The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology In general the field of microbiology can be divided in the more fundamental branch and the applied microbiology. In the more fundamental field the organisms are studied as the subject itself on a deeper level. Applied microbiology refers to the fields where the micro-organisms are applied in certain processes such as brewing or fermentation. The organisms itself are often not studied as such, but applied to sustain certain processes.
Microbial ecology: the relationship between microorganisms and their environment
Microbial genetics: the study of how genes are organized and regulated in microbes in relation to their cellular functions Closely related to the field of molecular biology
Cellular microbiology: a discipline bridging microbiology and cell biology
Evolutionary microbiology: the study of the evolution of microbes. This field can be subdivided into:
* Microbial taxonomy: the naming and classification of microorganisms
* Microbial systematics: the study of the diversity and genetic relationship of microorganisms
Generation microbiology: the study of those microorganisms that have the same characters as their parents
Systems microbiology: a discipline bridging systems biology and microbiology.
Molecular microbiology: the study of the molecular principles of the physiological processes in microorganisms
Phylogeny: the study of the genetic relationships between different organisms
Biological agent: the study of those microorganisms which are being used in weapon industries.
Nano microbiology: the study of those organisms on nano level.
Predictive microbiology: the quantification of relations between controlling factors in foods and responses of pathogenic and spoilage microorganisms using mathematical modelling
Pharmaceutical microbiology: the study of microorganisms that are related to the production of antibiotics, enzymes, vitamins, vaccines, and other pharmaceutical products and that cause pharmaceutical contamination and spoil.
Microbial biotechnology: the manipulation of microorganisms at the genetic and molecular level to generate useful products.
Food microbiology: the study of microorganisms causing food spoilage and foodborne illness. Using microorganisms to produce foods, for example by fermentation.
Agricultural microbiology: the study of agriculturally relevant microorganisms. This field can be further classified into the following:
* Soil microbiology: the study of those microorganisms that are found in soil.
Veterinary microbiology: the study of the role of microbes in veterinary medicine or animal taxonomy.
Environmental microbiology: the study of the function and diversity of microbes in their natural environments. This involves the characterization of key bacterial habitats such as the rhizosphere and phyllosphere, soil and groundwater ecosystems, open oceans or extreme environments. This field includes other branches of microbiology such as: