The Viable but Non-Culturable (VBNC) State, a Poorly-Explored Aspect of Beneficial Bacteria

Abstract

Many bacteria have the ability to survive in challenging environments; however, they cannot grow on standard culture media, a phenomenon known as the Viable but Non-Culturable (VBNC) state. Bacteria commonly go into the VBNC state under nutrient-poor environments or under stressful conditions. This review explores the concept of the VBNC state, providing insights into the beneficial bacteria known to employ this strategy. The investigation covers different chemical and physical factors that can induce the latency state, cell features, and gene expression observed in cells in the VBNC state. The revision also covered the significance and applications of beneficial bacteria, methods for evaluating bacterial viability, the ability of bacteria to persist in environments associated with higher organisms, and the factors that facilitate the return to the culturable state. Knowledge about beneficial bacteria capable of entering the VBNC state remains limited, however, beneficial bacteria in this state could face adverse environmental conditions, and return to culturable state when conditions become suitable and continue to exert their beneficial effects. Likewise, this unique feature positions them as potential candidates for healthcare applications, such as the use of probiotic bacteria to enhance human health, applications in industrial microbiology for the production of prebiotics, functional foods, and in the beer and wine industry. Moreover, their use in formulations to increase crop yield and for bacterial bioremediation offers an alternative pathway to harness their beneficial attributes.