Bacteria, those microscopic creatures that usually live in communities, have astonished scientists with their incredible teamwork and their ability to share nutrients. Scientists at the University of Basel have unraveled the mysterious ways in which bacteria support one another across generations. Breaking new ground with their innovative technique, researchers have successfully tracked the gene expression during the development of bacterial communities over time and space.
These findings shed light on the complex nature of bacterial communities, offering a glimpse into their intricate world. These remarkable findings bring us closer to unraveling the secrets of the microbial world, reminding us that even the tiniest organisms can teach us profound lessons about the power of cooperation and support.
Leading the study, Professor Knut Drescher from the Biozentrum at the University of Basel explains, "We used Bacillus subtilis as a model organism. This ubiquitous bacterium, found in our gut microbiome, has shown us that these tiny beings not only live in communities but also cooperate and interact with each other across generations."
The research team's pioneering technique allowed them to simultaneously measure gene expression while observing the behavior of individual cells in microbial communities. This breakthrough revealed that earlier generations of bacteria deposit metabolites that serve as resources for future generations.
Moreover, the team discovered different subpopulations within the bacterial swarm, each producing and consuming different metabolites. Some of these secreted metabolites serve as nourishment for subsequent subpopulations that emerge during swarm development.
To achieve these extraordinary results, the scientists combined state-of-the-art adaptive microscopy, gene expression analyses, metabolite analyses, and robotic sampling. This innovative approach enabled them to capture gene expression and bacterial behavior at specific times and locations, as well as identify the metabolites secreted by the bacteria.
The bacterial swarm, as observed in the study, can be divided into three major regions: the swarm front, the intermediate region, and the swarm center. However, the transitions between these regions are gradual.
As first author Hannah Jeckel explains, "Depending on the region, the bacteria differ in appearance, characteristics, and behavior. While they are mostly motile at the edges, the bacteria in the center form long non-motile threads, resulting in a 3D biofilm. One reason for this variation is the availability of space and resources."
This astonishing spatial distribution of bacteria with distinct behaviours allows the community to expand and, at the same time, seek refuge in a protective biofilm—a strategy crucial for the survival of bacterial communities.
