Microbiology - Openstax - Ch 4 - Prokaryotic Diversity

Rhizobium bacteria

Alphaproteobacteria -
Responsible for fixing nitrogen in some plants, especially legumes.

Heterotrophic

Organisms that are unable to construct their own food from inorganic sources, and therefore must consume other organisms or organic molecules from the outside environment. Function as consumers or decomposers in food chains.

Bioremediation

The use of living organisms to detoxify and restore polluted and degraded ecosystems

Pathogen

a bacterium, virus, or other microorganisms that can cause disease.

symbiotic relationship

The relationship between two species that live in close association with each other

Prokaryote

A unicellular organism that lacks a nucleus and membrane-bound organelles

Halophiles (halobacteria)

Anaerobic bacteria that thrive in environments with very high salt concentrations

Community

A group of interdependent organisms inhabiting the same region and interacting with each other

Population

a group of organisms of the same species populating a given area

Cooperative Interactions

benefit the populations

Competitive Interactions

Competition for resources between populations

Symbiosis

A close relationship between two species that benefits at least one of the species.

Mutualism

A relationship between two species in which both species benefit

Amensalism

a relationship between organisms of two different species in which one is unaffected and the other is negatively impacted by the association

Commensalism

A relationship between two organisms in which one organism benefits and the other is unaffected

Neutralism

Neither species benefits or is harmed

Parasitism

A relationship between two organisms of different species where one benefits and the other is harmed

Microbiome

all of the microorganisms that live in a particular environment, such as a human body

resident microbiota

Organisms that live on or in a body.

transient microbiota

microorganisms that are only temporarily found in the human body, and these may include pathogenic microorganisms

Gram-negative bacteria

Bacteria that have complex cell walls with less peptidoglycan but with lipopolysaccharides. Very toxic and hard to treat.

Proteobacteria (Gram Negative)

Phylum of Gram-Neg bacteria divided into the following groups: Alphaproteobacteria
Betaproteobacteria
Gammaproteobacteria
Deltaproteobacteria
Epsilonproteobacteria

Carl Woese

Devised a system of classification based on the cellular organization of organisms

Alphaproteobacteria

Most are capable of growing with very low levels of nutrients
Many have stalks or buds known as prosthecae

Oligotrophs

organisms capable of living in low-nutrient environments such as deep oceanic sediments, glacial ice, or deep undersurface soil.

Oligo-

few or small

pleomorphic

organisms that are variable in shape and size

Rickettsia rickettsii

Alphaproteobacteria - Rocky Mountain Spotted Fever

Chlamydia

Alphaproteobacteria - A sexually transmitted disease, the most common in developed countries, caused by the bacterium Chlamydia trachomatis.

elementary bodies

A small dormant body that serves as the agent of transmission between hosts cells in the chlamydial life cycle.

reticulate body

The form of chlamydiae that replicates and produces elementary bodies within the mucosal cell

Betaproteobacteria

Class of diverse Gram-negative bacteria in the phylum Proteobacteria often growing between aerobic and anaerobic areas. Eutrophic

Eutrophic

Organisms that require an environment with large amounts of organic nutrients.

Bordetalla

Betaproteobacteria - Whooping Cough

Burkhoderia

Betaproteobacteria - Nosocomial Infections

Neisseria

Betaproteobacteria - Gonorrhea and Meningitis

Gammaproteobacteria

Largest and most diverse class of proteobacteria containing numerous human pathogens

enteric

pertaining to the intestines

facultative anaerobes

can survive with or without oxygen

Serotype

Strain or variation of the same species of bacteria

Coliform

a type of bacteria found in human and animal wastes

fastidious

Difficult to grow and require specific nutrients

Legionella pneumophila

Gammaproteobacteria - Legionnaire's disease

Salmonella typhi

Gammaproteobacteria - Typhoid Fever

Escherichia coli (E. coli)

Gammaproteobacteria - a type of food-borne illness that is spread
through contaminated food or water, or from other infected people or animals.

Aliivibrio fischeri

Gammaproteobateria - bioluminescent bacterium that colonizes the light organ of hawaiian squid

Deltaproteobacteria

gram negative, predators on other bacteria

Bdellovibrio

Deltaproteobacteria - Attacks other gram-negative bacteria

Desulfovibrio

Deltaproteobacteria - can be used to reduce sulfur and toxic or radioactive waste.

Myxobacterium

Deltaproteobacteria - Gram-negative, coccoid bacteria forming colonies (swarms)
Live in soil; can move by gliding; used as a model organism for studies of intercellular communication (signaling)

Epsilonproteobacteria

Smallest group of proteobacteria

Microaerophilic

requires only a small amount of oxygen

Campylobacter jejuni

Epsilonproteobacteria - often infects chickens. May infect humans via undercooked meat causing severe enteritis

Helicobacter pylori

Epsilonproteobacteria - can damage the inner lining of the stomach causing chronic gastritis, peptic ulcers and stomach cancer.

Non-proteobacteria

Gram-Neg
Very different evolutionary background from proteobacteria

Leptospira

Non-proteobacteria - Infects rodents and domestic animals, can be found in shallow water reservoirs

Borrelia

Non-proteobacteria - Spirochete - Lyme Disease

Treponema

Non-proteobacteria - Spirochete - Syphilis

Spirochetes

spiral-shaped bacteria that have flexible walls and are capable of movement

Axial filiments

Also called endoflagella
Found in spirochetes
Anchored at one end of a cell
Rotation causes cell to move like a corkscrew

CFB group

Phylogenetically diverse group in which they share some similarities, fermenters that thrive in digestive tracts.
Cytophaga, Fusobacterium, and Bacteroides

Cytophaga

Aquatic, gliding bacteria
Important in the degradation of raw sewage

Fusobacteria

Anaerobic
Are found in the mouth; cause dental abscesses

Bacteroides

prevalent inhabitants of the human large intestine accounting for 30% of the gut microbiome

Planctomycetes

Typically found in aquatic environments, reproduce via budding than binary fission.

Phototrophic bacteria

a large and diverse category of bacteria that do not represent a taxon but, rather, a group of bacteria that use sunlight as their primary source of energy.

oxygenic photosynthesis

Production of ATP from UV radiation, oxygen is produced

anoxygenic photosynthesis

Production of ATP from UV radiation, oxygen is NOT produced

bacteriochlorophyll

Photosynthetic pigment used by purple and green bacteria and are green, purple, or blue. May contain some carotenoids.

purple sulfur bacteria

oxidize hydrogen sulfide to elemental sulfur and sulfuric acid

green sulfur bacteria

use sulfide for oxidation and produce large amounts of green bacteriochlorophyll

Purple non-sulfur bacteria

Use substrates other than sulfur for oxidation.

Green Non-Sulfur Bacteria (Chloroflexi)

Use substrates other than sulfur for oxidation.

Cyanobacteria (blue-green algae)

Blue-green color from chlorophyll. Perform oxygenic photosynthesis, produce megatons of oxygen, responsible for creating oxygen-rich atmosphere.

Gram-positive bacteria

Bacteria that have a thick peptidoglycan cell wall, and no outer membrane. They stain very darkly (purple) in Gram stain.

Actinobacteria

Gram positive, high G+C content in DNA

Corynebacterium

Gram-positive bacillus - Diphtheria

Gardnerella

Gram-variable coccobacillus Colonize the human vagina, may alter the microbial ecology, thus leading to vaginosis

Mycobacterium

Gram-positive, Acid-fast bacillus - Tuberculosis

Actinomyces

Gram-positive bacillus - Decomposes organic matter and may cause gum disease in humans.

Bifidobacterium

Gram-positive, filamentous actinobacterium

Anaerobes commonly found in human gut microbiota

Frankia

Gram-positive, fungus-like (filamentous) bacillus Nitrogen-fixing bacteria; live in symbiosis with legumes

Propionibacterium

Gram-positive bacillus - contribute to acne

Streptomyces

Gram-positive, fungus-like (filamentous) bacillus. Used in the production of antibiotics.

Bacillus spp.

Large Gram-positive bacillus, endospore formers. Anthrax

Clostridium spp.

Gram-positive bacillus, all known species are pathogenic.

Staphylococcus spp.

Gram-positive cocci in clusters. Opportunistic pathogen that is often antibiotic resistant.

Streptococcus spp.

Gram-positive cocci in chains. Causes skin and throat infections and is pyogenic.

pyogenic

pus forming

Enterococcus

Gram-positive coccus forms pairs in culture. Found in human gut, may cause UTI

Lactobacillus

Gram-positive baccilus, ferments sugars into lactic acid, used as probiotics.

Mycoplasma

Gram-positive due to genome. Smallest bacteria, lacks a cell wall and causes walking pneumonia.

Deeply branching bacteria

new group has been added based on physiological, biochemical, and genetic features and are thought to be a very early evolutionary form of bacteria. Their habitat is hot, acidic, ultraviolet light exposed, and anaerobic (no O2)

Acetothermus paucivorans

· Deeply Branching Bacteria
· Gram-negative anaerobic
· Thermophile

LUCA

Last Universal Common Ancestor. The shared ancestor that multiple organisms diverged from

Deincoccus radiodurans

bacteria in meat that will not die from gamma radiation
"Conan the Bacterium"

Archaea

Domain of unicellular prokaryotes that have cell walls that do not contain peptidoglycan

psuedopeptidoglycan

a component of some cell walls of Archaea

Crenarchaeota (phylum)

One of the three major divisions of Archaea; includes acid-loving microorganisms.

Eukarchaeota (phylum)

Containing Methanogens and Halobacteria