Microbiology
The branches of microbiology can be classified into pure and applied sciences, or divided according to taxonomy, as is the case with 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
While some fear microbes due to the association of some microbes with various human diseases, many microbes are also responsible for numerous beneficial processes such as industrial fermentation (e.g. the production of alcohol, vinegar and dairy products), antibiotic production and act as molecular vehicles to transfer DNA to complex organisms such as plants and animals. Scientists have also exploited their knowledge of microbes to produce biotechnologically important enzymes such as Taq polymerase, reporter genes for use in other genetic systems and novel molecular biology techniques such as the yeast two-hybrid system.
Microbial population biology
Microbial population biology can (and often does) involve the testing of more-general ecological and evolutionary hypotheses. Again, it is important to retain some emphasis on the microbe since at some point this "question-driven" microbial population biology becomes instead population biology using microorganisms. Because the point of departure of these potentially disparate emphases can be somewhat arbitrary, there exist vague and not universally accepted delimits around what the discipline of microbial population biology does and does not constitute.