A microbial consortium is two or more microbial groups living symbiotically. Consortiums can be endosymbiotic or ectosymbiotic. A microbial consortium is two or more microbial groups living symbiotically. Consortiums can be endosymbiotic or ectosymbiotic. The concept of consortium was first introduced by Johannes Reinke in 1872. The term preceded to the term symbiosis that was introduced into biology some years later.