From the Single Bacterial Cell to the Microbial Community: A Round Trip to better understand the Secrets of Complex Microbiological Ecosystems

There is increasing evidence of the difficulty in understanding the “biological functioning” of some complex microbial communities. Complex microbial communities exist everywhere in nature, and the interactions among their constituent microorganisms are a crucial aspect that influences their development. The ability of microorganisms to colonize an environment includes their ability to interact with other species in the same ecosystem, as well as their ability to adapt and integrate into the evolving community. The interactions among microorganisms and not just their numbers, or the presence of different species, biotypes, and variants, in many cases, seems to become a decisive factor in understanding and analyzing the development of microbial ecosystems and the biological function of the individual microbial entities that are part of them. After working to isolate individual microbial cells and study the mechanisms of their functioning and development, it is time to embark on a backward journey “from the small to the complex” for a better understanding of complex microbial ecosystems and their application potential. The purpose of this brief contribution is to further the development of the understanding of the role of microbial communities in nature and the mode of their development and evolution.