Lecture 14 - Smartbook

An anoxic atmosphere lacks ___.

oxygen

What are some lethal members of the Family Enterobacteriaceae?

p. 290

Members of the genus Corynebacterium are Gram-positive rods that exhibit a variety of shapes. THis difference in shape is referred to as being ___.

pleomorphic

Autotrophs that convert CO2 into organic materials are ___ ___.

primary producers

Anaerobics chemoorganotrophs _____ (AND) _____.

produce ATP via substrate level phosphorylation (AND) can obtain energy via fermentation.

Micrococcus species are (___ tolerant) + (___ pigmented) + (obligate ___) + (tolerant of ___ conditions)

(SALT tolerant) + (TYPICALLY pigmented) + (obligate AEROBES) + (tolerant of DRY conditions)

In terms of morphology _____ + _____ + _____.

can form filamentous multicellular associations + can be cocci, rods, or spiral shaped + can be unicellular.

An organism that harvests energy by oxidizing inorganic chemicals, but not organic chemicls, is a ____.

chemolithotroph

Cyanobacteria have photosystems that function very similarly to those found in _____.

chloroplasts

Phosphorus is not a component of ___.

proteins

Filaments of the Begglatoa species exhibit ___ motility, a mechanism that does not require flagella.

gliding

An organism that requires a minimum of 9? NaCl would be called an extreme ___.

halophile

Why do Mycobacterium stain poorly?

Because of the waxy lipids (mycolic acids) in their unusual cell wall.

Mycobacterium species stain poorly because their cell walls contain ___.

Mycolic acids

_____ are fungi growing in symbiotic relationship with plant roots.

Mycorrhizas

During aerobic respiration, microbes use ___ as their terminal electron acceptor.

O2

Facultative anaerobes preferentially use aerobic respiration if ___ is present.

O2

Members of the ___, a diverse group of genera that includes Rhizobium, Bradyrhizobium, Sinorhizobium, and Azorhizobium, are bacteria identified as the most agriculturally important symbiotic nitrogen-fixers.

Rhizobia

Sulfur-reducing bacteria have a positive impact on the environment because they _____.

are an essential component of the sulfur cycle

The weight of all organisms present in an ecosystem is the ___.

biomass

Because energy is lost as ___ when chemical bonds are broken, energy is continually lost from biological systems.

heat

An important trait of species of the thermophilic Thermus is there ___-___ ___.

heat-stable enzymes.

Deinococcus species have the ability to withstand ___ ___ of ___.

high doses of radiation

Members of the Gram-negative genera Aquifex and Hydrogenobacter are hydrogen-oxidizing bacteria. An example of their metabolism involves using _____.

hydrogen as a source of electrons and oxygen as a terminal electron acceptor, forming water ex: H2 + 1.5 O2 --> H2O

In a healthy individual, anaerobes can regularly be found on and in the ___ ___, ___ ___, and ___.

oral cavity, intestinal tract, skin

The purple bacteria are Gram-negative organisms that can appear ___ due to their light-harvesting pigments.

orange, red, or purple

Chemoorganotrophs oxidize ___ compounds such as glucose to obtain energy.

organic

Chemoorganotrophs use reduced ___ compounds such as sugars, lipids, and amino acids as energy sources.

organic

Pseudomonas species are Gram-negative rods that, unlike members of the family Enterobacteriaceae, are _____.

oxidase-positive non-fermenters

Anoxygenic phototrophs typically live in which of the following environments?

bogs, lakes, upper layers of mud (have adequate light but little or no O2)

The ___ produced by the genus Clostridium have the ability to survive harsh environmental conditions chat can commonly kill the vegetative bacterial cells.

endospores

Most plants and microorganisms assimilate sulfur as ___, reducing it and then incorporating the reduced from into biomass.

sulfate

Methanogens are organisms that (generate ___) + (use ___ as a terminal electron acceptor) + (obtain energy by oxidizing ___ gas).

generate methane + use CO2 as a terminal electron acceptor + obtain energy by oxidizing hydrogen gas.

Name the genera of organisms by their description. D1. Common members of the microbiota in the mouth and the vagina during childbearing years D2. Members typically inhabit the intestinal tract D3. Includes species used to make cheese

D1. Lactobacillus D2. Enterococcus D3. Lactococcus

___ are formed by fungi growing around plant cells and forming a sheath around the roots.

Ectomycorrhizas

Sulfur-oxidizing prokaryotes oxidize ___ (AND) ___ to sulfate?

H2S (AND) S0

What can you say about Pseudomonas?

are Gram-negative rofds that have polar flagella and often produce pigments, most are strict aerobes, but some can grow anaerobically if nitrate is available as a T.E.A., the do not ferment, are oxidase-positive. Distinguishes them from members of the family Enterobacteriaceae (e.g., E. coli)

The earliest oxygenic phototrophs probably belonged to a group of bacteria called the _____.

cyanobacteria

Nitrogen is a significant component of which of the following macromolecules?

proteins and nucleic acids

Obligate aerobes obtain energy using ___ ___.

respiration only.

Some cyanobacteria have negative effects, such as producing ____, ____.

toxins that can harm animals, geosmin, which can influence the taste of drinking water

Members of the filamentous bacterial species Anabaena protect the nitrogenase enzyme from O2 by _____.

restricting the process of nitrogen fixation to heterocysts where O2 is not generated.

Herbivores such as cattle and sheep have a specialized digestive compartment called a ___ that provides an anaerobic environment for the microbial digestion of cellulose and hemicellulose and the fermentation of sugars that are released.

rumen

Sulfur-oxidizing bacteria (can sometimes grow in [rods OR filaments) + (can use hydrogen ___ or thiosulfate as an energy source). Extra credit: (They use ___ as a terminal electron acceptor) + (are Gram-negative ___)

(can sometimes grow in FILAMENTS) + (can use hydrogen SULFIDE or thiosulfate as an energy source). Extra credit: (They use O2 as a terminal electron acceptor) + (are Gram-negative RODS)

Hydrogen-oxidizing bacteria such as Aquifex and Hydrogenobacter are (obligate ____) + (Gram-___) + ____

(obligate CHEMOLITHOTROPHS) + (Gram-NEGATIVE) + thermophilic

Species of Pseudomonas (possess ___ flagella) + (use ___ as a terminal electron acceptor). Extra credit: (they do/do not ferment) + (are Gram ____ rods)

(possess POLAR flagella) + (use OXYGEN as a terminal electron acceptor). Extra credit: (they DO NOT ferment) + (are Gram-NEGATIVE rods)

What are some interesting facts about Mycobacterium?

- generally pleomorphic rods - occur in chains that sometimes branch or bunch together to form cord-like groups - more resistant to disinfectants that most other vegetative bacteria - are resistant to many of the most common antimicrobial medications - some notable species include: M. tuberculosis and M. leprae

What are some beneficial characteristics of nitrogen-fixing cyanobacteria?

1. providing an important source of USABLE NITROGEN and CARBON in NUTRIENT POOR ENVIRONMENTS 2. limiting atmospheric CO2 BUILDUP

To differentiate species in the family Enterobacteriaceae, a microbiologist could use which of the following methods? A. Biochemical tests B. Ability to ferment glucose C. Serological tests D. Gram stain

A and C

___ chemolithotrophs obtain energy by oxidizing reduced inorganic chemicals, using O2 as a terminal electron acceptor.***

Aerobic

Characterized members of the domain ___ typically thrive in extreme environments, such as high heat, acidity, alkalinity, and salinity.

Archaea

Most of the anaerobic chemolithotrophs that have been discovered are members of the domain ___.

Archaea

Why can Micrococcus easily contaminate bacteriological media?

Aside from inanimate objects and skin, these Gram-positive cocci are often found in soil, dust particles which are often airborne.

Which of the following is NOT a characteristic of the lactic acid bacteria? A. Produce lactic acid from fermentation B. Possess the enzyme catalse C. Most can grow in aerobic environments D. Can only ferment

B. Possess the enzyme catalase

The process of converting nitrogen gas (N2) to ammonia, which can then be incorporated into cell material, is called ___ ___.

nitrogen fixation

This member of the lactic acid group is a Gram-positive coccus that grows in the oral cavity and can cause pharyngitis (strep throat).

Streptococcus pyogenes

What are some commercially important characteristics of Thermus?

Thermus = thermophilic (heat-stable enzymes), unusual cell wall, stain Gram-negative

True or false: Methane gas produced by methanogens can be collected and used for generating electricity?

True

Biogeochemical cycles are important because _____.

a fixed and limited amount of elements that make up living cells exists on the earth and in the atmosphere

In lawns fertilized with acid-producing fertilizers such as ammonium chloride, mushrooms often appear. This is because _____.

acidity suppresses bacterial growth, allowing fungi to thrive with less competition for nutrients.

The cyanobacteria are the most significant nitrogen-fixers in ___ environments.

aquatic

Extreme thermophiles are found near ___ ___, ___ ___ and ___ ___

hydrothermal vents volcanic vents hot springs

Methanogens, a group of archaea that generate methane, can be found in environments that _____.

lack O2, contain H2, contain CO2.

A microbial ___ is a thick, dense, highly organized, multi-layered structure that contains multiple species of microbes.

mat

Because a single gram of soil may contain 10^4 and 10^7 different microbial species, less than 1% of which can be expected to grow under laboratory conditions, researchers often rely on ___ to attempt to quantify the rest of the microbial diversity present.

metagenomics

A ___ relationship is a symbiotic association in which both partners benefit

mutualistic

What can you say about Epilimnion and Hypolimnion

Epilimnion: upper layer, generally rich in oxygen Hypolimnion: may be anaerobic, lower layer

True or false? Nodule formation is based upon simple physical interactions between rhizobia and legume partners.

False - it's intensive!

Aerobic chemoorganotrophs obtain their energy by (using ___ as a terminal electron acceptor) + (producing CO2 and ___) + (oxidizing ___ compounds). Extra credit: name a compound it oxidizes

(using O2 as a terminal electron acceptor) + (producing CO2 and H2O) + (oxidizing organic compounds) Extra credit: glucose

Which of the following describe characteristcs of members of the genus Vibrio? Hint: Gram___ & shape. & in what environments could you find them?

Gram-negative straight or curved rods. Typically found in marine environments