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

• 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 Wall

Chloroplasts

Cell Nucleus

Organelles/ Vacuoles

Cytoplasm

Cell Membrane

Classification of Microbes

Prokaryotic vs Eukaryotic

NuclearMembrane

Classification of Microbes

Prokaryotic

• Domain– Archaea

• Domain– Bacteria

Domains and Kingdoms

Eukaryotic

• Domain Eukarya– 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

• Molds

• Yeast

• Fungi

Fungi [Eukaryotic]

Bacteria Morphology (shapes)

• Coccus (cocci)• spheres

• Bacillus (bacilli)• rods

• Spirillus (spirilli)• spiral, corkscrew (spirochetes)

Bacteria Morphology (shapes)

Coccus (cocci)– diplococcus

– streptococcus

– staphylococcus

Gonorrhea

pneumonia

Staph infections

Bacteria Morphology (shapes)

Bacillus (bacilli)

E. colicholera

Legionnaire’s diseasemeningitis

Bacteria Morphology (shapes)

Bacillus (bacilli)

salmonella

peptic ulcers

tuberculosis

whooping cough

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?