Very little is known about many microbes, despite their widespread existence and billions of years of evolution. This contains the complete genus of bacteria known as Omnitrophota, which are nanosized. These bacteria are widespread worldwide and were just recently found using short DNA pieces. However, their biology is still poorly understood. Until now, that is. An multinational team of researchers conducted the first large-scale analysis of more than 400 newly sequenced and existing Omnitrophota genomes, revealing new information about their biology and behavior. The team’s findings are described in the journal Nature Microbiology.
UNLV microbiologist and research co-author Brian Hedlund said, “We now have the most comprehensive understanding to date of the biology of an entire phylum of microbes and the remarkable role they play in the Earth’s ecosystems. It’s wonderful to discover more about organisms that predate plants and animals and have essentially been concealed under our noses because there are only a limited number of primary lineages of life on our planet. The challenge with Omnitrophota is that they are still mainly regarded as microbe “dark matter,” meaning they can still be found in nature but are not yet able to be grown as a single species in lab experiments. Only two species—and only recently—have been examined under the microscope.
Researchers examined 349 already existing and 72 newly mapped Omnitrophota genomes to provide a complete picture of their biology. This includes a study of data that was made publically available as well as fresh samples that were gathered from springs, freshwater lakes, wastewater, geothermal regions, and other global locations. The study found that Omnitrophota are among the tiniest known species, with the majority of them measuring less than 450 nanometers. Also, they had genetic traits suggestive of symbiosis, suggesting that they may have had high metabolic rates as predators or parasites of other bacteria.
In fact, Omnitrophota were overactive when isotope absorption was assessed as a surrogate for metabolic activity. ” Despite how little we all knew about Omnitrophota, microbial ecologists have long used them as examples. With this study, Cale Seymour, a recent master’s graduate from UNLV, served as the study’s lead author. “Our aim was to finally bring this lineage out of the shadows,” he stated. “We are getting closer to our aim of bringing them into the light and developing them in the lab the more we understand about their energy conservation routes and potential lives.”