Dormant Bacteria Can Still Calculate When To Return To Life
Some dormant bacteria can still calculate when to return to lifeafter going into a state of dormancy where their lifefunctions cease when circumstances get a little more favorable. These undead cells, which are also called spores, can survive high pressure, heat, and even the harsh conditions of space while in this state, and they can stay in this state for a very long time.
According to a recent study, these bacteria simply count how frequently they come into contact with nutrients to determine when it is time to revive or germinate. Even though these bacteria spores are in a dormant stage, they are still able to gather information about their surroundings.
Researchers found that spores slowly release the electrochemical energy they have stored inside them. This lets them know when it's time to start living again, even if there aren't any clear signs from the outside.
According to Gürol Süel, a microbiologist at the University of California, San Diego,
They appear to have literally no measurable biological activity.- Gürol Süel, a microbiologist at the University of California, San Diego
Since positively charged potassium atoms in the center of spores can move around without the cell needing energy, Süel and his colleagues thought that potassium may play a role in waking up the cells. Therefore, the group subjected B. subtilis spores to nutrients and employed fluorescent dyes to monitor the efflux of intracellular potassium.
The thinking undead: How dormant bacteria calculate their return to life
The core's electrical charge became increasingly negative as more potassium left it during each exposure. When the central part of the spore became negatively charged enough, germination happened, like when the cork on a bottle of champagne pops.
To germinate, different spores need different numbers of exposures, much like different corks need different amounts of twisting to open. Experiments showed that spores that couldn't move potassium around didn't change their electric charge much, even though they had plenty of food, so they were less likely to "pop" back to life.
From the timing of brain cells' zipping out messages to each other to the snapping of a Venus flytrap, changes in a cell's electrical charge play a crucial role throughout the tree of life. Süel is thrilled by the discovery that spores utilize electrical charges to program their alarms.
"You want to identify principles in biology, processes that traverse systems, fields, and frontiers," he adds. The unusual and extreme biology of spores is fascinating, but that's not all they're good for. Some are quite harmful and can result in food poisoning or even anthrax. Because spores are immune to many drugs, learning how they germinate could lead to a strategy for eliminating them once and for all.
However, there are still a lot of questions that need to be answered regarding how spores start to develop, such as whether or not they can reset their potassium count.
According to Kaito Kikuchi, a biologist now at Reveal Biosciences in San Diego who conducted the work while at University of California, San Diego,
We really are in the beginnings of trying to fill in that black box.- Kaito Kikuchi, a biologist now at Reveal Biosciences in San Diego
However, finding out how spores are able to detect their environment while they are essentially dead is an intriguing place to start.