Resuscitation of viable but nonculturable microorganisms: A highly promising strategy for enhanced bioremediation

The viable but non-culturable (VBNC) state is a common phenomenon through which microorganisms respond to stress to ensure long-term survival. To date, more than 100 microbial species have been reported to enter the VBNC state under various stressful conditions. In the VBNC state, cells undergo morphological, physiological, and genetic changes, with the mechanisms of VBNC state formation differing among microbial species and stressful conditions. Although the VBNC state has been extensively investigated in the fields of medicine and food safety, research on the VBNC state of pollutant-degrading microorganisms remains limited. Mounting evidence has confirmed the existence of the VBNC state in microorganisms capable of degrading polychlorinated biphenyls (PCBs) and phenol. The resuscitation of VBNC microorganisms, which represent a significant portion of microbial resources, is crucial for the effective microbial remediation of polluted environments. This review provides a comprehensive summary of the formation, characteristics, and mechanisms of the VBNC state in microorganisms. It also outlines various methods for resuscitating VBNC bacteria, with a specific focus on resuscitation-promoting factors (Rpfs). Importantly, from the perspective of environmental bioremediation, this review highlights the potential of VBNC state bacteria, the application of Rpfs in resuscitating VBNC bacteria in polluted environments, and the feasibility of utilizing resuscitated strains as inoculants for environmental bioremediation.