Shared Flashcard Set

Details

Microbial Terms
REHS
15
Environmental Studies
Professional
08/30/2013

Additional Environmental Studies Flashcards

 


 

Cards

Term
Obligate Aerobes
Definition
An aerobic prokaryote that cannot survive without oxygen (O2).
Term
Obligate Anaerobes
Definition
An anaerobic prokaryote that cannot survive exposure to oxygen (O2).
Term
Facultative Anaerobes
Definition
A prokaryote that can shift its metabolism between anaerobic and aerobic operations modes on the presence or absence of O2.
Term
Psychrophiles
ch. 6 Bio 220
Definition
Organisms such as fungi and bacteria that show optimum growth at extremely low temperatures. (optimum temp)
Term
Mesophiles
ch. 6 Bio 220
Definition
-majority of medically significant microorganisms
-grow at intermediate temperatures between 20°C and 40°C
-inhabit animals and plants as well as soil and water in temperate, subtropical, and tropical regions
-human pathogens have optimal temperatures between 30°C and 40°C
Term
Thermophiles
ch. 6 Bio 220
Definition
-grows optimally at temperatures greater than 45°C
-live in soil and water associated with volcanic activity, compost piles, and in habitats directly exposed to the sun
-vary in heat requirements with a range of growth of 45°C to 80°C
-most eukaryotic forms cannot survive above 60°C
•Extreme thermophiles grow between 80°C and 121°C
Term
Acidophiles
ch. 6 Bio 220
Definition
Organisms that thrive in acidic environments

-Euglena mutabilis: grows in acid pools between pH 0 and 1
-Thermoplasma: lives in coal piles at a pH of 1 or 2
-Picrophilus: thrives at a pH of 7, but can live at a pH of 0
-Many molds and yeasts tolerate acid and are the primary spoilage agents of pickled foods
Term
Halophiles
ch. 6 Bio 220
Definition
Prefer high concentration of salt

-Obligate halophiles Halobacterium and Halococcus grow optimally at solutions of 25% NaCl but require at least 9% NaCl
-Facultative halophiles: remarkably resistant to salt, even though they do not normally reside in high salt environments
-Staphylococcus aureus can grow on NaCl media ranging from 0.1% to 20%
Term
Alkalophiles
ch. 6 Bio 220
Definition
Organisms that thrive in alkaline conditions

-Natromonas: live in hot pools and soils at pH 12
-Proteus: can create alkaline conditions to neutralize urine and colonize and infect the urinary system
Term
Neutrophiles
ch. 6 Bio 220
Definition
The majority of organisms live or grow in habitats between pH 6 and 8 because strong acids and bases can be damaging to enzymes and other cellular substances
Term
Halotolerant
Definition
The adaptation of living organisms to conditions of high salinity. Halotolerant species tend to live in areas such as hypersaline lakes, coastal dunes, saline deserts, salt marshes, and inland salt seas and springs. Halophiles live in highly saline environments, and require the salinity to survive, while halotolerant organisms (belonging to different domains of life) can grow under saline conditions, but do not require elevated concentrations of salt for growth.
Term
Osmophiles
ch. 6 Bio 220
Definition
live in habitats with high solute concentration
Term
Xerophiles
Definition
Plant/organism adapted for life with a limited supply of water/..
Term
Endotoxin
Definition
A toxin that is confined inside the microorganisms and is released only when the microorganisms are broken down or die.

A lipopolysaccharide that forms part of the outer membrane of certain gram negative bacteria that is released when the bacteria grow or lyse (destruction).
Term
Exotoxin
Definition
A toxin that is secreted by microorganisms into the surrounding medium.

A highly toxic, usually soluble protein released by living, multiplying bacteria.
Supporting users have an ad free experience!