BACTERIAL PHYLA Flashcards
- small group
- thermohpilic-hyperthermophilic, chemolithotrophic
- hot environments
- obligate anaerboes except G. Aquifex
Phylum 1- Aquificae
derive their energy by oxidizing inorganic molecules
chemolithotrophic
- G -
- can live 95 C
- GOT 85 C
- thermophilic and hyperthermophilic
- chemolithoautotrophs - Kreb’s for CO2 fixation
- hydrothermal environments
- aerobic, only low quantities of O2
- non-sporulating
- motile
- metabolic versatility
- H2S or S2O32 (thiosulfate) as energy source/substrate
G. Aquifex
phylum if Genus Aquifex
Aquificae
- aerobic chemoorganotrophic bacteria
- best studied: G. Thermus G. Deinococcus
Phylum 2 - Xenobacteria
- G -
- thermophilic
- immotile/motile w/ flagella
- more activte at higher temp.
- more thermostable than most other enzymes
- GOT 70 C-75 C (min: 37-45 C, max: 79 C)
- some w/ lower GOT, ~6O C (min: 35-40 C, max: 70 C)
- GOpH 7.5-8.0
- GOpH for thermus trains 5.1-9.5
G. Thermus
Genus Thermus
Genus Deinococcus
Genera of Phylum Xenobacteria
- incapable of fermentation
- growth substrates: carbohydrates, amino acids, carboxylic acids, and peptides
- monosaccharide - source for single carbons ; pentoses not metabolized
- most Icelandic strains - use sucrose and & maltose, 2 strains - glucose
- proteins hydrolyzed vary by the isolates
- elastin, fibrin, and casein - used by many high temp. strains
- Nitrate - terminal electron strains
- grows anaerobically in the presence but not in the absence of nitrate.
Thermus Strains
- G -
- cell structure w/ tripartite cell envelope
- tripartite CE - plasma membrane, thin middle layer, thicker, irregular outer layer.
- produces Taq DNA
- complete Kreb’s cycle - glyoxylate bypass, isocitrate lyase, malate synthase
Thermus aquaticus
major enzyme used in Polymerase Chain Reactio (PCR) techniques for amplifying DNA
Taq DNA
- G -
- curved, rod
- 1-2 um length, 0.5-0.75 um dm
- chemolithoautotroph
- obligate anaerobe
- motile w/ monotrichous
- unique lifestyle & biochemistry
- eats arsenic
- arsenate for respiration ; most oxidized form of arsenic
- acetate & arsenite - electron donors for energy
- environments rich in arsenite
Chrysiogenes arsenatis (Phylum 3 - Chrysiogenetes)
- small phylum
- chemotrophic & autotrophic
- best studied genera: Thermomicrobium & Chloroflexus
Phylum 4 - Thermomicrobium
- 2 G - chemotrophic species
- lipids made up of 1,2-dialcohols instead of glycerol
Genus Thermomicrobium
- G -
- thermophilic
- filamentous
- anoxygenic phototroph (do not produce O2)
- GOT 35-70 C
- in alkaline hot springs - thick mats
- photosynthesis carried out via bacteriochlorophyll a
- grows in the dark by chemo-organotrophic by aerobic respiration
- ancient genus w/ photosynthetic metabolism
- part way b/w the Purple and Green Sulphur Bacteria
- may be one of the earliest photosynthetic bacteria
Genus Chloroflexus
- survive in the dark if O2 is available
- grew in the dark - dark orange
- grew in sunlight - dark green
Chloroflexus auranticus
- photosynthetic
- 2nd org in ext. - produces O2 as byproduct
- allowed aerobic organisms to develop
- in water
- once thought to be blue-green alage
- green from chlorophyll
- blue from phycocyanin
- phycoerythrin - red ; red+green = brown (some)
- soils, rock, freshwater
- in desert - dormant most of the time
- in aqua. env. - thick mats
- high tolerance of heat and low pH = main autotrophs in hot springs
- symbioses with liverworts, cycads, and ferns
- fungi - best/known symbiosis ; produces lichens
- 1st org. to release O2 into the atmosphere
Phylum 5 - Cyanobacteria
SNAH
- Stigonema
- Nostoc
- Anabaena
- Hapalosiphon
Important genera of Phylum 5 - Cyanobacteria
- Filamentous w/ solitary filaments
- free clusters/macrscopic mats
- cylindrical, longer than wide (2-10 um in dm)
- pale/bright blue-green or olive-green
- heterocyst-forming
- photoautotrophic > oxygenic photosynthesis
- in long filaments of vegetative cells
Genus Anabaena
- Durng times of low env. nitrogen, 1/10 cells -> heterocyst
- supplies neighbouring cells with fixed nitrogen for products of photosynthesis (can no longer perform)
- nitrogenase is unstable in the presence of O2, O2 na nitrogen must be separated
- heterocycts maintain a low level of O2 within the cell
- builds 3 additional layers outside the cell wall = enlarged & rounded apperance
- the rate of O2 diffusion into heterocycts is 100 times lwoer than of vegetative cells
- 1 layer creates an envelope polysaccharide layer - nitrogen is fixed in an oxygen-restricted milleu
- to lower O2 within the cell, photosystem II is eliminated, and the rat of respiration is increased.
Heterocysts
- small phylum
- 17 species
- “Green Sulphur Bacteria”
- contain bacteriochlorophyll a & c/d/e
- LE trapped by BC c, d, & e is chanelled to BC a
- BC a- site of photosynthesis
Phylum 6 - Chlorobia
- G -
- obligate anaerobe
- photoautotrophic
- inc. green sulphur bacteria
- photolithotrophic oxidizers of sulfur
- uti. noncyclic ETC
- non-motile
stagith/curved rod - GOpH 6-7
- habit of “consorting” with other larger, non-phototrophic bacteria
Genus Chlorobium
will be in consrt with a single non-chlorobium cell
Chlorobium spp.
- aggregation
- more than just casual groupings because both Chlorobium and non-Chlorobium cekks divide at the same time
- unknown ecological signifiance
Consortia
- thermophilic
formes dense microbial mats in hot springs with a high sulphide content
Chlorobium tepidum
- G -
- 2nd largest group
- 1534 species, 32.3% of all known bacteria
- Purple Phototrophic Bacteria
- Nitrifying Bacteria
- Spirilla
- Methanotrophs
- Acetic Acid Bacteria
- Free living Aerobic
- Nitrogen Fixers
- Enteric Bacteria
- Bioluminiscent
- Rickettsias
Phylum 7 - Pseudomonadota (Proteobacteria)
- inc. Escherichia
- G -
- non-sporulating
- non-motile/motile w/ peritrichous flagella
- facultative anaerobes
- oxidase-negative
- relatively simple nutritional requirements
- end products, e.. fermenting sugars
Enteric Bacteria
- in intestinal tract of humans & warm-blooded animals (non-dominant)
- nutritional role in the iT - synthesizing vitamins (Vit. K)
- facultative anaerobe
- help consume O2 = rendering the large intesting, anoxic
- mesophilic
- GOT 37-39 C
Genus Escherichia
- bacilli
- straight, rod-like form
- 0.4-0.7 um (1-3 um) in size
- singly or in pairs
- motile
Escherichia coli
- all G + except G. Mycoplasma
- largest group of bacteria
- 2475 species
- 255 genera
- 40% of are in just 6 genera
- divided into their GC ratio
- either High GC or Low GC
Phylum 8 - Firmicutes
G. Lactobacillus - 100 sp.
G. Mycoplasma - 110 sp.
G. Bacillus - 114 sp.
G. Clostridium - 146 sp.
G. Streptomyces - 509 sp.
G. Micrococcus
Genera of Firmicutes w/ numer of species each