Exploring the taxonomical and functional profile of As Burgas hot spring focusing on thermostable β-galactosidases

Abstract

In the present study we investigate the microbial community inhabiting As Burgas geothermal spring, located in Ourense (Galicia, Spain). The approximately 23 Gbp of Illumina sequences generated for each replicate revealed a complex microbial community dominated by Bacteria in which Proteobacteria and Aquificae were the two prevalent phyla. An association between the two most prevalent genera, Thermus and Hydrogenobacter, was suggested by the relationship of their metabolism. The high relative abundance of sequences involved in the Calvin–Benson cycle and the reductive TCA cycle unveils the dominance of an autotrophic population. Important pathways from the nitrogen and sulfur cycle are potentially taking place in As Burgas hot spring. In the assembled reads, two complete ORFs matching GH2 beta-galactosidases were found. To assess their functional characterization, the two ORFs were cloned and overexpressed in E. coli. The pTsbg enzyme had activity towards o-Nitrophenyl-β-d-galactopyranoside (ONPG) and p-Nitrophenyl-β-d-fucopyranoside, with high thermal stability and showing maximal activity at 85 °C and pH 6, nevertheless the enzyme failed to hydrolyze lactose. The other enzyme, Tsbg, was unable to hydrolyze even ONPG or lactose. This finding highlights the challenge of finding novel active enzymes based only on their sequence.

Prokaryotes of renowned Karlovy Vary (Carlsbad) thermal springs: phylogenetic and cultivation analysis

“…Figure 1 depicts the presence of up to 19% as-yet-unclassified, potentially novel microbial taxa at the class level. Despite this, the set of 50 most abundant unique ASVs from each spring contains genera that are commonly reported in literature on similar aquatic habitats, such as the genera Desulfacinum and Thiomonas [ 68 ], Sulfuricurvum [ 69 ], Thermoflexus [ 70 ], Hydrogenobacter [ 71 ], Sideroxydans [ 72 ], Halothiobacillus , or Sulfurimonas [ 73 ], some of which in similar relative abundances compared to our dataset. Genera known to be involved in sulfate reduction [ 74 ] and iron oxidation [ 75 ] were found mainly in thermal spring P, which is also the spring with the highest iron and sulfate cation concentrations of the examined thermal springs (Additional file 1 : Table S1).…”

Unraveling the bacterial diversity of Cangar Hot Spring, Indonesia by Next Generation Sequencing of 16S rRNA gene

“…Meanwhile, the high abundance of Bacteroidetes phylum was observed in Badi Anhoni hot spring, India (55°C, pH 7.8) and Phusang hot spring, Thailand (38°C, pH 7.3) (Bumrungthai et al 2020, Saxena et al 2017. Bacteroidetes were less prevalent in hot springs with a temperature above 70°C (i.e., Burgas hot spring, Spain; Soldhar hot spring, India; and Sungai Klah, Malaysia (80°C) (Chan et al 2015, DeCastro et al 2021.…”

“…In this study, NGS was employed to perform 16S rRNA metagenomic analysis for unraveling bacterial diversity in Cangar Hot Spring, especially pathogenic bacteria and bacteria with potential commercial applications In this study, the dominant components of the bacterial community structure of Cangar Hot Spring were Gram-negative bacteria, i.e., members of Proteobacteria, Bacteroidetes, and Chloroflexi phyla (>89% OTU). The dominance of Proteobacteria phylum was also reported from similar studies using 16S rRNA analysis in hot springs from a geographically distant area with moderate to high temperatures (37-95°C), such as Ayer Hangat hot spring, Malaysia (45°C, pH 7.1); Coamo hot spring, Puerto Rico (47°C, pH 8.2); Burgas hot spring, Spain (66.3°C, pH 7.6); Hammam Essalihine hot spring, Algeria (70°C, pH 7.3); and Soldhar hot spring, India (95°C) (Adjeroud et al 2020, Chan et al 2017, DeCastro et al 2021, Padilla-Del Valle et al 2017. Meanwhile, the high abundance of Bacteroidetes phylum was observed in Badi Anhoni hot spring, India (55°C, pH 7.8) and Phusang hot spring, Thailand (38°C, pH 7.3) (Bumrungthai et al 2020, Saxena et al 2017.…”

Stress Dependent Biofilm Formation and Bioactive Melanin Pigment Production by a Thermophilic Bacillus Species from Chilean Hot Spring

“…Thermophiles, optimally growing at ~55 • C, are generally found in the extreme temperature environments of hot springs fumaroles, hydrothermal vents, geysers, or deserts [20]. As well as high temperatures, these extreme habitats also often have extreme pH or high salt concentrations [20].…”

“…Thermophiles, optimally growing at ~55 • C, are generally found in the extreme temperature environments of hot springs fumaroles, hydrothermal vents, geysers, or deserts [20]. As well as high temperatures, these extreme habitats also often have extreme pH or high salt concentrations [20]. As discussed earlier, the study of microorganisms inhabiting such ecosystems is interesting from a biotechnological point of view, as they produce several bioactive and thermostable molecules.…”