Classification of Microbes
Types of microbes and their discovery
What is Microbiology?
Microorganism (aka microbe)- an organism or virus too small to be seen without the aid of a microscope.
Life as we know it would not exist without microorganisms.
- Help obtain nitrogen essential for the survival of plants
- Aid in digestion
- Decompose wastes and enriches soil
- Used in production of food such as wine and cheese
- Used to produce vaccines and antibodies
- Cause disease (colds, tuberculosis, malaria, and AIDS)
- Threats of bio-terrorism and epidemics/pandemics
Early Years of Microbiology
Dutch tailor, merchant, and lens grinder. Learned to make glass lenses to examine the quality of the cloth he was using as a tailor. Curiosity ensued and Leeuwenhoek began observing other other items under the lens.
The lenses Leeuwenhoek created were able to see 200x the actual size of the items observed.
Leeuwenhoek made detailed observations of the specimens he saw in his lenses. He called the specimen "animalcules" which we now know as microbes.
Types of Microbes
Bacteria -Single-celled prokaryotic organisms having cell walls made of peptidoglycan, a molecule not found anywhere else in nature
Archaea - Single-celled prokaryotic organisms without peptidoglycan in their cell walls.
Viruses - Acellular, non-living infectious agents.
- Some are normal flora that naturally inhabit the human body and are helpful or at least not harmful.
- Some are used to make enzymes for detergent and antibiotics.
- Many are pathogens that cause disease (e.g. E.coli, S.aureus, L.monocytogenes)
- Similar to bacteria with the exception of peptidoglycan.
- No known Archaea cause disease in humans.
Other Organisms of Importance to Microbiologists
- many cause disease
- lab technicians diagnose infections of parasitic worms by finding microscopic eggs and immature stages in blood, fecal, urine, and lymph specimens.
Using your notes take 5 minutes to complete the following
- Describe the world-changing scientific contributions of Leeuwenhoek.
- List six groups of microorganisms
- Explain why protozoa, algae, and non-microbial parasitic worms are studied in microbiology.
Fungi - Eukaryotic organisms that have cell walls and obtain food from other organisms.
Protozoans -Single-celled eukaryotes that lack a cell wall and have animal-like characteristics, in their cell structure and nutritional needs.
Algae -Eukaryotic, unicellular or multicellular photosynthetic organisms with simple reproductive structures.
- Can be quite large - mushrooms, or they can be very small, such as tiny molds and yeasts.
- As important decomposers of dead organisms, fungi are essential to recycling matter in living systems.
- Some fungi cause disease.
- Most protozoans live in water
- Some live in human hosts and are able to cause disease.
- Range in size from microscopic, single-celled organisms to giant kelp.
- Algae are more plant-like than animal-like, in that they make their own food from carbon and sunlight energy (photosynthesize).
- Most algae are beneficial, even critical for life on earth. Few cause disease.