What is a microbial species or the concept of microbial species?
A microbial species may be regarded as a group of individual populations or strains that show a high level of similarity and differ from populations or strains in related groups. In case of bacterial species the members of the same species possess DNA homology values above 70 percent. Also the bacterial species have a limited range of mole per cent G + C as the DNA molecules with significant differences in mole per cent G + C do not show a high level of homology. The species is a taxonomic category ranking just below a genus. The individuals of a species exhibit a high degree of mutual similarity.
In the higher organisms which reproduce by sexual reproduction, the members of a species can inbreed actually or potentially.