Bacteria hyperpolarize in response to oxygen drop

Aerobic bacteria utilize oxygen as a vital electron acceptor to generate a membrane potential across their cell membranes. However, the precise mechanisms behind maintaining this potential during fluctuations in oxygen levels remain unclear. Researchers have now discovered that bacteria indeed hyperpolarize when oxygen availability decreases.

By focusing on Bacillus subtilis and using computational modeling, they found that the degree of hyperpolarization directly correlates with the severity of electron acceptor deprivation. The researchers also identified potassium efflux as a key contributor to this response. By studying various mutant strains, they uncovered genes involved in potassium regulation and oxygen stress that play a role in hyperpolarization.

Surprisingly, they discovered that hyperpolarization is linked to faster growth rates, which are influenced by both the type of nutrients and spatial variability within bacterial colonies. Lastly, their findings reveal that bacteria subjected to oxygen shifts become more susceptible to antibiotics. These results highlight a shared mechanism between membrane potential changes and oxygen stress, suggesting a common response strategy employed by bacteria in the face of shifting oxygen availability.