Sometimes procrastination pays off. When the environment becomes too stressful, many bacteria pack part of their interior into very tough packets called spores and shut down waiting for the situation to improve.How do these dead-looking spots sense optimal conditions for resurrection? chemistry It turns out that bacterial spores can decide when to wake up by setting an electrical alarm.
Starvation, radiation, scorching heat, freezing cold, and even the vacuum of space pose no particular problem for spores. But otherwise they seem “useless,” says study author Gürol Süel, a biophysicist at the University of California, San Diego. They will be pronounced dead on arrival,” he says.
Spores are indestructible only while dormant. So you need to avoid waking up (or “germinating”) in bad conditions, says Peter Setlow, a biochemist at the University of Connecticut who was not involved in the study. you are dead “
This study reveals one way spores make that decision. To form a spore, the bacterium makes a copy of its DNA, packs it into a small compartment, wraps the whole thing in a protective coat, bursts and releases the spore (and dies in the process). The spore reserves that form charge the potassium ions, creating a “biological capacitor” that stores electrical energy, he says. Each time a spore encounters a nutrient, it leaks out some of its potassium stores and dissipates some of its charge. increase.
“This is a big step forward in this area,” says Setlow. “It brings a whole new way of thinking about germination.” Knowing how spores “count” nutrients could improve food safety. Spore-forming bacteria can survive harsh sterilization procedures and can revive and cause food poisoning. Dormancy also helps disease-causing bacteria evade attack. “There’s a lot of interest in ways to quickly germinate spores,” he adds, because waking them up early could improve treatment.
The findings suggest that ion countdowns may be fundamental to life on Earth, says Süel. Neurons also count electricity to know when to fire. The researchers found that the formula describing neurons also predicted spore behavior well. Venus flytraps use electrical countdowns to snap shut, and all cells utilize ion currents to process energy.
“These potentials are not a recent invention. They are billions of years old,” says Süel. “What other aspects of biology can we better understand by keeping in mind that these charged ions are everything, not just gene expression or proteins or DNA?”
