MICROBES
• Microscopic life forms that cannot be seen
by the unaided eye
• May be plant or animal
• May be prokaryotic or eukaryotic
Importance of Microbes
• Pathogenic
• Help cure / prevent disease
• Break down organic matter to inorganic
forms (decompose, recycle)
– Autotrophs (inorganics)
– Animals (organics)
– Decomposers (inorganics, external digestion!)
Importance of Microbes
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Spoil foods
Make / flavor foods
Petroleum & Coal: unrecycled remnants
Decay wooden structures
Corrode iron & steel, damage concrete
Food source
Allow fouling community establishment
Classification of Microbes
Plant vs Animal cell
Cell Membrane
Cytoplasm
Organelles/ Vacuoles
Cell Nucleus
Chloroplasts
Cell Wall
Classification of Microbes
Prokaryotic vs Eukaryotic
Nuclear
Membrane
Classification of Microbes
Domains and Kingdoms
Prokaryotic
• Domain
– Archaea
• Domain
– Bacteria
Eukaryotic
• Domain Eukarya
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Protista
Fungi
Plantae
Animalia
Archaeabacteria [Prokaryotic]
• Methanococcus jannaschii
– 1st archaea to be genetically sequenced
Bacteria [Prokaryotic]
• Blue-green algae
– Cyanobacteria
Protista [Eukaryotic]
• Micro- & macro-algae
Fungi [Eukaryotic]
• Molds
• mycelia = ‘body’
• hyphae = threads
Fungi [Eukaryotic]
• Molds
Molds (Ich, fin-tail rot)
2x
Fungi [Eukaryotic]
• Molds
• Yeast
Fungi [Eukaryotic]
• Molds
• Yeast
• Fungi
Bacteria Morphology (shapes)
• Coccus (cocci)
• spheres
• Bacillus (bacilli)
• rods
• Spirillus (spirilli)
• spiral, corkscrew (spirochetes)
Bacteria Morphology (shapes)
Coccus (cocci)
Gonorrhea
– diplococcus
– streptococcus
– staphylococcus
Staph infections
pneumonia
Bacteria Morphology (shapes)
Bacillus (bacilli)
cholera
E. coli
meningitis
Legionnaire’s disease
Bacteria Morphology (shapes)
Bacillus (bacilli)
peptic ulcers
salmonella
whooping cough
tuberculosis
Bacteria Morphology (shapes)
Spirillus (spirilli)
Growth (culture) of MICROBES
• Natural media
– Extracts
– Infusions
• Synthetic media
– Nutrient broth
– Nutrient agar
Broth Solidifiers
Gelatin
• Animal protein
• Melts @ 20°C
• Digested by microbes
Agar
• Plant carbohydrate
• Melts @ ~100°C,
solidifies @ ~42°C
• NOT digested by
(terrestrial) microbes
Which is useful for incubation at human body temperature?