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Flashcards in Bacteria diversity Deck (13):
1

cyanobacteria

-larger than other bacteria
-all carry out oxygenic photosynthesis
-all are autotrophs
-photosynthesis in thylakoids
-have cells walls
-contain peptidoglycan
-gram negative cell wall
-lowest nutritional requirements of any organisms (primary producers)
-distributed in terrestrial, freshwater and marine habitats

2

Proteobacteria

-many most commonly encountered bacteria
-most metabolically diverse (chemolithotrophs, chemoorganotrophs, phototrophs, facultative organisms that switch from one metabolic lifestyle to another)
-6 classes
-Includes pathogens and non pathogens
-gammaproteobacteria-many grow well in the lab and have becomes important research models and are metabolically and ecologically diverse

3

Firmicutes

-one of two phyla with gram positive cell walls
-low GC gram positives
-includes lactic acid bacteria- fermentation produces lactic acid as an end product
-and non lactic acid

4

Endospore forming Firmicutes

-The best studied genera of endospore formers:
*bacillus-aerobic endospore formers
*clostridium-anaerobic endospore formers
-endospore formers are found primarily in soil
-most are non-pathogenic saprophytic(plants or fungi that live on dead or decomposing matter) soil organisms
-however, some can be dangerous pathogens

5

Tenericutes: the mycoplasmas

-Phylogenitically related to gram positives, but they don’t have a cell wall
-gram negative
-often pleomorphic- the ability of some bacteria to alter their shape or size in response to environmental conditions

6

Actinobacteria

second phylum of gram positive bacteria
high GC gram positives
includes coryneform bacteria (club shaped morphology)

7

Actinobacteria: mycobacteriaum

-mycobacteria have a modified gram positive cell wall
-layer of mycolic acids outside peptidogylcan layer makes them acid-fast (stain)

8

filamentous actinobacteria: streptomyces

-genus of filamentous gram positives
-form branching hyphae and mycleia
-hyphae produces reproductive spores for dispersal- Conidia- not endospores
-most are obligate aerobes
-live in well aerated soils
-give soil its earthy smell-geosmins
-produces substances that kill or inhibit the growth of other microbes- antibiotics

9

Bacteroidetes

-large, heterogeneous phylum of gram negative bacteria
-aerobes and anaerobes
-few unifying characteristics

10

Chlamydiae

-gram negative cell wall type, but lack peptidogylcan
-obligate intracellular parasites
-unique life-cycle with two types of cells
elementary body
-small dense cell, resists drying
-allows infection of new host cells
reticulate body
-larger vegetative cells
-multiply insides an existing host but are not infective

11

Planctomyetes

-budding and appendaged bacteria
-protein stalk used for attachement
-lack peptidoglycan in the cell wall
-some have membrane-bound compartments inside the cell

12

hyperthermophilic bacteria

-there are several deeply branching phyla that consist of hyperthermophilic bacteria
-suggest that the last universal common ancestor (LUCA) may have been a hyperthermophile

13

deinococcus-thermus

-two famous species
thermus aquaticus
deinococcus radiodurans