Species is the most basic taxonomic unit, and each taxonomic unit can be followed by subfamily, subclass, suborder and subfamily ... Take beer yeast as an example, its taxonomic status is: Kindom: fungi.
Door: the door of fungi
Class: Ascomycetes
Objective: Endospore.
Family: Endospore.
Genus: Saccharomyces
Type: beer yeast
Species: it is the basic taxonomic unit; It is the general name of a large group of strains with highly similar phenotypic characteristics, extremely close genetic relationship and obvious differences from other species of the same genus. (1) strain refers to any purebred population propagated by an independent single cell and all its progeny (a group of purebred progeny flora that originated from the same ancestor of * * * and maintained its ancestral characteristics). Therefore, pure cultures of microorganisms from different sources can be called strains of this strain. This strain emphasizes genetic purity of pedigree. For example, two strains of Escherichia coli: Escherichia coli and Escherichia coli 12.
Expression of strains: if species is the basic unit of taxonomy, then strains are actually the basic unit of application, because different strains of the same strain will have great differences in enzyme production or metabolites! (2) Subspecies or varieties: intra-species reclassification.
When there are a few obvious and stable variation characteristics or genetic traits among different strains within a species, which are not enough to distinguish them as new species, these strains can be subdivided into two or more small taxonomic units-subspecies.
Variety is synonymous with subspecies, because the word "variety" is easy to cause confusion in meaning. After 1976, the word "variant" is no longer used. Mutant strains obtained in the laboratory are usually called subspecies.
For example, E.coli k 12 (wild type) does not need special aa, but after laboratory mutation, a deletion aa can be obtained from k 12, which is called a subspecies of E.coli k 12. (3) Form: often refers to the subdivision below subspecies. When the differences between different strains within the same species or subspecies are not enough to be divided into new subspecies, they can be subdivided into different types. For example, it can be divided into different serotypes according to the characteristics of antigens.
Naming of microorganisms: There are two kinds of naming of microorganisms: common names and scientific names. Such as: red bread mold-Neurospora crassa; Pseudomonas aeruginosa-Pseudomonas aeruginosa. Scientific name-is the scientific name of microorganism, which is named according to the rules drawn up by the International Committee for Microbial Classification. Scientific names consist of Latin words or Latin loanwords. There are two kinds of naming of scientific names: two-name method and three-name method. (1) binomial method: scientific name = generic name+species name+(first time)+current person name+naming year generic name: Latin noun or adjective used as noun, singular, capitalized, indicating the main characteristics of microorganisms, constructed and stereotyped by microorganisms or named by scientists. Name: Latin adjective with lowercase prefix, which is a secondary feature of microorganism, such as pigment, shape, origin of microorganism or name of scientist. E.coli castellanietchalmers1919.
Staphylococcus rosenbach 1884 refers to a certain genus of microorganisms, but not to a certain species (or unspecified species) in the genus. Or ssp. Can be added after the name of the genus (the singular and plural forms of abbreviations representing species respectively).
For example, yeast. Represents a species in the genus Saccharomyces. Strain name: add numbers, place names or symbols after the species name, for example, Bacillus subtilis 1.389as = academia sinica.
BacillussubtilisBF7658BF= north.
Clostridium acetobutylicum 824 Clostridium acetobutylicum
ATCC = American Type Culture Collection Center
When a scientific name has appeared in front of the article, its generic name can be abbreviated as 1~3 letters later.
For example, E.coli can be abbreviated as E.coli.
Staphylococcus aureus can be abbreviated as Staphylococcus aureus ②: used to name subspecies. At this time, a subspecies. It is added after the name of genus and species, and then the name of subspecies (oblique). For example: Bacillus thuringiensis subspecies. Bacillus thuringiensis subspecies. Cercospora sp.