coli
Gram staining helps to identify genus level.
Viruses
Akaryotic
Size: 0.01-0.2 um
Composed of: nucleic acid and protein coat
Fungi
Size: 2um-20cm
Eukaryotic cell structure
unicellular (yeast) or multicellular (mushrooms)
Protozoa
Size: 1-200 um
Eukarytoic cellular organisation but no cell wall
ingest solid food particles
How are microbes used in food?
spoilage, preservation, source of food, food production, food poisoning
eg. quorn= mycoprotein from fungal mycelium
What bacteria are used in the food industry?
Corynebacterium glutamicum- lysine, glutamic acid
Erwinia sp. - pectinase
Bacillus sp.- amylase
Acetobacter sp.- vinegar
Lactobacillus sp. - lactic acid, yoghurt
What is cholera?
Caused by vibrio cholerae (gram negative rod bacterium).
Classic disease of poverty and poor sanitation
Transmission: faecal-oral through contaminated water
Causes rice-water stool causing death by shock due to dehydration
Why are microbes good for us?
inhibit pathogens, produce vitamins, induce antibody production, we use it to process sewage.