Due to high salinity, low pH and anoxic conditions, brine pools are one of the most extreme habitable environments on Earth making them home to unique extremophile microbial assemblages. These assemblages are an oasis of biodiversity in an otherwise bathyal desert. Previous work focused on characterizing the microbial community inhabiting the brine body itself while only minimally addressing the associated sediments. No other study to date has attempted to realize vertical stratifications within the brine-associated sediment regime. This study proposes there are in fact multiple microbial ecosystems present within brine pool systems suggesting that focusing exclusively on the brine underestimates the full extent of biodiversity. We further sought to determine whether vertical stratifications exist within the scope of these ecosystems. DNA was extracted from three brine samples as well as five sediment cores taken in and around the newly discovered NEOM brine pool located in the Gulf of Aqaba. This study utilizes 16S rRNA genomics and bioinformatics software including Qiime2 and FAPROTAX to characterize the microbial assemblages present within the brine and associated sediments. Results reveal that the NEOM brine pool consists of three microbial ecosystems that are taxonomically distinct from one another. These can be broadly categorized as the brine itself, beneath-brine sediments and brine-adjacent sediments. Furthermore, vertical stratifications were identified within the brine-adjacent sediments. These results indicate that the biodiversity present in unique brine pool communities is even higher than previously thought potentially opening the door for new research avenues in these environments.
