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.