Effect of (Host Factor for RNA Phase Q Replicase) on Environmental Tolerance of Under Simulated Microgravity.

During space flights, opportunistic pathogens carried by astronauts may change their biological characteristics under weightless conditions, potentially affecting the health of astronauts. Simulated microgravity (SMG) has been reported to influence the environmental tolerance, which is related to 's environmental tolerance. But the underlying mechanisms remain unclear. Host factor for RNA phage Q replicase () is an RNA molecular chaperone protein found in bacteria. In this study, we discovered that expression in increases under SMG through transcriptome sequencing analysis. We knocked out hfq in to establish a - strain to investigate the effect of on the environmental tolerance of under SMG, and observed changes in Coproporphyrinogen III dehydrogenase () and RNA polymerase sigma factor (), which are related to the environmental tolerance of . Results showed that the growth level of - was significantly lower than that of the wild-type strain under SMG. enhances its tolerance to oxidative stress through the - pathway under SMG. After SMG exposure, 's tolerance to high temperatures and acidic environments changed, but these changes were not mediated by the - pathway; instead, they may act synergistically. This study provides a foundation for preventing and controlling opportunistic pathogenic bacterial infections during aerospace missions.