Micro Test

staphylococci

taxonomic information Bergey's Manual of Systematic Bacteriology provides taxonomic information for the 27 phyla of prokaryotes.

Nocardia Nocardia can degrade a variety of pollutants such as detergents, benzene, and PCBs.

budding In the process of budding, small buds receive copies of the cell's genetic material and break off, becoming independent cells. The parental cell is preserved during the process.

diplococci

domain

nitrogen

thermophiles In addition to recombinant DNA applications, the heat-stable enzymes from thermophiles have industrial applications such as additives for laundry detergents.

They must live inside cells, where they have access to nutrients produced by those cells. Since rickettsias can metabolize amino acids and Krebs cycle intermediates, they are forced to live inside mammalian cells to obtain their nutrients.

Endospores are produced as resting stages of the bacterium that can survive inhospitable conditions.

Bacteria and archaea differ significantly in their rRNA sequences, but fungi and animals share some rRNA characteristics.

No; archaea are not pathogenic.

You could look for the presence of peptidoglycan.

raw milk

He wants to rule out the possibility of bovine tuberculosis. The symptoms of tuberculosis and brucellosis are similar. A positive test result would indicate exposure to Mycobacterium bovis, which would have to be confirmed by culture.

Both agents provide for good penetration of body tissues and reach therapeutic levels. A key point in treatment for infections of intracellular pathogens is penetration of the antibiotic into host cells and tissues where the organism resides.

Mutant and nonmutant strains will demonstrate the ability to transition through intestinal mucosa. The ability of Brucella to transition through intestinal mucosa does not depend on urease activity.

sequestering of organism within the endoplasmic reticulum The ability of the organism to survive and replicate within an intracellular environment is key to establishing a chronic infection within the host.

separation of daughter cells Depending on the species, the daughter cells may or may not separate at the conclusion of binary fission. It is this event, in part, that leads to some of the cell arrangements observed in prokaryotic species.

methanogens Because methanogens are obligate anaerobes that are very efficient in converting CO2, H2, and organic acids into methane gas, they play an important role in sewage treatment.

Agrobacterium

They lack peptidoglycan cell walls. Archaea were slow to be discovered because they do not cause any known human diseases.

Heterocysts shield the organism's nitrogen fixation enzymes from oxygen. Since the enzymes responsible for nitrogen fixation are sensitive to oxygen, some cyanobacteria sequester these enzymes in special thick-walled, nonphotosynthetic cells called heterocysts.

halophiles Because of their tolerance for high salt environments, halophilic archaea can easily contaminate foods such as sausages and salted fish.

presence of a functioning ribosome Despite their very small size, chlamydias are bacterial cells. They have the basic components of cells, including genetic material consisting of both DNA and RNA, a cytoplasmic membrane, and basic organelles such as ribosomes.

the bottom of a swamp Extremophiles can be thermophiles or halophiles, both of which can survive in extreme environments. Methanogens are more likely to be found at the bottom of a swamp.

Botox is injected into the muscles and is not absorbed into other parts of the body.

long chains of cells A characteristic arrangement of C. diphtheriae cells is V-shapes or palisades, not long chains.

Three basic shapes Coccus: spherical Bacillus: rod Spiral: spiral

spirilla: stiff or spirochetes: flexible

curved rods

cells that are intermediate in shape between cocci and bacilli

prokaryotes that vary in shape and size: star-shaped, triangular, rectangular

are produced by Gram-positve bacteria bacillus and clostridium

a defensive strategy against hostile or unfavorable conditions

is called sporulation, requires 8 to 10 hours and proceeds in 8 steps. Depending on the species, a cell forms endospores either centrally, subterminally (near one end), or terminally (at one end

Most common method of asexual reproduction: 1. Cell replicates its DNA; each DNA molecule is attached to the cytoplasmic membrane 2.Cell grows, and as the cytoplasmic membrane elongates, it moves the daughter molecule of the DNA apart 3. Cell forms a cross wall, invaginating the cytoplasmic membrane 4. Cross wall completely divides daughter cells. 5. Daughter cells may or may not separate. Parental cell disappears with formation of progeny.

Variation of binary fission Occurs in some gram-positive bacilli Only inner portion of cell wall is deposited across the diving cell. Thickening of new cross wall puts tension on outer cell wall holding two cells together. As tension increases, outer wall at weakest point breaks, snapping moment that tears utmost of the way around. Daughter cells still can hang together, held at an angle acting like a hinge.

tetrads

Corynebacterium

results in the disappearance of the parental cell

live in unusual habitats or generate unusual metabolic by-products

Korarchaeota

Mycobacterium

cyanobacteria

clostridia

They do not have cell walls.

Lactobacillus

Rhizobium

Agrobacterium

Bdellovibrio

They have diverse 16S rRNA sequences.

methanogens

myxobacteria

binary fission

gammaproteobacteria

They have heterocysts to perform nitrogen fixation.

Heterocysts allow the enzymes responsible for nitrogen fixation to be segregated from the oxygen that is a by-product of photosynthesis.

Chlamydias, along with the rickettsias, are known for their intracellular life cycle that is relatively unique among the bacteria. Clostridia are Gram-positive bacteria that are known for their endospore production.

Bacteriorhodopsins are not photosynthetic pigments; most phototrophic bacteria use pigments such as chlorophylls and bacteriochlorophylls in order to photosynthesize.

Streptomyces aids in recycling a variety of nutrients in the environment.

One vegetative cell gives rise to only one endospore, which then may germinate and produce one vegetative cell; for this reason, endospores are not considered to be reproductive structures.

Bergey's Manual is the most authoritative reference on prokaryotic systematics.

These anaerobic microbes can cause a variety of serious infections, including abdominal, pelvic, and blood infections.

Sulfur bacteria are so named because they produce sulfur from the oxidation of hydrogen sulfide, a process by which they derive electrons for CO2 reduction.

Mycoplasmas stain pink (Gram-negative) in the Gram stain because they have no cell wall; however, genetically they are most similar to Gram-positive bacteria.

Prosthecae are used for attachment and for increasing the surface area for absorption of nutrients.

1. cocci: spherical 2. rod-shaped: bacilli 3. spirals

Stiff: spirilla or Flexible: spirochetes

slightly curved rods

Intermediate to cocci and bacilli

Variable shape and sizes

are produced within vegetative cells of the gram-positive genera bacillus and clostridium. Depending on the species in which they are formed, the endospores may b terminal, subterminal or centrally located.

binary fission, snapping division (a type of binary fission), spore formation, and budding.

Long chains: Streptococci Pairs: diplococci Foursomes: tetrads Cuboidal packets: sarcinae Clusters: Staphlococci

singly, in pairs, in chains, or in palisade (folded) arrangement.

Microscopy provides only visual clues, and many bacteria share the same visual characteristics.

biochemical tests

is a series of paired statements, of which only one applies to the unknown in question. is a rapid and reliable method for identifying bacterial unknowns. relies heavily on biochemical tests.

to identify the bacterium responsible for a particular disease to identify an unknown bacterium in an environmental sample responsible for degrading an environmental pollutant to identify the bacteria responsible for fermenting a sugar in a particular food product