A novel salt-tolerant alpha-proteobacterium, designated SALINAS58T, was isolated from Santa Engracia hypersaline spring water in the Añana Salt Valley, Álava, Spain. The isolate was Gram-negative, aerobic, non-motile, catalase-positive, oxidase-negative, rod-shaped and formed orange colonies on marine agar. Optimal growth was observed at pH 6.0–6.5, at 30 °C and in the presence of 1% (w/v) NaCl. The main cellular fatty acids (>20%) were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c). The major respiratory quinone was ubiquinone Q-10 and the major polar lipids detected were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidilglycerol, four unidentified glycolipids and one unidentified phospholipid. Strain SALINAS58T had the highest 16S rRNA gene sequence similarity to Altererythrobacter marensis MSW-14T (96.6%), Altererythrobacter aquaemixtae JSSK-8T (96.5%) and Pontixanthobacter luteolus SW-109T (96.5%) followed by Altererythrobacter atlanticus 26DY36T (96.4%). Results of the phylogenetic analysis, based on 16S rRNA gene sequences, and phylogenetic approaches based on whole genome nucleotide differences, showed that strain SALINAS58T could be distinguished from recognized species of the genus Altererythrobacter . The genomic DNA G+C content was 61.4 mol%. Digital DNA–DNA hybridization, average nucleotide identity and average aminoacid identity values between the genome of strain SALINAS58T and A. marensis MSW-14T were 18.4, 73.1 and 68.1%, respectively. Based on data from this polyphasic characterization, strain SALINAS58T (=CECT 30029T=LMG 31726T) is considered to be classified as representing a novel species in the genus Altererythrobacter , for which the name Altererythrobacter muriae sp. nov. is proposed.

During a prokaryotic diversity study in Añana Salt Valley, a new Rhodobacteraceae member, designated ASV31T, was isolated from Santa Engracia spring water. It was extremely halotolerant, tolerating up to 23% NaCl, and facultatively alkaliphilic, growing at pH 6.5–9.5 (optimum at 7.0–9.5). The isolate was a Gram-negative, rod-shaped, aerobic and non-motile bacterium that formed beige-to-pink colonies on marine agar. According to a 16S rRNA gene-based phylogenetic analysis, strain ASV31T forms a distinct branch of the family Rhodobacteraceae, with Thioclava pacifica DSM 10166T being its closest type strain (95.3%). This was confirmed with a phylogenomic tree and the values of ANI (73.9%), dDDH (19.3%), AAI (63.5%) and POCP (56.0%), which were below the genus/species level boundary. Additionally, an ability to degrade aromatic compounds and biosynthesise secondary metabolites was suggested by the genome of strain ASV31T. Distinguishing fatty acid profiles and polar lipid content were also observed. The genome size was 3.6 Mbp, with a DNA G+C content of 65.7%. Based on the data obtained, it was considered that strain ASV31T (=CECT 30309T = LMG 32242T) represents a new species of a new genus in the family Rhodobacteraceae, for which the name Anianabacter salinae gen. nov., sp. nov. is proposed.

The Añana Salt Valley in Spain is an active continental solar saltern formed 220 million years ago. To date, no fungal genomic studies of continental salterns have been published, although DNA metabarcoding has recently expanded researchers’ ability to study microbial community structures. Accordingly, the aim of this present study was to evaluate fungal diversity using the internal transcribed spacer (ITS) metabarcoding at different locations along the saltern (springs, ponds, and groundwater) to describe the fungal community of this saline environment. A total of 380 fungal genera were detected. The ubiquity of Saccharomyces was observed in the saltern, although other halotolerant and halophilic fungi like Wallemia, Cladosporium, and Trimmatostroma were also detected. Most of the fungi observed in the saltern were saprotrophs. The fungal distribution appeared to be influenced by surrounding conditions, such as the plant and soil contact, cereal fields, and vineyards of this agricultural region.