Microbiology Ch 11

species of green sulfur bacteria

Chlorobium, Pelodictyon

species of purple sulfur bacteria

Chromatium, Thiospirillium, Thiodictyon

Sulfur- and sulfate-reducing bacteria

anaerobic chemoorganotrophs - anaerobic respiration - use sulfate as terminal acceptor, generating hydrogen sulfide. Found in anaerobic mds rich in organic material. Gram-negative. ex: Desulfovibrio

Propionibacterium

anaerobic chemoorganotrophs - pleomorphic (irregular-shaped) rods, obligate anaerobes that produce propionic acid as their primary fermentation end product. Used in the production of Swiss cheese. Gram-positive

lactic acid bacteria

anaerobic chemoorganotrophs - produce lactic acid as the major end product of their fermentative metabolism. Aerotolerant anaerobes. Several genera are used by the food industry. Gram-positive

purple non-sulfur bacteria

anoxygenic phototroph - grow in aquatic habitats, preferentially use organic compounds as a source of electrons for reducing power. Many are metabolically versatile. May store sulfur; granules form outside cell. Gram-negative

Hyphomicrobium

divides by budding; daughter cell detaches and moves to a new location

Clostridium

endospore-forming, rod-shaped, obligate anaerobes. Germinate when conditions improve. Inhabitants of soil. Some cause diseases. Gram-positive

Corynebacterium

facultative anaerobe - Gram-positive pleomorphic rods, club-shaped; some are strict aerobes.

primary producers

harvest the energy of sunlight, using it to convert CO2 into organic compounds

Bdellovibrio

highly motile Gram-negative curved rods that prey on other bacteria; attaches to prey and rotates with spinning motion, makes digestive enzymes that break down lipids and peptidoglycan, forms hole in cell wall, lodges into periplasm

anoxygenic phototrophs

likely earliest photosynthesizers, do not produce O2 as result of photosynthesis, use unique bacteriochlorophyll, oxidize hydrogen sulfide or organic molecules to make NADPH, Gram-negative rods

Caulobacter

model for research on cellular differentiation; single polar pros theca (stalk)

Pseudomonas

obligate aerobe; Gram-negative rods with polar flagella and often produce pigments. Some can grown anaerobically if nitrate is available as a terminal electron acceptor

Mycobacterium

obligate aerobe; waxy cell wall resists staining; acid-fast; pleomorphic rods, can be harmless or pathogenic

Anaerobic Chemolithotrophs

obtain energy by oxidizing inorganic chemicals, such as hydrogen gas in the absence of oxygen

Aerobic chemolithotrophs

obtain energy by oxidizing reduced inorganic chemicals, using O2 as a terminal electron acceptor

Green sulfur bacteria

Anoxygenic phototroph - found in habitats similar to purple sulfur bacteria. Form granules outside of cell, lack flagella. Gram-negative

Hydrogen-oxidizing bacteria

aerobic chemolithotrophs - thermophilic bacteria that oxidize hydrogen gas as an energy source. Usually live in hot springs. Gram negative. Ex: Aquifex, Hydrogenabacter

Facultative anaerobes

aerobic chemoorganotrophs - preferentially use aerobic respiration if oxygen is available; as an alternative they can ferment

Anaerobic Chemoorganotrophs - Fermentation

anaerobic bacteria that obtain energy by fermentation, producing ATP only by substrate-level phosphorylation

purple sulfur bacteria

anoxygenic phototroph - form colored masses in sulfur-rich aquatic habitats and use sulfur compounds as a source of electrons when making reducing power. Most store sulfur in intracellular granules. Gram-negative

Bioluminescent bacteria - Aliivibrio fischeri, Vibrio harveyi, Photobacterium phosphoreum

bacteria that emit light; typically inhabit marine environments, Gram-negative, straight or curved rods; facultative anaerobes

filamentous anoxygenic photographic bacteria

characterized by their filamentous growth, exhibit gliding motility, metabolically diverse. ex: Chloroflexus

coliforms

enteric bacteria that characteristically ferment lactose

Vibrio

facultative anaerobe - typically found in marine environments because most species require at least low levels of Na+ for growth. Gram-negative straight or slightly curved rods

Thermus

obligate aerobe; Gram-negative, unusual cell wall, thermophilic.

Micrococcus

obligate aerobe; Gram-positive cocci found in soil and on dust particles, inanimate objects, and skin. Typically pigmented. Can grow in dry and salty environments

Deinococcus

obligate aerobe; Gram-positive; unusual cell wall w/ multiple layers; resistant to the damaging effects of gamma radiation

Chemolithotrophs

obtain energy by oxidizing inorganic chemicals, such as hydrogen gas (most are members of Archaea)

Chemotrophs

organisms that harvest energy by oxidizing chemicals

Anaerobic Chemoorganotrophs - Anaerobic Respiration

oxidize organic compounds such as glucose to obtain energy, often use sulfur or sulfate as a terminal electron acceptor

Bacillus and Clostridum

the most common Gram-positive rod-shaped bacteria that form endospores; the position of the spore in the cell can help in identification

Aerobic chemoorganotrophs

oxidize organic compounds to obtain energy, using oxygen as a terminal electron acceptor

Sulfur-oxidizing, nitrate-reducing marine bacteria - Thioploca, Thiomargarita

bacteria that form storage granules; use novel mechanisms to compensate for the face that their energy source (reduced sulfur compounds) and terminal electron acceptor (nitrate) do not coexist

oxygenic phototrophs - cyanobacteria

photosynthetic organisms that use water as a source of electrons for reducing power, some fix N2. Inhabit freshwater and marine habitats, soils, and the surface of rocks. Gram-negative. ex: Anabaena, Synechococcus

Methanogens

- a group of Archaea that generate ATP by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor (this process generates methane) - Methanospirillum, Methanosarcina - anaerobic chemolithotroph

Free-living spirochetes - Spirochaeta, Leptospira

Gram-negative long spiral-shaped bacteria that move by means of endoflagella; allows them to move through thick, viscous environments

Legionella

Gram-negative obligate aerobes that use amino acids, but not carbohydrates, as a source of carbon and energy; aquatic environments; often live within protozoa

Azotobacter

Gram-negative pleomorphic, rod-shaped bacteria that live in soil. Can form a type of a resting cell called a cyst. Can fix nitrogen in aerobic conditions

Rhizobia

Gram-negative rod-shaped bacteria that fix nitrogen; form symbiotic relationship with legumes

Agrobacterium

Gram-negative rods, cause plant tumors. Scientists use their Ti plasmid to genetically modify plants

Spirillium

Gram-negative spiral-shaped, microaerophilic bacteria.

Streptomyces

Gram-positive rod, resemble fungi in their pattern of growth; produce antibiotics; dormant spores called conidia.

Epulopiscium

Very large cigar-shaped bacteria that multiply by releasing several daughter cells; each cell has thousands of copies of the genome. Gram-positive

Myxobacteria

aerobic Gram-negative rod-shaped bacteria that group together to form complex multicellular structures called fruiting bodies; cells within these differentiate to form dormant microcysts. Ex: Chondromyces, Myxococcus, Stigmatella

sulfur-oxidizing bacteria

aerobic chemolithotrophs - obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, including hydrogen sulfide and thiosulfate. Gram-negative rods or spirals

Nitrifiers

aerobic chemolithotrophs - oxidize ammonia or nitrate as energy sources. This converts certain fertilizers to a form easily leached from soils, and depletes O2 in waters polluted with ammonia-containing wastes. Genera that oxidize nitrate prevent the toxic buildup of nitrate. Gram-negative

Filamentous sulfur oxidizers

aerobic chemolithotrophs - oxidize sulfur compounds as energy sources. Found in sulfur springs and sewage-polluted waters. Gram-negative. Ex: Beggiatoa, Thiothrix

Unicellular sulfur oxidizers

aerobic chemolithotrophs - oxidize sulfur compounds as energy sources. Some species produce enough acid to lower the pH to 1.0. Gram-negative. Ex: Thiobacillus, Acidithiobacillus

Members of the family of Entereobacteriaceae

Escherichia, Enterobacter, Klebsiella, Proteus, Salmonella, Shigella, Yersinio

species of purple non-sulfur bacteria

Rhodobacter, Rhodopseudomonas

species of lactic acid bacteria

Streptococcus, Enterococcus, Lactococcus, Lactobacillus, Leuconostoc

The Enterobacteriaceae Family

facultative anaerobes - Gram-negative rods; most reside in intestinal tract of humans and other animals, some thrive in rich soil

anoxic

without oxygen

Ti plasmid

A plasmid of a tumor-inducing bacterium that integrates a segment of its DNA into the host chromosome of a plant; frequently used as a carrier for genetic engineering in plants.

Prosthecate bacteria - Caulobacter, Hyphomicrobium

Gram-negative bacteria that have projections called prosthecae; provide increased surface area to facilitate absorption of nutrients

Sheathed bacteria - Sphaerotilus, Leptothrix

Form chains of cells enclosed within a tube or sheath. Spread by swarmer cells. Gram-negative

Aerobic chemoorganotrophs - obligate aerobes

Micrococcus, Mycobacterium, Pseudomonas, Thermus, Deinococcus

acid-fast bacteria

Mycobacterium and Nocardia

species of Nitrifiers

Nitrosomonas, Nitrosococcus, Nitrobacter, Nitrococcus

anaerobic respiration

Respiration in the absence of oxygen. This produces lactic acid.