Functional genomic analysis of Vreelandella zhaodongensis BS253: a new isolate from hypersaline lakes from Brazilian Pantanal

Abstract Natural ecosystems harbor an immense diversity of microorganisms whose metabolic capabilities remain unexplored. Therefore, the investigation of microbial life in diverse environments can reveal bacteria with unique physiological and biochemical traits, which may be useful for biotechnological applications. In this study, we report the complete genome sequencing and functional characterization of isolate BS253, isolated in a hypersaline alkaline lake from Brazil’s Pantanal region. Using a hybrid sequencing strategy combining Oxford Nanopore long reads and Illumina short reads, we assembled a circular chromosome of 3.76 Mb and two plasmids. Phylogenetic and comparative genomic analyses identified the isolate as Vreelandella zhaodongensis . Digital DNA-DNA hybridization (76.4%) and ANI (96.83%) values supported the designation of BS253 as a strain of V. zhaodongensis . Genome mining revealed genes potentially associated with salt and alkali tolerance, hydrocarbon and plastic degradation, and the biosynthesis of secondary metabolites. Phenotypically, BS253 is a moderately halophilic, facultatively anaerobic, Gram-negative rod that also exhibits emulsifying activity (55.1%) under defined culture conditions. These findings highlight strain BS253 as a metabolically versatile extremophile and a promising candidate for future studies in environmental and industrial biotechnology.