The research, led by Dr. Mireia Mestre and Dr. Juan Höfer, proposes a new theory and was published in the prestigious scientific journal Trends in Microbiology.
“We propose that everything is connected and that the dispersal of microorganisms is not entirely random, but occurs continuously in time and cyclically in space”, says Dr. Juan Höfer.
Andrea Navarro, IDEAL Center. They exist in abundance in the oceans, continents and the atmosphere, they play a key role on the planet, and yet we can only see them through a microscope. Microorganisms are capable of forming complex communities with multiple species of bacteria, microalgae and fungi, among others.
Despite the fact that humans generally perceive them as pathogens, their functions within ecosystems are multiple, essential and without them, life on Earth would not exist. For example, they are responsible for absorbing carbon and nutrients and converting them into food for other species.
Since the early 1900s, the scientific community has debated whether or not all microorganisms are found in all parts of the planet. Despite the recent increase in knowledge in microbiology, the processes that determine the distribution and functioning of microorganisms have not been unraveled. Until now.
New research published in the prestigious journal Trends in Microbiology of the Editorial Cell Press, proposes that there is a global, recurrent and spatially cyclical dispersion of the microbial community, capable of connecting very distant ecosystems. Dr. Mireia Mestre and Dr. Juan Höfer, authors of the study and researchers from the Center for Dynamic Research on Marine Ecosystems of High Latitude (IDEAL) of the Austral University of Chile (UACh), have called this process “the microbial conveyor belt.”
The study shows how the inactive stages (latent or dormant) of microorganisms are adapted to withstand specific adverse conditions, suggesting that dispersal is not a completely random process. Added to this, long-lasting dormant periods facilitate dispersal. Both evidences and an extensive bibliographic review, led scientists to postulate the new concept.
“We propose that everything is connected and that the dispersal of microorganisms is not entirely random, but occurs continuously in time and cyclically in space. For example, in the oceans there are microalgae that turn into spores and end up on the seabed. They stop their biological activity for many years, even centuries, until the wind and currents bring them back to the surface,” explains Dr. Höfer, researcher at the IDEAL Center and academic at the Pontificia Universidad Católica de Valparaíso (PUCV).
“Dispersion cycles have a direct influence on the distribution of microorganisms and, therefore, on the functioning of the terrestrial system. The existence of the ‘microbial conveyor belt’ can only be understood if we take into account the evolution of life on planet Earth,” says Dr. Mestre, lead author of the study and researcher at the IDEAL Center and COPAS-Sur Austral of the University of Concepción (UdeC).
COVID-19
“Dispersion cycles have a direct influence on the distribution of microorganisms and, therefore, on the functioning of the terrestrial system”, says Dr. Mireia Mestre.
In the current context of a pandemic, the new research takes on special relevance. Scientists suggest that disrupting the “microbial conveyor belt” can have unintended and damaging consequences such as altering microbial diversity and thus ecosystem services that support human well-being.
Degraded ecosystems and altered dispersal vectors favor the appearance and spread of opportunistic and pathogenic microorganisms. In this context, the constant alteration of the “microbial conveyor belt” increases the risk of zoonoses, diseases originated in other animals that are transmitted to the human species.
Although the most well-known zoonoses are related to viruses such as COVID-19 or Ebola, other microorganisms such as bacteria also cause zoonoses that compromise public health and food safety and also commonly go unnoticed by the public opinion despite its severity.
“The dispersion cycles have occurred for millennia. If they are disturbed, they facilitate the appearance of these diseases: microorganisms that were dormant for a long time can appear and in a context of global change, this could significantly harm our well-being through consequences that are impossible to predict,” warns Dr. Höfer.
“Recently, the Intergovernmental Panel for Biodiversity and Ecosystem Services (IPBES) launched a report where the loss of the planet’s biodiversity is directly linked to the appearance of pandemics; they conclude that the best way to avoid them is by conserving the environment. With our work we can contribute that, in addition to this, we must also conserve the natural flow of microorganisms that connects the different ecosystems. It is essential to describe and understand the ‘microbial conveyor belt’ to preserve global dispersal mechanisms and, therefore, help prevent the appearance of new pandemics,” concludes Dr. Mestre.