Acidophile
organism with optimal growth pH of three or below
Alkaliphile
organism with optimal growth 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 produced by the toxin of the anaerobic bacterium Clostridium botulinum
CA-MRSA
MRSA acquired in the community rather than in a hospital
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, 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 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 Earthâs surface that releases geothermally heated water
Hyperthermophile
organism that grows at temperatures between 80â122 °C
Microbial mat
multi-layered sheet of prokaryotes that may include bacteria and archaea
MRSA
very dangerous Staphylococcus aureus strain resistant to multiple antibiotics
Nitrification
conversion of ammonium into nitrate and nitrate into soils
Nitrogen fixation
process by which gaseous nitrogen is transformed, or âfixedâ 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, and is the site of nitrogen fixation
Nutrient
essential substances for growth, such as carbon and nitrogen
Osmophile
organism that grows in a higher 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 bacterium that carries a set of similar antigens on its cell surface, often many in 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 60â80 °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
Biological carbon pump
process by which inorganic carbon is fixed by photosynthetic species that then die and fall to the sea floor where they cannot be reached by saprobes and their carbon dioxide consumption cannot be returned to the atmosphere
Bioluminescence
generation and emission of light by an organism, as in dinoflagellates
Contractile vacuole
vesicle that fills with water (as it enters the cell by osmosis) and then contracts to squeeze water from the cell; an osmoregulatory vesicle
Cytoplasmic streaming
movement of cytoplasm into an extended pseudopod such that the entire cell is transported to the site of the pseudopod
Endosymbiosis
engulfment of one cell within another such that the engulfed cell survives, and both cells benefit; the process responsible for the evolution of the mitochondria and chloroplasts in eukaryotes
Endosymbiotic theory
theory that states that eukaryotes may have been a product of one cell engulfing another, one living within another, and evolving over time until the separate cells were no longer recognizable as such
Hydrogenosome
organelle carried by parabasalids (Excavata) that functions anaerobically and outputs hydrogen gas as a byproduct; likely evolved from mitochondria
Kinetoplast
mass of DNA carried within the single, oversized mitochondrion, characteristic of kinetoplastids (phylum: Euglenozoa)
Mitosome
nonfunctional organelle carried in the cells of diplomonads (excavata) that likely evolved from a mitochondrion
Mixotroph
organism that can obtain nutrition by autotrophic or heterotrophic means, usually facultatively
Pellicle
outer cell covering composed of interlocking protein strips that function like a flexible coat of armor, preventing cells from being torn or pierced without compromising their ranger of motion
Phagolysosome
cellular body formed by the union of a phagosome containing the ingested particle with a lysosome that contains hydrolytic enzymes
Plankton
diverse group of mostly microscopic organisms that drift in marine and freshwater systems and serve as a food source for larger aquatic organisms
Plastid
one of a group related organelles in plant cells that are involved in the storage of starches, fats, proteins, and pigments
Raphe
slit in the silica shell of diatoms through which the protist secretes a stream of mucopolysaccharides for locomotion and attachment to substrates
Test
porous shell of a foram that is built from various organic materials and typically hardened with calcium carbonate
Arbuscular mycorrhiza
mycorrhizal association in which the fungal hyphae enter the root cells and form extensive networks
Arbuscular mycorrhizae
mycorrhizae commonly involving Glomeromycetes in which fungal hyphae penetrate the cell walls of the plant root cells (but not the cell membranes)
Ascocarp
fruiting body of ascomycetes
Ascomycota
(also, sac fungi) phylum of fungi that store spores in a sac called ascus
Basidiocarp
fruiting body that protrudes from the group and bears the basidia
Basidiomycota
(also, club fungi) phylum of fungi that produce club-shaped structures (basidia) that contain spores
Basidium
club-shaped fruiting body of basidiomycetes
Chytridiomycota
(also, Chytrids) primitive phylum of fungi that in water and produce gametes with flagella
Coenocytic hypha
single hypha that lacks septa and contains many nuclei
Commensalism
symbiotic relationship in which one member benefits while the other member is not affected
Deuteromtcota
former form phylum of fungi that do not have a known sexual reproductive cycle (presently members of two phyla: Ascomycota and Basidiomycota)
Ectomycorrhiza
mycorrhizal fungi that surround the roots with a mantle and have a Hartig net that extends into the roots between cells
Ectomycorrhizae
mycorrhizae in which the fungal hyphae do not penetrate the root cells of the plant
Facultative anaerobes
organisms that can perform aerobic and anaerobic respiration and can survive in oxygen-rich and oxygen-poor environment
Glomeromycota
phylum of fungi that form symbiotic relationships with the roots of trees
Haustoria
modified hyphae on many parasitic fungi that penetrate the tissues of their hosts, release digestive enzymes, and/or absorb nutrients from the host
Heterothallic
describes when only one mating type is present in an individual mycelium
Homothallic
describes when both mating types are present in mycelium
Hypha
fungal filament composed of one or more cells
Karyogamy
fusion of nuclei
Lichen
close association of a fungus with a photosynthetic alga or bacterium that benefits both partners
Mold
tangle of visible mycelia with a fuzzy appearance
Mycelium
mass of fungal hyphae
Mycetismus
ingestion of toxins in poisonous mushrooms
Mycology
scientific study of fungi
Mycorrhizae
a mutualistic relationship between a plant and a fungus. Mycorrhizae are connections between fungal hyphae, which provide soil minerals to the plant, and plant roots, which provide carbohydrates to the fungus
Mycosis
fungal infection
mycotoxicosis
poisoning by a fungal toxin released in food
Obligate aerobes
organisms, such as humans, that must perform aerobic respiration to survive
Obligate anaerobes
organisms that only perform anaerobic respiration and often cannot survive in the presence of oxygen
Parasitism
symbiotic relationship in which one member of the association benefits at the expense of the other