Cyanobacteria are single-celled microbes that can photosynthesize, and they helped generate Earth's atmosphere to make complex life possible. Cyanobacteria still help to maintain life on Earth, and live in nearly all marine environments including the frozen lakes of Antarctica and tropical oceans. A new study has shown that cyanobacteria can transition from disorganized states into woven patterns that generate biomats. The findings have been reported in Nature Communications Physics.
“[Cyanobacteria] produce the lion's share of the oxygen that we breathe and form one of the bases of the food chain in the ocean. Understanding how they build their biomats can help us learn about their role in a variety of ecosystems, provide clues about ancient environments where life first evolved, and also inspire new materials for human use," noted co-corresponding study author Dr. Marco Mazza of Loughborough University.
One cyanobacterium is only about one to thirty micrometers (µm) in diameter, but the biomats they make are large enough to be seen with the eye. The mats appear as algae in riverbeds, on seashores, and in stagnant water. A biomat about the size of a standard sheet of paper can form within hours, and may be composed of hundreds of millions of cyanobacteria.
When an influx of nutrients fuels the rapid growth of these mats, they are known as algae blooms, which can pose many problems to marine life and water systems.
Filamentous cyanobacteria create biomats to boost their survival; the mats provide stability and protection, and the cyanobacteria in them can act as one unit. The mats can reorganize into a new structure when conditions such as light, water flow, or nutrient levels change. This adaptability allows them to survive even when challenged.
The researchers suggested some features of cyanobacteria may help us; we could make better materials or clothing, for example, that could actually adapt to changing environmental conditions. We have to decipher the biomat phenomenon first, however.
In this work, the researchers grew cyanobacteria called Oscillatoria lutea and analyzed it with a laser scanning microscope to reveal interactions between filaments, and how the varying densities were self-organizing into the biomat. The density and mobility of cyanobacteria were found to play a major role in how biomats formed. The patterns with the most stability were made up of cyanobacteria that were very dense and highly motile. Filament length also affected patterns, with shorter filaments making patterns that were less organized and longer filaments generating arrangements with more order and alignment.
“This work shows how the remarkably complex behaviors of biomats, the Earth’s earliest expressions of multicellular life, can be explained by a few simple rules," said co-corresponding study author Professor Lucas Goehring of Nottingham Trent University.
“Ultimately, we hope to further the understanding of one of the most crucial members of the ecosystem whose ability to shape their environment is astonishing," noted first study author Dr Jan Cammann, a Research Associate in Mathematics at Loughborough University.
This work may help us understand and deal with problematic bacterial colonies like biofilms as well. “This knowledge is critical given the central role of biofilms in various processes, such as human infections, environmental degradation, and bioengineering," noted Cammann.
Sources: Nature Communications Physics, Nottingham Trent University
