Quorum-sensing systems trigger catalase expression to reverse the oxyR deletion-mediated VBNC state in Salmonella typhimurium

In this study, conditioned media containing autoinducer collected from the wild type strain can restore the growth of low concentrations of the oxyR mutant strain on LB plates, and S. typhimurium collected from the plate has higher catalase activity than that from the broth, suggesting that a quorum-sensing system can trigger catalase expression to resuscitate the organism from the VBNC state independent of the OxyR regulon. We discovered a novel catalase (STM14_2049, Cat) whose expression is strictly concentration-dependent. The purified Cat protein has obvious catalase activity in vitro and in vivo and can restore the growth of the low concentration oxyR mutant strain. Thus, we believed Cat plays a role in VBNC resuscitation process. By understanding this mechanism, we can further understand the antioxidation and quorum-sensing systems in Salmonella typhimurium.
Source: Research in Microbiology - Category: Microbiology Source Type: research