Microbiology terms - A


B cell
See B lymphocyte.
bacillus (plural: bacilli)
A bacterium with a elongated, rod shape.
Bacillus
A bacterial genus in which members are rod-shaped, gram-positive, endospore-forming, and, depending on species, aerobic or facultatively anaerobic. Type species: B. subtilis.
bacteremia
The transient appearance of bacteria in the blood.
bacterium (plural bacteria)
See prokaryote.
Bacteria
All prokaryotes that are not members of the domain Archaea.
bactericidal
Capable of killing bacteria.
bacteriochlorophyll
The light-absorbing pigment found in green sulfur and purple sulfur bacteria.
bacteriocin
Agents produced by certain bacteria that inhibit or kill closedly related species.
bacteriophage
A virus that infects a bacterium or prokaryotes.
bacteriorhodopsin
A protein containing retinal found in the membranes of certain extremely halophilic Archaea and which is involved in light-mediated ATP synthesis.
bacteriostatic
Capable of inhibiting bacterial growth without killing.
bacteroid
A swollen, deformed Rhizobium cell, found in the root nodule; capable of symbiotic nitrogen fixation.
barophile
An organism able to live optimally at high hydrostatic pressure.
barotolerant
An organism able to tolerate high hydrostatic pressure, although growing better at normal pressures.
basal medium
A(n) (unsupplemented) medium which allows the growth of many types of microorganisms which do not require any special nutrient supplements, e.g. nutrient broth.
base composition
In reference to nucleic acid, the proportion of the total bases consisting of guanine plus cytosine or thymine plus adenine base pairs. Usually expressed as a guanine + cytosine (G+C) value, e.g. 60% G+C.
bdelloplast
See Bdellovibrio
binary fission
The division of one cell into two (typically similar or identical ) cells by the formation of a septum is call binary fission. It is the commonest form of cell division in bacteria. If the daughter cells are not similar (in size) to the parent cell, it is called asymmetrical binary fission. Asymmetrical binary fission occurs e.g. in Caulobacter.
binomial nomenclature
The system of having two names (genus and specific epithet, also called Latin binomial) for each organism.
bioconversion
In industrial microbiology, use of microorganisms to convert an added chemical to a chemically modified form.
biofilm
Microbial colonies encased in an adhesive, usually polysaccharide material, and attached to a surface.
biogeochemistry
Study of microbially mediated chemical transformations of geochemical interest, e.g. nitrogen or sulfur cycling.
bioremediation
Use of microorganisms to remove or detoxify toxic or unwanted chemicals from an environment.
biosynthesis
The production of needed cellular constituents from other (usually simpler) molecules.
biotechnology
The use of living organisms to carry out defined chemical processes for industrial application.
black smoker
Thermal vent emitting very hot (270-380 °C) water and minerals.
blastomycosis
An acute or chronic mycosis which usually affects man and animals (e.g. dogs). Blastomycosis is caused by a fungus called Blastomyces dermatitidis and occurs in North America, Africa and Israel. Infection apparently occurs by inhalation of spores from the fungus although B. dermatitidis has proved difficult to isolate from environmental habitats.
B lymphocyte
A cell of the immune system that differentiates into an immunoglobulin-producing cell.
biochemical oxygen demand (BOD)
The oxygen-consuming property of a body of water determined by taking a sample of water, aerating it well, placing it in a sealed bottle, incubating for a standard period of time (usually 5 days at 20 °C), and determining the residual oxygen in the water at the end of incubation.
brewing
The manufacture of alcoholic beverages such as beer from the fermentation of malted grains.
budding
1. Asexual reproduction (usually 4yeasts) beginning as a protuberance from the parent cell that grows to become a daughter cell

2. Release of an enveloped virus through the plasma membrane of an animal cell.


Compiled by Tsute Chen, Converted by Ben Hoyt