Micro ch 11 Exam 2

green bacteria

A group of anoxygenic phototrophs that are green or brownish in color.

Mycoplasmas are a particular concern in laboratories studying viruses and eukaryotic cell physiology. This is because the small bacteria can ___________

pass through the filters used to sterilize tissue culture media, so they easily contaminate the media and thereby compromise experimental results.

Bacillus and Clostridium species are the most common ___________; the position of the spore in the cell can help with ___________

Gram-positive rod-shaped bacteria that form endospores identification

Lactic acid bacteria can _____ be distinguished from other bacteria that grow because _________

They can be easily distinguished from other bacteria that grow in the presence of O2 because they lack the enzyme catalase

Most lactic acid bacteria can grow in __________, but they typically carry out _______

aerobic environments, but they typically only carry out fermentation.

Clostridium species, which are obligate __________

anaerobes,

Legionella pneumophila can cause______________

legionellosis, a respiratory disease, when inhaled in aerosolized droplets.

The human body also provides many anaerobic environments, such as in ______________

he intestinal tract. Even the skin and the oral cavity, which are routinely exposed to O2, have anaerobic

Mycoplasmas When grown on agar media, cells in the center of a colony grow ________ producing a ____________ Makes it look like ________

into the medium, producing a dense central area that gives the characteristically small colony a "fried egg" appearance

Gram-positive bacteria that produce lactic acid as a major end product of their fermentative metabolism make up a group called the ___________

lactic acid bacteria.

Treponema species are ______________

obligate anaerobes or microaerophiles that often inhabit the mouth and genital tract.

chemoorganoheterotrophs.

oxidize organic compounds such as glucose to obtain energy. Those that grow anaerobically often use sulfur or sulfate as a terminal electron acceptor.

Aerobic chemolithotrophs obtain energy by _______________

oxidizing reduced inorganic chemicals, using O2 as a terminal electron acceptor.

Three Borrelia species are ____________. Tramsmitted by ____________

pathogens, transmitted by arthropods such as ticks and lice.

Several genera that live in soil can form a _________ that allows them to survive the dry periods that occur in many soils.

resting stage

Bacteroides species are ___________

small, strictly anaerobic, Gram-negative rods and coccobacilli.

genus Mycoplasma are among the _______ forms of life, and their genomes are thought to be _________

smallest about the minimum size for encoding the essential functions for a free-living organism.

Agrobacterium

species are plant pathogens that cause tumor-like growths

Rhizobium

species form a mutually beneficial relationship with certain types of plants.

Members of the genera Treponema and Borrelia are _______________

spirochetes that typically inhabit body fluids and mucous membranes of humans and other animals.

anoxygenic phototrophs often store _______________

sulfur granules, which can later be used as a source of electrons for reducing power.

The genus Streptomyces includes more than 500 species of

Aerobic Gram-positive bacteria that resemble fungi in their pattern of growth.

Methanogens

Archaea that obtain energy by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor, thereby generating methane.

endoflagella

Characteristic structures of motility in spirochetes that cause the cells to move with a corkscrew-like motion; unlike typical flagella, they are contained within the periplasm.

diphtheroids

Club-shaped Gram-positive cells that resemble the typical microscopic morphology of Corynebacterium diphtheriae.

nitrogen fixation

Conversion of nitrogen gas to ammonia.

acid-fast

Describes an organism that retains the primary stain in the acid-fast staining procedure.

coliform

Facultative, non-spore-forming, Gram-negative rods that ferment lactose, producing acid and gas within 48 hours at 35°C; most reside in the intestine, so they are used as indicators of fecal pollution; also called total coliforms

anoxic

Lacking O2.

spirochetes

Long, helical bacteria that have a flexible cell wall and endoflagella.

Spirochetes

Long, helical bacteria that have flexible cell walls and endoflagella.

Bacillus species include both _______________

Obligate aerobes and facultative anaerobes

primary producers

Organisms that convert CO2 into organic compounds; by doing so, they sustain other life forms, including humans.

Ti (tumor-inducing) plasmid

Plasmid of Agrobacterium tumefaciens that allows the organism to cause tumors in plants; a derivative is used as a vector to introduce DNA into plants by genetic engineering.

lactic acid bacteria includes:

Streptococcus, Enterococcus, Lactococcus, Lactobacillus, and Leuconostoc.

Legionella species are common in __________, where they often live within __________

aquatic environments, where they often live within protozoa.

Bdellovibrio species (bdello, from the Greek word for "leech")

are highly motile Gram-negative curved rods that prey on E. coli and other Gram-negative bacteria

Agrobacterium species cause plant tumors by by ___________

attaching to wounded plant tissue, and then transferring a part of a plasmid to a plant cell; in A. tumefaciens the plasmid is called the Ti plasmid (for "tumor-inducing"). The transferred DNA encodes the ability to synthesize plant growth hormones, causing uncontrolled growth of the plant tissue and resulting in a tumor. The transferred DNA also encodes enzymes that direct the synthesis of an opine, an unusual amino acid derivative

many Bacteroides species can be killed by ________ making it difficult to ________

brief exposure to O2, so they are difficult to study.

Like other bacteria that aerobically respire, Staphylococcus species are ____________

catalase-positive.

chemoorganotrophs are

chemoorganoheterotrophs.

Bacteroides species, which make up about a third of the bacteria in human feces, play an important role in ___________

digestion

microenvironments. These are created via the ______________

localized depletion of O2 by aerobes.

Bacteroides species inhabit the ____________

mouth, intestinal tract, and genital tract of humans and other animals.

Neisseria species are common microbiota of animals including humans, growing on ________

mucous membranes.

Being able to convert nitrogen gas (N2) to ammonia, which can then be incorporated into cell material. This process, called __________ is an exclusive ability of ___________

nitrogen fixation prokaryotes.

Being bioluminescent (emitting light) plays an important role in the mutually beneficial relationship between some of these bacteria and fish/squid

plays an important role in the mutually beneficial relationship between some of these bacteria and specific types of fish and squid. For example, certain types of squid have a specialized organ within their ink sac that is colonized by the bioluminescent bacterium Aliivibrio (Vibrio) fischeri. The light produced by the bacterial cells in the organ is thought to serve as a type of camouflage, masking the squid's contrast against the light from above and any shadow it might otherwise cast.

When a Bdellovibrio cell attacks, it strikes its prey with such force that it ____________

propels the prey a short distance. The parasite then attaches to its host and rotates with a spinning motion. At the same time, it makes digestive enzymes that break down lipids and peptidoglycan, eventually forming a hole in the cell wall of the prey. This allows the parasitic bacterium to penetrate the peptidoglycan, lodging in the periplasm.

prosthecate bacteria. are a diverse group of Gram-negative bacteria that have projections called ___________

prosthecae,

Mycoplasmas can grow to _________ causing ___________, so contamination might not be noticed.

very high cloudiness

prosthecae,

xtensions of the cytoplasm and cell wall. These extensions provide increased surface area to facilitate absorption of nutrients. Some prosthecae allow the organisms to attach to solid surfaces.

Members of the genus Mycoplasma lack ___________, but have __________

a cell wall, but most have sterols in their membrane to provide strength and rigidity.

Bacteroides species are often responsible for _______________appendicitis and abdominal surgery.

abscesses and bloodstream infections that follow

fruiting body 2 Types

(1) In myxobacteria, a complex aggregate of cells, visible to the naked eye, produced when nutrients or water are depleted; (2) in fungi, a specialized spore-producing structure.

enterics

A common name for members of the family Enterobacteriaceae.

rhizobia

A group of Gram-negative nitrogen-fixing bacteria that form symbiotic relationships with leguminous plants such as clover and soybeans. are a group of Gram-negative rod-shaped bacteria that often fix nitrogen and form intimate relationships with legumes (plants that bear seeds in pods).

purple bacteria

A group of anoxygenic phototrophs that are red, orange, or purple in color.

Cyanobacteria

Gram-negative oxygenic phototrophs; genetically related to chloroplasts. are a diverse group of photosynthetic Gram-negative bacteria that inhabit a wide range of environments, including freshwater and marine habitats, soils, and the surfaces of rocks. Many are able to convert nitrogen gas (N2) to ammonia, which can then be incorporated into cell material. This process, called nitrogen fixation, is an exclusive ability of prokaryotes.

Azotobacter species are __________ Have a resting cell called ________ that can withstand __________

Gram-negative pleomorphic, rod-shaped bacteria that live in soil. They can form a type of resting cell called a cyst that can withstand drying and ultraviolet radiation but not high heat.

Agrobacterium species are

Gram-negative rod-shaped bacteria that have an unusual mechanism of gaining a competitive advantage in soil. They cause plant tumors, the outcome of their ability to genetically alter plants for their own benefit

Lactic Acid Bacteria

Gram-positive bacteria that generate lactic acid as a major end product of their fermentative metabolism.

lactic acid bacteria

Gram-positive bacteria that generate lactic acid as a major end product of their fermentative metabolism.

coryneforms

Gram-positive cells that are club-shaped and arranged to form V shapes and palisades; resemble the typical microscopic morphology of Corynebacterium species.

Certain bacteria are bioluminescent, meaning they __________

emit light

Of the various types of dormant cells, ________ are by far the most resistant to environmental extremes.

endospores

B. anthracis causes the disease anthrax, which can be acquired from contacting its ________________

endospores in soil or in animal hides or wool. Unfortunately, the spores have also been used as an agent of domestic bioterrorism.

Many types of anaerobic bacteria obtain energy by _______________

fermentation, producing ATP only by substrate-level phosphorylation.

Scientists are only beginning to understand the vast diversity of microbial life. Although well over a million species of prokaryotes are thought to exist, only a ________ have been described and classified.

fraction of them

anaerobic habitats are still common. Mud and tightly packed soil limit the diffusion of ____________This creates anaerobic conditions just below the surface.

gases, and any O2 that penetrates is quickly converted to water by aerobically respiring organisms.

Some bacteria store phosphate, and others store compounds that can be used to ________

generate ATP

There are many variations of fermentation, using different organic energy sources and producing characteristic end products, but one example is:

glucose (energy source)→pyruvate(terminal electronacceptor)→lactic acid

A number of aquatic bacteria form _______ that store nutrients.

granules

Aquatic environments may also become anaerobic if they contain _____________This is evident in polluted lakes, where fish may die because of a lack of dissolved O2.

nutrients that promote the rapid growth of O2-consuming microbes.

Obligate aerobes obtain energy using

respiration exclusively; none of them can ferment.

Myxobacteria

Gram-negative bacteria that form complex multicellular structures called fruiting bodies.

myxobacteria

Gram-negative bacteria that group together to form complex multicellular structures called fruiting bodies

Prosthecate Bacteria

Gram-negative bacteria that have extensions projecting from the cells, thereby increasing their surface area.

prosthecate bacteria

Gram-negative bacteria that have extensions projecting from the cells, thereby increasing their surface area.

Sulfur-Oxidizing Bacteria

Gram-negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, generating sulfuric acid.

sulfur-oxidizing bacteria

Gram-negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, generating sulfuric acid.

Nitrifiers

Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite.

Neisseria species are ______________

Gram-negative bacteria, typically kidney-bean-shaped cocci in pairs.

Legionella species are ____________

Gram-negative obligate aerobes that use amino acids, but not carbohydrates, as a source of carbon and energy.

Staphylococcus species are ___________

Gram-positive cocci that are facultative anaerobes.

Nitrifiers

Group of Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrate.

obligate intracellular parasites

Organisms that grow only inside living cells.

Chemolithotrophs

Organisms that harvest energy by oxidizing inorganic chemicals.

Chemoorganotrophs

Organisms that harvest energy by oxidizing organic chemicals. Cyanobacteria Gram-negative oxygenic phototrophs; genetically related to chloroplasts.

chemotrophs

Organisms that obtain energy by oxidizing chemical compounds.

Chemoorganotrophs

Organisms that obtain energy by oxidizing organic compounds such as glucose;

anoxygenic phototrophs

Photosynthetic organisms that do not produce O2.

Oxygenic Phototrophs

Photosynthetic organisms that produce O2.

oxygenic phototrophs

Photosynthetic organisms that produce O2.

Anoxygenic

Phototrophs Photosynthetic organisms that do not produce O2.

ecophysiology

The study of the physiological mechanisms organisms use to thrive in a given environment.