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Classification
The
taxonomy below is based on similarities of DNA sequences as well as
macroscopic characteristics. Many of the phylogenetic trees
are from the Taylor Lab's "Tree
of Life project" which has great information regarding numerous
organisms.
Domain:
Eukarya
There are three
groups within the broadest classification level of an organism.
Along with all other eukaryotes, P. chrysogenum is in
the group eukarya. This domain is characterized by organisms with
membrane bound organelles, complex cells, and genetic material
inside the nucleus.
Lineage:
Opisthokonta
There are eight
major lineages within the domain eukarya.
Though these lineages are not one of true (King Phillip
Came Over From Germany Sick)
taxonomic levels, it doesn’t hurt to add a little more
clarification. The opisthokonts include the mycrosporidians
(organisms closely related to fungi), the fungi, the
choanoflagellates (organisms closely related to animals), and the
animals. They are
characterized by having flagellated, motile cells at some point as
well as flattened mitochondrial cristae. This is the lineage which
shows that fungi are more closely related to animals than plants.
Who would have thought?
Kingdom:
Fungi
The kingdom
fungi are classified as eukaryotic, heterotrophic organisms with
cell walls made out of chitin.
Fungi can be either unicellular or multicellular and most
can reproduce both asexually and sexually.
Phylum:
Ascomycota or Not?
The groups
within the kingdom fungi are separated via their sexual reproductive
structures or lack there of. Interestingly,
P. chrysogenum does not show any mode of sexual reproduction.
Because of this, the fungus is put into a sort of “dumping
group” called the deuteromycetes.
However, as I’m sure you noticed by the enlarged font above,
I have classified it into the phylum ascomycota.
This was not a mistake.
Based on general morphology and DNA studies, it is safe to
assume P. chrysogenum into the phylum ascomycota.
Until the sexual state is discovered, however, it will also
belong to the dumping group (deuteromycetes).
Organisms within
ascomycota bear their sexual spores (ascospores) within a sac-like
structure called an ascus.
In fact, the ascomycota group is referred to as sac fungi.
Impress your friends by letting them know the Greek word “askos”
literally means “sac.”
Again, this refers to the sexual reproductive structure called an
ascus. P.
chrysogenum has yet to reveal this sexual structure.
However, like all other fungi within the ascomycota phylum,
its asexual spores are in the form of conidia.
Class: Euascomycetes
The Phylum ascomycota is generally broken down into two main groups, the
hemiascomycetes and the euascomycetes based on the presence or
absence of an ascocarp.
The ascocarp is the name of the fruiting body which contains the
sexual structures of the fungus.
In simpler terms, it’s a cluster of the sac-like sexual
structures which were previously described.
Many fungi within this class also form lichens, a symbiotic
relationship between a fungus and an algae or cyanobacteria.
Order:Eurotiales
The order eurotiales is also known as the plectomycetes.
Fungi within this group tend to have thin walled asci which
are scattered on the ascocarp.
The sexual structures tend to be spherical and closed (they
are described as being “cleistothecium”).
Organisms within this order usually release their spores
during decay or disintegration.
They are usually seen in the powdery mildew fungi.
Family: Trichocomaceae
The family trichocomaceae includes fungi which release their ascospores after the ascus is broken open.
The ascocarps (the fruiting body which contains multiple asci)
form clusters of threads which have a fuzzy texture.
The phylogenetic tree below is based on these morphological
characteristics as well as molecular characteristics, showing
similar DNA structures.
Genus: Penicillium
Fungi within the
genus Penicillium are filamentous and cotton-like in texture.
The colonies usually begin as a whitish color and, over time,
produce green, blueish green, grey, yellow, or pink hues.
Organisms within Penicillium tend to have flask-shaped
phialides (the structure which produces conidia). They are usually found in the air,
soil, or decaying materials and are associated with infections as
well as mycotoxins. Contrary to this, some fungi in this genus (such as Penicillium
chrysogenum) have beneficial characteristics. If
you would like to see pictures of the characteristic paintbrush
conidia, click here.
There are many
genera within the Trichocomaceae family, the phylogenetic tree
below shows a few of the many relatives of the Penicillium
genus on a molecular level, based on similar DNA sequences.
Species:
P. chrysogenum
The species
Penicillium chrysogenum is classified by its unique macroscopic
morphology as well as microscopic features. P. chrysogenum is
able to break down gram-positive (and not gram-negative) bacteria.
Because of this, it is known to produce the common drug
penicillin which was a great help during World War II (more about
this in Penicillin – The wonder drug).
Similar to the genus phylogenic tree, the number of species within
Penicillium is way too high to list them all.
I have included some of the most common species below.
They, too, are placed in the specific species based on unique
macroscopic and microscopic characteristics.
Relatives
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