How do microbes move through the world?
How do microbes move through the world?
By Antonella Colque
**Microbes are constantly on the move. Despite their size, their journeys are anything but simple. Microbes navigate their environments using specialized structures and strategies to find food, escape danger, and colonize new territories. **
Why do microbes move?
Microbes move for many of the same reasons animals do: to survive. Locomotion helps them locate nutrients, avoid harmful substances, and interact with other organisms. This behavior, known as motility, is essential for their success in diverse environments, from oceans and soil to the human body.
do they move alone or togetheR?
Some microbes move individually, while others coordinate in large groups, forming swarms or biofilms. These mass movements can be surprisingly organized, sometimes resembling traffic patterns in cities. According to research published in Science, microbial communities often respond collectively to environmental cues, such as nutrient gradients or stressors, by altering their gene expression and physical organization. This coordinated behavior enables microbes to adapt rapidly and efficiently to changing conditions. Notably, microbial mobility also plays a role in the spread of antibiotic resistance genes, especially through mobile genetic elements like integrons, which can be transferred across populations during these coordinated movements.
how do microbes move?
One of the most iconic tools microbes use to move is the flagellum, a thin, helical appendage that acts like a tiny motor. In bacteria such as Escherichia coli, the flagellum rotates like a propeller, propelling the cell forward through its environment. This rotation is powered by a complex molecular machine embedded in the cell membrane, which converts chemical energy into mechanical motion (Nature Reviews Microbiology).
But not all microbes use flagella. Several members of the phylum Bacteriodetes glide along surfaces by driving specific proteins called adhesins. Others use twitching motility, powered by pili (short, hair-like structures) that extend and retract to pull the cell forward. Some bacteria exhibit swarming motility, where thousands of cells move together across surfaces in a coordinated fashion. This behavior is prevalent among several bacterial species, including Salmonella, Pseudomonas, and Serratia.
Protists, a group of single-celled eukaryotic organisms, use different stratefies. Many swim using cilia, tiny hair-like structures that beat rhythmically, while others crawl using pseudopodia, temporary extensions of their cell body. Want to see this in action?
Check out this cool video of Microbes in slow motion, which beautifully illustrates the elegance of microbial movement.
how do microbes know where to go?
Microbes don’t just move randomly, they often follow chemical signals in a process called chemotaxis. For example, when a bacterium senses a nutrient source, it will swim toward it. If it detects a harmful substance, it will change direction to escape. This decision-making process is surprisingly complex for such tiny organisms and involves intricate signaling pathways inside the cell (University of Wisconsin Microbiology Textbook).
MICROBES AND MOVEMENT
Microbial locomotion is a remarkable example of how life adapts to its environment, even at the smallest scales. Whether spinning like propellers or swarming like miniature armies, microbes have evolved diverse and ingenious ways to move through the world.
Understanding how microbes move helps scientists develop new technologies, fight infections, and explore the possibilities of life in extreme environments.
About the author:
Antonella Colque is a postdoctoral researcher at the Dep. of Clinical Microbiology, Rigshospitalet, Denmark. Her research focuses on how microbial communities adapt to different environments, with particular interest in mechanisms that impact human health. She is driven by the opportunity to contribute to projects with real-world clinical impact. Passionate about science communication, Antonella enjoys making complex scientific topics accessible and engaging for all audiences.