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.