For a long time, it wasn’t clear whether non-photosynthetic bacteria were also subject to the dictates of circadian rhythms, and this has long been a mystery to scientists. Now, in a first-of-its-kind discovery, scientists have found that non-photosynthetic bacteria have a biological or internal daily clock similar to the same rhythms that control many other life forms such as plants, animals and even humans.
The new research, published in the journal Science Advances on January 8, answers an old biological question that could have major implications for the timing of drug use, biotechnology, and how to develop scientific solutions to protect crops.
The daily hour
The biological clock enables the organism to anticipate the daily environmental changes compatible with the day and night cycle and to adjust its biology and behavior accordingly. This phenomenon has been discovered in most living organisms, and its duration is about 24 hours (the solar day of the Earth now) for the majority of them, and these rhythms or timing mechanisms are found inside cells, and external signals such as daylight and temperature are used to synchronize biological clocks with their environment.
Although bacteria account for 12% of the planet’s biomass, little is known about their biological clocks, which were previously discovered only in bacteria that use light to create chemical energy, but non-photosynthetic bacteria have remained a mystery in this regard.
In this international study, researchers discovered circadian rhythms in the Bacillus subtilis bacteria, which are found in the soil, and form an internally protective spore that tolerates unfavorable environmental conditions.
Reporting on luciferase
The team applied a technique called luciferase reporting, which involves adding an enzyme that produces bioluminescence that allows researchers to visualize the extent of the gene’s activity within an organism. They focused on two genes: first, a gene called ytvA that encodes blue light receptors and secondly an enzyme called KinC that is involved in stimulating the formation of biofilms and germs in bacteria.
Then they observed gene levels in perpetual darkness compared to cycles of 12 hours of light and 12 hours of darkness. They found that the pattern of levels of YTVA expression was modified according to the cycle of light and darkness, with levels increasing during darkness and decreasing in light.
It took several days for a stable pattern to emerge, and the researchers observed how the pattern could be reversed if conditions reversed. These two observations are common features of circadian rhythms and their ability to “drift” into environmental cues.
Then the researchers conducted similar experiments using daily changes in temperature, and found that the gene rhythms were modified in a way that matches circadian rhythms, not just turning on and off in response to temperature.
Bacteria determine time!
“We found for the first time that non-photosynthetic bacteria could tell time,” said lead author Martha Miro, of Ludwig Maximilians University in Munich, in a press release for The John Innes Center, UK.
Kos Kovacs – co-author from the Technical University of Denmark – says in the same press release, “Bacillus subtilis is used in various applications ranging from the production of laundry detergent to protecting crops, in addition to its recent exploitation as a probiotic (nutritional supplement) for humans. Animal, and therefore its biological clock engineering will culminate in various fields of biotechnology. ” “Our study opens the doors to the investigation of circadian rhythms through bacteria,” adds Dr. Anthony Dodd of the John Innes Center.
The implications of this research can be used to answer questions related to daily timing, such as: Is the timing of exposure to bacteria important to cause infection, can industrial biotechnology processes be improved by taking time into account, and then is the timing of antibacterial treatment important?