Glossary
Acetic acid bacteria Acetic
acid bacteria belong to the family Acetobacteriaceae,
commonly
known as vinegar bacteria, and are often responsible for the vinegary
spoilage of wines through the production of acetaldehyde and acetic
acid from ethanol (and glucose).
Agar
1. A gelatinous material, an extract from red algae (mainly Gelidium
and Gracilaria species),
used as a base for bacterial culture media and
as a stabilizer and thickener in many food products.
2. A culture medium containing this material
Apiculate Terminating in a
short, sharp, flexible point.
Asexual Not forming part of a
cycle which involves fertilisation and meiosis
Asexual reproduction
Reproduction in which an organism produces one or more clones of
itself, such as by fission or budding.
Bacteria
Tiny, unicellular,
prokaryotic organisms that reproduce by cell division and usually have
cell walls; can be shaped like spheres, rods or spirals and can be
found in virtually any environment.
Budding
Asexual reproduction
(usually in yeasts) beginning as a protuberance from the parent cell
that grows to become a daughter cell
Coccoid Sphere-shaped.
Coccus,
pl cocci A bacterium
with a rounded or spherical shape.
Diplococcus A pair of cocci.
Diploid
A full set of genetic
material, consisting of paired chromosomes
Eukaryote
A single-celled or
multicellular organism whose cells contain a distinct membrane-bound
nucleus.
Fermentative Capable of
performing fermentation
Fermentation
The chemical
decomposition of a substance, usually a carbohydrate, due to the action
of enzymes produced by bacteria, yeasts or moulds. Fermentation
usually occurs in an oxygen-free environment, and typically involves
the conversion of starch or sugar into ethanol.
Fission budding A type of cell
division in which overall (i.e. not localised) cell growth is followed
by septum formation which typically divides the fully grown cell into
two similar or identical cells.
Fungus
Any of
numerous eukaryotic organisms of the kingdom Fungi, which lack chlorophyll and vascular tissue and range in form from a single cell to a body mass of branched filamentous hyphae that often produce specialized fruiting bodies. The kingdom includes the yeasts, moulds, smuts, and mushrooms.
Genus -
plural Genera The
second most specific taxonomic level; includes closely related species.
Interbreeding between organisms within the same genus can occur.
Haploid
A single set of
chromosomes (half the full set of genetic material), present in the egg
and sperm cells of animals and in the egg and pollen cells of plants.
Hyphae Any of the threadlike
filaments forming the mycelium of a fungus.
Inoculating loop A small loop
of wire on a handle that is used to transfer microbiological samples,
aseptically.
Inoculum
Material used to initiate a microbial culture.
Killer yeast A yeast that
secretes a toxin that can kill other yeasts
Lactic acid
bacteria Those
bacteria which can produce lactic acid from the fermentation of glucose.
Lenticular Shaped like a
biconvex lens: ().
Malo-lactic
fermentation (MLF)
The conversion of malic acid to lactic acid and carbon dioxide, carried
out by some of the lactic acid bacteria.
Meiosis
The process of cell
division in sexually reproducing organisms that reduces the number of
chromosomes in reproductive cells from diploid to haploid, leading to
the production of gametes in animals and spores in plants.
Mould
A filamentous fungus
Mycelium The diffuse,
indefinite body of a multicellular fungus,
which is composed of many
fine, branching tubes called hyphae.
Oenococcus oeni
Formerly known as Leuconostoc oenos,
the bacteria most often responsible for malolactic
fermentation in
winemaking.
Ogival A pointed arch
Phylum
A primary division of a
kingdom, as of the animal kingdom, ranking next above a class in size.
Prokaryote a unicellular
organism having cells lacking membrane-bound nuclei; bacteria are the
prime example but also included are blue-green algae and actinomycetes
and mycoplasma
Saccharomyces
cerevisiae The
yeast most commonly responsible for
alcoholic fermentation in
winemaking.
Sexual reproduction The process
where two cells (gametes) fuse to form one hybrid, fertilised cell;
resulting in a new genome that is different from that of either parent.
Spore A small, usually
single-celled reproductive body that is highly resistant to desiccation
and heat and is capable of growing into a new organism, produced
especially by certain bacteria, fungi, algae, and non-flowering plants.
Sporulating Spore-forming
Strain A group of organisms of
the same species, having distinctive characteristics but not usually
considered a separate breed or variety:
Taxonomy The classification of
organisms in an ordered system that indicates natural
relationships. The taxonomic organisation of species is
hierarchical. Each species belongs to a genus,
each genus belongs to a
family, and so on through order, class, phylum,
and kingdom.
Associations within the hierarchy reflect evolutionary relationships,
which are deduced typically from morphological and physiological
similarities between species. So, for example, species in the same
genus are more closely related and more alike than species that are in
different genera within the same family. Carolus Linnaeus, an
18th-century Swedish botanist, devised the system of binomial
nomenclature used for naming species. In this system, each species is
given a two-part Latin name, formed by appending a specific epithet to
the genus name. By convention, the genus name is capitalised, and both
the genus name and specific epithet are italicised, for example
Oenococcus oeni
Tetrad A group of four
Yeast
Any of many small,
single-celled fungi in the phylum Ascomycota that reproduce by budding;
the yeasts used to produce alcohol through fermentation or to leaven
bread are all in the genus Saccharomyces.