The Marine Bacterial Genus Euzebya Is Distributed Worldwide in Terrestrial Environments: A Review

The advent of molecular tools, and particularly next-generation sequencing, has dramatically changed our knowledge of the diversity of microbial life on Earth. In recent decades, many studies on different terrestrial environments have described the intriguing diversity and abundance of Euzebyales/Euzebyaceae/Euzebya, yet its role in the geochemical cycle of elements is unknown. In addition, as far as we know, no Euzebya isolates have been obtained from terrestrial niches. In this review, it is shown that Euzebya and other haloalkaliphilic bacteria can thrive under harsh conditions, such as high concentrations of sodium and/or calcium, high electric conductivity and alkaline pH, highly variable temperatures, and water fluctuations. These conditions are quasi-extreme in the studied terrestrial environments. However, the culture media used so far for isolation have failed to reproduce the original conditions of these terrestrial ecosystems, and this is likely the reason why strains of Euzebya and other bacteria that inhabit the same niche could not be isolated. It is expected that culture media reproducing the environmental conditions outlined in this review could cope with the isolation of terrestrial Euzebya and other haloalkaliphilic genera.