acidophile
organism with optimal growth pH of three or below
alkaliphile
organism with optimal growth pH of nine or above
ammonification
process by which ammonia is released during the decomposition of nitrogen-containing organic compounds
anaerobic
refers to organisms that grow without oxygen
anoxic
without oxygen
antibiotic
biological substance that, in low concentration, is antagonistic to the growth of prokaryotes
biofilm
microbial community that is held together by a gummy-textured matrix
biological nitrogen fixation
conversion of atmospheric nitrogen into ammonia exclusively carried out by prokaryotes
bioremediation
use of microbial metabolism to remove pollutants
biotechnology
any technological application that uses living organisms, biological systems, or their derivatives to produce or modify other products
Black Death
devastating pandemic that is believed to have been an outbreak of bubonic plague caused by the bacterium Yersinia pestis
botulism
disease produce by the toxin of the anaerobic bacterium Clostridium botulinum
CA-MRSA
MRSA acquired in the community rather than in a hospital setting
capsule
external structure that enables a prokaryote to attach to surfaces and protects it from dehydration
chemotroph
organism that obtains energy from chemical compounds
conjugation
process by which prokaryotes move DNA from one individual to another using a pilus
cyanobacteria
bacteria that evolved from early phototrophs and oxygenated the atmosphere; also known as blue-green algae
decomposer
organism that carries out the decomposition of dead organisms
denitrification
transformation of nitrate from soil to gaseous nitrogen compounds such as N2O, NO and N2
emerging disease
disease making an initial appearance in a population or that is increasing in incidence or geographic range
endemic disease
disease that is constantly present, usually at low incidence, in a population
epidemic
disease that occurs in an unusually high number of individuals in a population at the same time
extremophile
organism that grows under extreme or harsh conditions
foodborne disease
any illness resulting from the consumption of contaminated food, or of the pathogenic bacteria, viruses, or other parasites that contaminate food
Gram negative
bacterium whose cell wall contains little peptidoglycan but has an outer membrane
Gram positive
bacterium that contains mainly peptidoglycan in its cell walls
halophile
organism that require a salt concentration of at least 0.2 M
hydrothermal vent
fissure in Earth’s surface that releases geothermally heated water
hyperthermophile
organism that grows at temperatures between 80–122 °C
microbial mat
multi-layered sheet of prokaryotes that may include bacteria and archaea
MRSA
(methicillin-resistant Staphylococcus aureus) very dangerous Staphylococcus aureus strain resistant to multiple antibiotics
nitrification
conversion of ammonium into nitrite and nitrate in soils
nitrogen fixation
process by which gaseous nitrogen is transformed, or “fixed” into more readily available forms such as ammonia
nodule
novel structure on the roots of certain plants (legumes) that results from the symbiotic interaction between the plant and soil bacteria, is the site of nitrogen fixation
nutrient
essential substances for growth, such as carbon and nitrogen
osmophile
organism that grows in a high sugar concentration
pandemic
widespread, usually worldwide, epidemic disease
peptidoglycan
material composed of polysaccharide chains cross-linked to unusual peptides
phototroph
organism that is able to make its own food by converting solar energy to chemical energy
pilus
surface appendage of some prokaryotes used for attachment to surfaces including other prokaryotes
pseudopeptidoglycan
component of archaea cell walls that is similar to peptidoglycan in morphology but contains different sugars
psychrophile
organism that grows at temperatures of –15 °C or lower
radioresistant
organism that grows in high levels of radiation
resuscitation
process by which prokaryotes that are in the VBNC state return to viability
S-layer
surface-layer protein present on the outside of cell walls of archaea and bacteria
serotype
strain of bacteria that carries a set of similar antigens on its cell surface, often many in a bacterial species
stromatolite
layered sedimentary structure formed by precipitation of minerals by prokaryotes in microbial mats
teichoic acid
polymer associated with the cell wall of Gram-positive bacteria
thermophile
organism that lives at temperatures between 60–80 °C
transduction
process by which a bacteriophage moves DNA from one prokaryote to another
transformation
process by which a prokaryote takes in DNA found in its environment that is shed by other prokaryotes
viable-but-non-culturable (VBNC) state
survival mechanism of bacteria facing environmental stress conditions
zoonosis
disease that primarily infects animals that is transmitted to humans