Microbial community structure and shift pattern of industry brine after a long-term static storage in closed tank

Abstract

Brine from Dingyuan Salt Mine (Anhui, China), an athalassohaline hypersaline environment formed in the early tertiary Oligocene, is used to produce table salt for hundreds of millions of people. However, halophiles preserved in this niche during deposition are still unknown. Here, we employed cultivation and high-throughput sequencing strategies to uncover the microbial community and its shift after a long-term storage in the brine collected from Dingyuan Salt Mine. High-throughput sequencing showed (1) in the fresh brine (2021), Cyanobium_stocktickerPCC-6307 spp. (8.46%), Aeromonas spp. (6.91%) and Pseudomonas spp. (4.71%) are the dominant species in bacteria while Natronomonas spp. (18.89%), Halapricum spp. (13.73%), and Halomicrobium spp. (12.35%) in archaea; (2) after a 3-year-storage, Salinibacter spp. (30.01%) and Alcanivorax spp. (14.96%) surpassed Cyanobium_stocktickerPCC-6307 spp. (8.46%) becoming the dominant species in bacteria; Natronomonas spp. are still the dominant species, while Halorientalis spp. (14.80%) outnumbered Halapricum spp. becoming the dominant species in archaea; (3) Alcanivorax spp. and Halorientalis spp. two hydrocarbons degrading microorganisms were enriched in the brine containing hydrocarbons. Cultivation using hypersaline nutrient medium (20% NaCl) combined with high-throughput 16S rRNA gene sequencing showed that (1) the biomass significantly increased while the species diversity sharply declined after a 3-year-storage; (2) Halorubrum spp. scarcely detected from the environment total stocktickerDNA were flourishing after cultivation using AS-168 or NOM medium; (3) twelve possible new species were revealed based on almost full-length 16S rRNA gene sequence similarity search. This study generally uncovered the microbial community and the dominant halophiles in this inland athalassohaline salt mine, and provided a new insight on the shift pattern of dominant halophiles during a long-term storage, which illustrated the shaping of microorganisms in the unique environment, and the adaptation of microbe to the specific environment.

Vertical organization of microbial communities in Salineta hypersaline wetland, Spain

“…The Geothermobacter genus, iron-reducing bacterium (Gomez-Saez et al, 2017), and the Desulfovermiculus, sulfate-reducing bacterium (Nigro et al, 2020) are usually found in hypersaline environments where they play a key role in iron and sulfur cycling. The archaeal phylum Halobacteriota was dominated by Halapricum (6.1%), Halorubrum (3.6%), and Natronomonas (2.2%) genera (representing, respectively, 12, 7, and 4.3% of the phylum), isolated in hypersaline ecosystems where they often represent the dominant archaeal taxa (Tu et al, 2022). Halorubrum and Natronomonas are known as aerobes (Mora-Ruiz et al, 2018), while Halapricum is a sulfate-reducing archaeon (Sorokin et al, 2022).…”