Microbial Diversity: The Gap between the Estimated and the Known

The ecological and biotechnological services that microorganisms provide to the planet and human society highlight the need to understand and preserve microbial diversity, which is widely distributed, challenging the severity of certain environments. Cataloging this diversity has also challenged the methods that are currently used to isolate and grow microorganisms, because most of the microbiota that are present in environmental samples have been described as unculturable. Factors such as geographic isolation and host preference also hinder the assessment of microbial diversity. However, prejudiced historical practices, including the prioritization of some species of microorganisms merely because they cause diseases, have long shifted research on fungi and bacteria towards medically relevant microorganisms. Thus, most microorganisms that inhabit the planet are still unknown, as is the potential of these species. Current estimates allow us to predict that the diversity of microorganisms that are present in the various terrestrial ecosystems is enormous. However, understanding this diversity is a challenge for the future of microbial ecology research.