# The Viable but Non-Culturable (VBNC) State, a Poorly Explored Aspect of Beneficial Bacteria
## 2 Bacterial Species Entering the VBNC State  
A substantial portion of the bacterial species known to enter the VBNC state include human pathogens such as _Campylobacter_ spp., _Escherichia coli_ (EHEC strains), _Francisella tulareis_, _Helicobacter pylori_, _Legionella pneumophila_, _Listeria monocytogenes_, _Mycobacterium tuberculosis_, _Pseudomonas aeruginosa_, several species of _Salmonella_ spp., _Shigella_ spp., and numerous pathogens from the genus _Vibrio_ sp., with _Vibrio_ vulinficus_ being one of the most studied in terms of the VBNC state [2].  
Figure 1: CFU/mL (log) of _Pseudomonas putida_ KT2440 under desiccation stress at 18 days after the beginning of desiccation (DABD), in the presence (green bars) and absence (blue bars) of trehalose. Adapted from [PERSON] et al., 2019 [4].  
The list of pathogenic bacteria that can adopt the VBNC state as a survival strategy includes pathogens affecting not only humans but also animals, such as _Photobacterium damselae_, infecting fish [8]; _V. cuhificus_, an eel pathogen [9], and _V. shiloi_, which causes the bleaching of corals [10; 11]. Several plant pathogens have been described--for example, _Ralstonia solanacearum_ in tomato plants [12]; _Xanthomonas axonopods_ colonizing graprefruit plants [13]; _Ervinia anylovora_ infecting ripe apples [14]; _Pseudomonas syringae_ in tomato, cereals, almond, cherry, and plum plants; _Acidovorax citrulli_ infecting a wide variety of Cucurbitaceae, causing bacterial spot disease (bacterial fruit blotch) [15]; and _Agrobacterium tumefaciens_, which causes tumors in different dicyledons.  
Since the publication of [PERSON]'s et al. study [5] more than 30 years ago, a substantial body of research around the world has focused on documenting the occurrence of the VBNC state in different bacterial species [2; 4; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26].  
To date, approximately 101 bacterial species spanning 50 different genera have been reported to exhibit the VBNC phenomenon [2; 18; 25; 26; 27]. In the present review, we analyze the beneficial bacterial species where the VBNC status has been reported and the importance of this within their potential in areas such as biotechnology, agriculture, and the food industry. For this review, a comprehensive search of publications was conducted utilizing Web of Science, PubMed, and Google Scholar. The research by [PERSON] (2010) [27] and [PERSON] (2019) [25], who previously compiled a list of bacteria entering the VBNC state under specific conditions, served as a reference. The search terms included \"viable but non-culturable bacteria\" or \"viable but non-culturable state\" or \"beneficial bacteria in VBNC state\". A specialized search was conducted for each bacterial species included in the review. This involved using the scientific name of each species along with specific terms such as \"biotechnological applications\", \"beneficial applications\", \"VBNC\", or \"viable but non-culturable state in...\". The bibliographic search encompassed the period between 1982, the year in which the concept of the viable but non-culturable state was introduced by [PERSON] [2; 5], and 2023.