Microbiology Chapter 11

Haemophilus influenzae is a virus that causes the "flu."

False- it causes ear infections, respiratory infections, meningitis

Which of the following statements about Thiomargarita namibiensis are TRUE?

It stores sulfur, its energy source. It stores nitrate, its terminal electron acceptor. Its name means "sulfur pearl of Namibia."

Select the TRUE statements about obligate aerobes.

Micrococcus species typically form colored colonies, making them easy to identify. Mycobacterium species have an unusual cell wall that requires special procedures for staining.

Bacteria in aquatic environments have evolved various mechanisms to maximize nutrient uptake and retention. Why?

Most aquatic environments lack a steady supply of nutrients.

Which of the following about hydrothermal vents is FALSE?

Photosynthesis supports food production in the region.

The role of sulfur in the metabolism of Thiomargarita namibiensis is similar to which of the following in human metabolism?

Sugar

Which of the following bacteria can oxidize metal compounds exposed during strip mining of coal, dramatically lowering pH and leading to damaging acid run-off into the surrounding ecosystem?

Sulfur-oxidizing bacteria

Nitrogen-fixing cyanobacteria are critically important ecologically.

True

Staphylococcus species can be distinguished from Streptococcus, Enterococcus, and Lactococcus species on the basis of catalase activity.

True

The rhizobia group of microbes

form a nodule that creates an endosymbiotic relationship between legume plants and the bacterial cells.

Thioploca species build sheaths in which they "commute" from the aquatic sediments to the water above. Their reason for leaving sediments is to

obtain nitrite, which they use as a terminal electron acceptor.

Methanogens are a group of archaea that generate ATP by

oxidizing hydrogen gas, using carbon dioxide as a terminal electron acceptor.

Select the TRUE statement regarding Agrobacterium species.

They stimulate tumor-like growths in plants to obtain nutrients.

Which of the following is NOT an obligate intracellular parasite?

Treponema pallidum

All coliforms are Enterobacteriaceae, but not all Enterobacteriaceae are coliforms.

True

Select the FALSE statement regarding bacterial diversity.

During unfavorable conditions, myxobacteria travel as a pack to a new location.

The main difference between purple sulfur bacteria and purple non-sulfur bacteria is that purple sulfur bacteria prefer to use organic molecules rather than hydrogen sulfide to generate reducing power.

False- it is the purple non-sulfur bacteria that prefer to use a variety of organic molecules rather than hydrogen sulfide to generate reducing power. The purple sulfur bacteria use hydrogen sulfide.

Members of this group of microbes can break down glycogen deposited in the vaginal lining in response to estrogen. This helps to drop the pH in the area, preventing infections.

Lactic acid bacteria

Which of the statements about chemotrophs is FALSE?

Lactic acid bacteria such as Lactobacillus obtain their ATP by oxidizing glucose, using lactic acid as their terminal electron acceptor.

Which of the following organisms is NOT classified as a facultative anaerobe?

Psuedomonas auruginosa

Which of the following are TRUE regarding coliforms?

They are faculative aerobes They are Gram-negative They belong to the Enterobacteriaceae They characteristically ferment lactose They are used as indicators of fecal pollution

Select the TRUE statements about nitrifiers.

They convert nitrite to nitrate They convert ammonium to nitrite

Which of the following statements about members of the genus Mycoplasma are true?

They lack a peptidoglycan cell wall They are difficult to filter from growth media They are unaffected by penicillins

Only Gram-positive bacteria can form resting stage structures.

False

Identify which of the following are characteristics of cyanobacteria.

Gram-negative Oxygenic phototrophs May possess nitrogenase, an enzyme that fixes N2 into organic compounds Some species may form filamentous multicellular associations

While purple bacteria conduct anoxygenic photosynthesis, green sulfur bacteria produce oxygen during their photosynthetic process, making them oxygenic phototrophs.

False

1. Clostridium difficile 2. Clostridium perfringens 3. Clostridium tetani 4. Clostridium botulinum

1. Antibiotic-associated diarrheal disease. 2. Gas gangrene: a disease characterized by necrotic tissue and the production of gas. 3. Tetanus: a disease characterized by painful muscle spasms. 4. Botulism, a disease characterized by flaccid paralysis.

1. Methanogens 2. Lactic acid bacteria 3. Clostridium species 4. Sulfur and sulfate-reducing bacteria 5. Propionibacterium species

1. Archaea, live in anaerobic environments with H2 and CO2. 2. Gram-positive, catalase-negative, grow in aerobic environments but only ferment, producing acidic conditions. 3. Generally in endospore form in soil, but will germinate to vegetative form when anaerobic conditions arise. Gram-positive rods. 4. Found in mud with organic material and oxidized sulfur compounds. 5. Gram-positive pleomorphic (irregular shaped) rods, fermenters, often used in Swiss cheese production.

A unicellular microorganism was recovered from a hot spring (95°C) in Wyoming. After observation, it was determined that the cells lacked a nucleus, had a cell wall that lacking peptidoglycan, and had 70S ribosomes. Analysis of the cytoplasmic membrane revealed lipids containing long-chained branched hydrocarbons with ether linkages. Determine how this organism would be classified, based on the description provided.

Archaea

Extreme halophiles/extreme thermophiles are members of the domain ______.

Archaea

Review the differences between archaea and bacteria by completing each sentence.

Archaea are prokaryotic organisms recently classified as belonging to their own domain. Although they share many characteristics with bacteria, members of the Domain Archaea are more closely related to Domain Eukarya than to bacteria. The ribosomal and protein sequences of archaea are more closely related to those of eukaryotes than those of bacteria. Characteristics that define archaea, however, include the presence of unique membrane lipids, cell wall construction and composition, and metabolic pathways. Adaptations to their metabolic pathways allow archaea to live in extreme environments, such as areas with high levels of salt (halophiles) or high temperatures (thermophiles).

Based on what you know about the myxobacteria, for which of the following could they serve as an experimental model?

Cell-to-cell communcation and cooperation

Identify which of the following genera have members that are disease-causing facultative anaerobes.

Corynebacterium Escherichia Pseudomonas

Which of the following is NOT a member of the Enterobacteriaceae family (Gram-negative rods, glucose fermenters, some members motile with peritrichous flagella, some members lactose fermenting)?

Corynebacterium diphtheriae

The purple bacteria are Gram-negative organisms that undergo ______ photosynthesis by using hydrogen sulfide or organic molecules as an electron source, rather than water.

anoxygenic

Corynebacterium species and Enterobacteriaceae family members are examples of ______ anaerobes, meaning that they preferentially use aerobic respiration if O2 is available, but can ferment if it is not.

facultative

1. Some Photobacterium and Vibrio species 2. Epulopiscium species 3. Bdellovibrio species 4.Legionella species

1. Form an endosymbiotic relationship with certain types of fish and squid. The animals provide nutrients to the bacteria, and the bacteria provide bioluminescence that can be used as camouflage against predation. 2. Gram-positive, cigar-shaped bacteria that reside in the intestinal tract of surgeonfish in order to obtain nutrients. Very large (for bacteria), with the unusual trait of possessing thousands of copies of the bacterial genome within the cell. 3. Highly motile Gram-negative curved rods that prey on E. coli and other Gram-negative bacteria. The attacker forms a hole in the cell wall of the target, enters, and consumes the cellular constituents of the target. 4. Often reside in protozoa. They are Gram-negative obligate aerobes that utilize amino acids from the eukaryotic host, but not carbohydrates, as a source of carbon and energy.

Which of the statements is FALSE?

Rhizobia transfer some of their DNA to the host plant.

Which of the following about bacterial diversity are FALSE?

Squid and flashlight fish have specialized organs that carry nitrogen-fixing bacteria Agrobacterium pecies carry plasmids with genes for a toxin that destroys plant cells

Which of the following statements regarding the Enterobacteriaceae are TRUE?

They are Gram-negative rods that form part of the normal microbiota. Their name derives from the fact that they reside in intestinal tracts of humans and animals They are facultative anaerobes that ferment glucose. Enterobacteriaceae called coliforms ferment lactose.

Cyanobacteria have evolved elaborate mechanisms for preventing O2 from coming into contact with the nitrogenase enzyme. Why?

Nitrogenase enzyme complexes are damaged or destroyed by O2.

Members of the genus Mycoplasma have no cell wall, making them somewhat unique in the microbial world. How do they prevent osmotic lysis?

Their cytoplasmic membrane is rich in sterols to help provide added strength and rigidity.

Which of the following are TRUE regarding purple sulfur bacteria, purple non-sulfur bacteria, and green sulfur bacteria?

They are anoxygenic phototrophs. They all use sunlight as an energy source.

Nitrogen-fixing cyanbacteria are important because

they can incorporate N2 into organic material, thus generating a form that other organisms can use. they can incorporate CO2 into organic material, thus generating a form that other organisms can use. they help to limit CO2 buildup in the atmosphere, by using this gas as a carbon source.

1. Sulfur-oxidizing bacteria 2. Hydrogen-oxidizing bacteria 3. Nitrifying bacteria

1. Gram-negative rods/spirals, may form filaments, obtain energy by oxidizing hydrogen sulfide and thiosulfate with O2 as a terminal electron acceptor. 2. Gram-negative obligate chemolithotrophs, use H2 as an energy source with O2 as a terminal electron acceptor. 3. Gram-negative bacteria that obtain energy by oxidizing inorganic compounds like ammonia.

1. Micrococcus species 2. Pseudomonas species 3. Thermus species 4. Deinococcus species 5. Mycobacterium species

1. Gram-positive cocci found in soil, dust particles, inanimate objects, skin; tolerates dry and moderately salty conditions. 2. Gram-negative rods with polar flagella. Often produce pigments. Widespread in soil and water. Most are harmless, but some can be opportunistic pathogens of humans. 3. Stain Gram-negative, but have an unusual cell wall. Survive well in high heat, due to their interesting heat-resistant enzymes. 4. Stain Gram-positive, with an odd multilayer cell wall that lets the cells resist high levels of gamma radiation (also due to their extensive DNA repair enzyme activities). 5.Generally pleomorphic (variable shape) rods that stain poorly and resist destaining due to waxy lipids in their cell wall structure. Several species cause human diseases.

1. Thermophilic extreme acidophiles 2. Sulfur-reducing hyperthermophiles 3. Sulfur oxidizers 4. Nanoarchaea 5. Methane-generating hyperthermophiles

1. Members grow optimally at or below pH 2. One was originally isolated from a coal waste pile. Two others were isolated inhabiting acidic areas in regions that spew sulfurous gases. 2. Obligate anaerobes that use sulfur as a terminal electron acceptor, generating H2S. Often isolated from hot sulfur-containing environments such as sulfur hot springs and hydrothermal vents. Some even have possible growth temperatures above 100°C. 3. Obligate aerobes that use O2 as a terminal electron acceptor, generating sulfuric acid. Only grow above 50°C and at a pH between 1 and 6. 4. Grows as 400 nm spheres attached to the surface of - and most likely parasitizing - the Ignicoccus species. 5. Oxidize H2, using CO2 as a terminal electron acceptor to yield gas. Can grow in temperatures as high as 97°C.

Select which of the following statements about Agrobacterium tumefaciens is FALSE.

A. tumefaciens causes a plant disease called "root gall" that is characterized by swollen nodules on the roots of plants.