BSC 160 - Chapter 11
sheath
A ____ plays a protective role in aquatic bacteria, helping them attach to solid objects in favorable habitats while sheltering them from attack by predators.
granules
A number of aquatic bacteria form ____ that store nutrients.
Clostridium
As a group, ____ species ferment a wide variety of compounds, including sugars and cellulose.
mucous membranes
Bacteroides, Bifidobacterium, Bordetella, Campylobacter,Heliocobacter, Haemophilus, Neisseria, Treponema, and Borrelia are genera that inhabit ____ ____
obligate intracellular parasites
Cannot reproduce outside a host cell: host cells supply compounds they would otherwise need to synthesize. Most have lost ability to synthesize needed substances. Multiple bacterial examples; all are tiny Gram-negative rods or coccobacilli.
endospores
Clostridial ____ can tolerate O2 and survive for long periods by withstanding levels of heat, drying, chemicals, and irradiation that would kill vegetative bacteria.
morphologically
Cyanobacteria are ____ diverse.
gas vesicles
Cyanobacteria that live in aquatic environments often have ____ ____, allowing them to move vertically within the water column.
coliforms
Enteric bacteria that characteristically ferment lactose are included in a group called ____.
methanogens
Environments where ____ are commonly found include swamps, marine sediments, rice paddies, and the digestive tracts of humans and other animals.
halophiles
Extreme ____ are found in salt lakes, soda lakes, and brines. Most grow well in saturated salt solutions.
Vibrio
Facultative anaerobes. Typically found in marine environments because most species require at least low levels of Na+ for growth. Gram-negative.
sulfur-oxidizing bacteria
Gram-negative bacteria that obtain energy by oxidizing elemental sulfur and reduced sulfur compounds, generating sulfuric acid
hydrogen-oxidizing bacteria
Gram-negative bacteria that obtain energy by oxidizing hydrogen
nitrifiers
Gram-negative bacteria that obtain energy by oxidizing inorganic nitrogen compounds such as ammonium or nitrite
Azotobacter
Gram-negative pleomorphic, rod-shaped bacteria that live in soil. Can form a type of resting cell called a cyst. Have negligible metabolic activity. Can withstand drying and ultraviolet radiation but not high heat. Can fix nitrogen in aerobic environments.
Agrobacterium
Gram-negative rod-shaped bacteria that have an unusual mechanism of gaining a competitive advantage in soil; can cause plant tumors
cyanobacteria
In addition to being photosynthetic, many ____ are able to convert nitrogen gas (N2) to ammonia, which can then be incorporated into cell material.
catalase
Lactic acid bacteria can be easily distinguished from other bacteria that grow in the presence of O2 because they lack the enzyme ____.
fermentation
Many types of anaerobic bacteria obtain energy by ____, producing ATP only by substrate-level phosphorylation.
glucose
Members of the Enterobacteriaceae are facultative anaerobes that ferment ____ and, if motile, generally have peritrichous flagella.
Pseudomonas
Obligate aerobes. Common environmental bacteria that, as a group, can degrade a wide variety of compounds. Gram-negative.
Deinococcus
Obligate aerobes. Resistant to the damaging effects of gamma radiation. Stains Gram-positive.
Thermus
Obligate aerobes. Source of Taq polymerase (used in PCR). Produce heat-stable enzymes. Unusual cell wall. Stain Gram-negative.
Mycobacterium
Obligate aerobes. Waxy cell wall resists staining. Acid-fast.
Micrococcus
Obligate aerobes. Widely distributed. Common laboratory contaminants. Gram-positive.
obligate intracellular parasites
Rickettsia, Orientia, Ehrlichia, Coxiella, Chlamydia, Chlamydophila, and Wolbachia are genera that are ____ ____ ____.
resting stage
Several genera that live in soil can form a ____ ____ that allows them to survive the dry periods that occur in many soils.
nutrients
Some aquatic bacteria obtain ____ directly from other organisms.
organic, sulfur
Sulfate- and sulfur-reducing bacteria generally live in mud that has ____ material and oxidized ____ compounds.
prosthecate
The ____ bacteria are a diverse group of aquatic Gram-negative bacteria that have projections called prosthecae, which are extensions of the cytoplasm and cell wall.
obligate aerobes
____ ____ obtain energy using respiration exclusively; none of them can ferment.
mucous membranes
____ ____ of the respiratory, genitourinary, and intestinal tracts provide a habitat for numerous kinds of bacteria.
facultative anaerobes
____ ____ preferentially use aerobic respiration if O2 is available. As an alternative, however, they can ferment.
Bacillus, Clostridium
____ and ____ species are the most common Gram-positive rod-shaped bacteria that form endospores.
Magnetotactic
____ bacteria contain a string of magnetic crystals that align cells with the Earth's magnetism. This allows them to move up or down in the water or sediments.
Myxobacteria
aerobic Gram-negative bacteria that group together to form complex multicellular structures called fruiting bodies; have a unique developmental cycle as well as a resting stage
methanogens
archaea that obtain energy by oxidizing hydrogen gas, using CO2 as a terminal electron acceptor, thereby generating methane
lactic acid bacteria
includes members of the genera Streptococcus, Enterococcus, Lactococcus, Lactobacillus, and Leuconostoc
spirochetes
long helical bacteria that have flexible cell walls and endoflagella
sheathed
____ bacteria form chains of cells encased within a tube, or sheath.
methanogens
____ generate methane when they oxidize hydrogen gas as an energy source, using CO2 as a terminal electron acceptor.
prosthecae
____ provide increased surface area to facilitate absorption of nutrients in aquatic bacteria. Some allow the organisms to attach to solid surfaces.
Staphylococcus
____ species are Gram-positive cocci that are facultative anaerobes. Most reside harmlessly as part of the normal microbiota of the skin. They are catalase-positive.
Clostridium
Members of the genus are Gram-positive rods that can form endospores. They are common soil inhabitants, and the vegetative cells live in the anaerobic microenvironments created when aerobic organisms consume available O2.
anaerobic
Methanogens are found in ____ environments where H2 and CO2 are both available.
aerobic, fermentation
Most lactic acid bacteria can grow in ____ environments, but they typically only carry out ____.
Propionibacterium
____ species are Gram-positive pleomorphic (irregular-shaped) rods that produce propionic acid as their primary fermentation end product. They can also ferment lactic acid, and so can extract energy from a waste product of other bacteria.
Propionibacterium
____ species are valuable to the dairy industry because their fermentation end products are important in Swiss cheese production.
cyanobacteria
diverse group of Gram-negative oxygenic phototrophs; genetically related to chloroplasts
lactic acid bacteria
gram-positive bacteria that generate lactic acid as a major end product of their fermentative metabolism
Rhizobia
group of Gram-negative rod-shaped bacteria that often fix nitrogen and form intimate relationships with legumes; live within cells in nodules formed on the roots of the plants; synthesize the protein leghemoglobin
anaerobic chemolithotrophs
organisms that harvest energy by oxidizing inorganic chemicals; cannot use O2 as a terminal electron acceptor and instead must use an alternative such as carbon dioxide or sulfur
anaerobic chemoorganotrophs
organisms that harvest energy by oxidizing organic chemicals; often use sulfur or sulfate as a terminal electron acceptor
thermophiles
Extreme ____ are found near hydrothermal vents and in hot springs; some grow at temperatures above 100°C. Includes examples of methane-generating, sulfur-reducing, and sulfur-oxidizing archaea, as well as extreme acidophiles.
Corynebacterium
Facultative anaerobes. Widespread in nature. Gram-positive.
Enterobacteriaceae
Family of facultative anaerobes. Most reside in the intestinal tract. Those that ferment lactose are coliforms. Their presence in water serves as an indicator of fecal pollution. Gram-negative.
Streptomyces
Form a mycelium (a visible mass of branching filaments) and a resting stage. Produce a variety of extracellular enzymes that allow them to degrade various organic compounds. Naturally produce a wide array of medically useful antibiotics, including streptomycin, tetracycline, and erythromycin.