Post on 06-Apr-2019
transcript
Bacteria classification
• Domain Bacteria: Kingdom Eubacteria (“true”)
• Domain Archea: Kingdom Archaebacteria (“ancient”)
• All bacteria were previously combined under Kingdom Monera
* ALL bacteria are prokaryotic
Kingdom: Archaebacteria “ancient”
• Autotrophic
• Cell walls with NO peptidoglycan
• Live in extreme environments
1. Methanogens- no oxygen, make
methane gas
2. Thermophiles- very hot water
3. Halophiles- very salty conditions, 10x saltier than ocean water
Kingdom: Eubacteria “true”
• Largest and most diverse of the bacterial kingdoms
• Found everywhere
• Most are HETEROTROPHIC
• Cell walls are present with peptidoglycan
• Many have flagella that aid in movement
How do Bacteria Reproduce?
• Most reproduce asexually through binary fission. ( Dividing in half; identical offspring)
• Some reproduce sexually by conjugation connecting at their pili. (cell to cell contact; new combination of genes)
endospores • Thick wall
• Resistant to heat, dryness, etc
• May survive for years in harsh conditions
• When conditions are favorable, the bacteria will grow from the spore
• Example: ANTRHAX
How are Bacteria Classified?
• cell shape
• cell wall –Archaea and the Bacteria
–Gram+ bacteria and Gram- bacteria
• respiration
• nutrition
Three different shapes:
– Coccus (spheres)
– Bacillus (rods)
– Spirillum (spirals)
Two different arrangements:
– Strepto (chains)
– Staphylo (clusters)
Cell Wall: Gram+ vs. and Gram-
Color
Purple
Red
Amount of peptidoglycan
More
Less
Toxicity
Less
More
Antibiotic effective against?
Most of the time
Not always
Feature Gram + Gram -
Gram +
Gram –
the lipid layer on the outside makes it hard for antibiotics to work on G-
Peptidoglycan – the tan rods in the diagram; lots in Gram +, little in Gram -
Nutrition Types • AUTOTROPHS
– Photosynthetic—use pigments to capture light energy to convert to chemical energy ex. cyanobacteria
– Chemosynthetic—use inorganic molecules or organic molecules to make amino acidsproteins; live in soil and nitrify ammonia ex. sulfur bacteria & methanogens; nitrifying bacteria (Nitrobacter spp.)
• HETEROTROPHS
– Principal decomposers (along with fungi)
– Many produce antibiotics (ex. Streptomyces)
– Some fix nitrogen (ex. Rhizobium)
Diseases caused by Bacteria:
* Tuberculosis
* Anthrax
* Lyme disease
* E. coli
* Bubonic plague
*Typhoid fever *Cholera
*Strep throat *Dental cavities
*diphtheria *pneumonia
Beneficial Bacteria: There are some bacteria you’ve just got to love!
* Bacteria is used to make certain foods like cheese and yogurt.
* To manufacture plastics and many pharmaceuticals.
* Digests cellulose in animals
* Sewage treatment plants
* Medicines like insulin
Mutualistic bacteria: the fish provides the bioluminescent bacteria under its eye with organic materials, the fish uses its living flashlight to lure prey and to signal potential mates.
Questions to Ponder
• Why are bacteria important organisms in the ecosystem?
• What are the shapes and arrangements of bacteria and how can these be used in classification?
• Describe bacterial diseases including cause, symptoms, and transmission.
• In what ways are bacterial beneficial to us? Explain.