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

Abstract

Background The extreme conditions of thermal springs constitute a unique aquatic habitat characterized by low nutrient contents and the absence of human impacts on the microbial community composition. Thus, these springs may host phylogenetically novel microorganisms with potential use in biotechnology. With this hypothesis in mind, we examined the microbial composition of four thermal springs of the world-renowned spa town of Karlovy Vary (Carlsbad), Czechia, which differ in their temperature and chemical composition. Results Microbial profiling using 16S rRNA gene sequencing revealed the presence of phylogenetically novel taxa at various taxonomic levels, spanning from genera to phyla. Many sequences belonged to novel classes within the phyla Hydrothermae, Altiarchaeota, Verrucomicrobia, and TA06. Cultivation-based methods employing oligotrophic media resulted in the isolation of 44 unique bacterial isolates. These include strains that withstand concentrations of up to 12% NaClw/v in cultivation media or survive a temperature of 100 °C, as well as hitherto uncultured bacterial species belonging to the genera Thermomonas, Paenibacillus, and Cellulomonas. These isolates harbored stress response genes that allow them to thrive in the extreme environment of thermal springs. Conclusions Our study is the first to analyze the overall microbial community composition of the renowned Karlovy Vary thermal springs. We provide insight into yet another level of uniqueness of these springs. In addition to their unique health benefits and cultural significance, we demonstrate that these springs harbor phylogenetically distinct microorganisms with unusual life strategies. Our findings open up avenues for future research with the promise of a deeper understanding of the metabolic potential of these microorganisms.

Ecological versatility and biotechnological promise: Comprehensive characterization of the isolated thermophilic Bacillus strains

“…The universal upper limit of growth at 73˚C across all species underlines a potential threshold for thermophilic bacterial survival and function. The variation in optimal growth temperatures, with species like B. stearothermophilus thriving at 56˚C while others like TBS5 and TBS35 prefer higher temperatures, reflects their ecological adaptability [7,8,19]. The ability of TBS35 and TBS40 to grow at a lower minimum temperature of 37˚C could indicate a broader ecological niche or specific adaptive mechanisms [20][21][22].…”

“…The main objective of this study was to extend previous research and analyze thermophilic Bacillus strains that have been isolated on a large scale. We focused on understanding their growth conditions, oxygen requirements, colony appearance, and enzyme profiles [ 7 , 8 ].…”

Compost, plants and endophytes versus metal contamination: choice of a restoration strategy steers the microbiome in polymetallic mine waste

“…The V4-V5 hypervariable region of the 16S rRNA gene was amplified using the 515 forward (5′-GTGYCAGCMGCNGCGG-3′) and 926 reverse primers (5′-CCGYCAATTYMTTTRAGTTT-3′) [ 56 ]. ITS2 region was amplified using 5.8S_Fun forward primer (5′-AACTTTYRRCAAYGGATCWCT-3′) and ITS4_Fun reverse primer (5′-AGCCTCCGCTTATTGATATGCTTAART-3′) [ 57 ].…”

Reaching unreachables: Obstacles and successes of microbial cultivation and their reasons

“…Applying this strategy, Kapinusova et al (2022) isolated over 100 bacterial species, including several novel species of Alphaproteobacteria , Betaproteobacteria , Flavobacteriia, and even a member of a novel genus of Thermoleophilia ( Kapinusova et al, 2022 ). A similar strategy combined with a prolonged incubation time was used for the culturomics of the world-renowed thermal springs of Karlovy Vary ( Smrhova et al, 2022 ) and led to the acquisition of several thermotolerant strains of the Bacillota phylum and isolation of novel microorganisms of Bacilli , Gammaproteobacteria , and Actinomycetia classes. The dilution-to-extinction technique, based on the cultivation of soil oligotrophic microorganisms on media containing 100-fold diluted nutrients, resulted in the isolation of a wide spectrum of the most abundant soil representatives, and also of members of two previously undescribed actinobacterial lineages ( Bartelme et al, 2020 ).…”