INTRODUCTION - ALPHAPROTEOBACTERIA Flashcards
Categorizes bacteria into taxa
based on rRNA sequences
Bergey’s Manual
Characteristics of Prokaryotes:
One circular chromosome, not in a membrane
No histones
No organelles
Peptidoglycan cell walls
Binary fission
No peptidoglycan cell wall but some species
has pseudopeptidoglycan in their cell wall
Archaea
mythical greek god who could assume
many shapes
Proteus
largest group of bacteria; most gram negative and chemoheterotrophic
bacteria arisen from common photosynthetic
ancestor
Proteobacteria
proteobacteria that are
capable of growth with very low levels of
nutrients
Alphaproteobacteria
Alphaproteobacteria have unusual morphology, include protrusions
such stalks or buds known as?
Prosthecae
Agriculturally important bacteria capable of
nitrogen fixation in symbiosis with plants, and several plant and human pathogens.
Alphaproteobacteria
Types of Alphaproteobacteria
- Pelagibacter (Pelagibacter ubique)
- Nitrogen-fixing bacteria (Azospirillum)
- Produce acetic acid from ethyl alcohol (Acetobactereceae, Granulibacter)
- Obligate intracellular parasites (Rickettsia, Ehrlichia)
- Have prosthecae (Caulobacter, Hyphomicrobium)
- Plant pathogen (Rhizobium, Agrobacterium)
- Human pathogen (Bartonella, Brucella)
- Chemoautotrophic (Nitrobacter, Nitrosomonas)
- Obligate intracellular parasites (Wolbachia)
Identifying characteristics of bacteria.
Gram stain reaction
Cellular morphology
Oxygen requirements
Nutritional properties
Protein builders of the cell responsible for translation and reading the order of amino
acids and linking amino acids together.
Ribosomal ribonucleic acid (rRNA)
The
process our cells use to make proteins.
Translation
Most abundant microorganism on earth, located
in the oceans.
Pelagibacter
Size of pelagibacter
0.3mm
derived from ubiquitous - found
everywhere
Ubique
Grows in close association w/ the roots of plants, especially tropical grasses.
Uses nutrients secreted by plants, in return fixes
nitrogen from the atmosphere
Nitrogen-fixing bacteria
significant in tropical grasses, sugarcane, corns
Nitrogen fixation
Industrially important aerobic organism
that convert ethanol into acetic acid (vinegar)
Acetobactereceae
(Acetobacter & Gluconobacter)
Emerging pathogen found in patients w/ chronic
granulomatous disease
Granulibacter
Bergey’s 1st Edition: Genera that are grouped closely - reproduce only w/in a
mammalian cell.
Rickettsia, Coxiella, Chlamydia
Gram negative rod-shaped (coccobacilli) bacteria; transmitted to humans by insect & tick bites unlike
Cociella
Rickettsia
Enters by inducing phagocytosis, reproducing by binary fission; responsible for spotted fever group, arthropod- borne. In humans, infections damage the
permeability of blood capillaries - results in spotted
rash
Rickettsia
Gram-negative, rickettsia-like bacteria
live obligately w/in white blood cells
Ehrlichia
Transmitted by ticks to humans, cause a sometimes fatal disease
EHRLICHIA (Ehrlichiosis)
Most common infectious bacterial genus in the
world
that lives only inside the cells of their host (in
insects) (known as endosymbiosis)
Wolbachia
could reduce the ability of Wolbachia
infections and may compromise the ability to block
virus transmission
Heat stress
The phenomenon which:
1. Wolbachia-Infected F + Normal/infected males = offspring: healthy, Wolbachia-positive
2. Wolbachia-negative F + Wolbacia-positive M = offspring do not match
Cytoplasmic
incompatibility
Found in low-nutrient aquatic environments
(lakes) and feature stalks that anchor organism to surfaces
Caulobacter
Caulobacters have prosthecae because of?
constant changing
flow of water
Caulobacter prosthecae uses:
• Increases their nutrient uptake
• Increase surface-to-volume ratio of the cell
Found growing in laboratory water baths
Hyphomicrobium
Infect the roots of leguminous plants
Rhizobium & Bradyrhizobium (common name: rhizobia)
Presence of rhizobia in roots leads to formation of this thing that creates symbiotic relationship; resulting to nitrogen fixation
Nodules
Has the ability to invade plants
Do not induce root nodules or fix nitrogen
Used in genetic engineering
Agrobacterium
Causes a disease called crown gall
Agrobacterium tumefaciens
gram negative bacillus
Bartonella
Infected area - may appear swollen & red w/
round, raised lesions & can have pus
Infected person - have fever, headache, poor
appetite, exhaustion
Bartonella henselae
Small non-motile coccobacilli & obligate parasites
of mammals and cause the disease ______ that survive phagocytosis
Brucella, Brucellosis
How do you acquired brucellosis?
• Direct contact w/ infected animals or by
consumption of raw milk or cheese
• Human -cuts in the skin, through mucous
membranes (inhalation & eating contaminated
meat)
Bacteria that oxidize nitrogen for energy
and fix CO2
Energy sources are reduced nitrogenous
compound
Chemoautotrophic Bacteria (Nitrobacter, Nitrosomonas)
