Microflora Thermarum Atlas project: biodiversity in thermal
spring waters and natural SPA pools
F. Valeriani, C. Protano, G. Gianfranceschi, E. Leoni, V. Galasso, N. Mucci,
M. Vitali and V. Romano Spica
ABSTRACT
Thermal springs are natural environments present all over the world and their use represents a
social-economical resource with an impact on sanus per aquam (SPA) medical and wellness
applications. Physical-chemical and microbiological balances characterize these ecological niches
and their knowledge is essential to define water properties and support appropriate management.
This study is a pilot application of a larger research project, involving metagenomics and aimed to
fingerprint springs and map SPA biodiversity. Waters and their deposits were collected in six thermal
springs from the Lazio region in Italy. The phylogenic microbial profiles performed by Next Generation
Sequencing (NGS) analysis showed a clear separation between different springs. Statistical analyses
revealed correlations between the abundance of specific bacteria and environmental variables.
Temperature, Sodium and H2S levels appear to play a key role in influencing the microbiota. The
extension of this model to other springs will contribute to characterize and map the microbial
community in thermal springs, allowing associations with chemical-physical factors. Biodiversity is a
still underestimated property of thermal springs and a key element in several SPA applications. The
Atlas progress is shedding light on biotic and abiotic components in these ecological niches, opening
further perspectives for supporting appropriate use and management of thermal waters.
F. Valeriani
G. Gianfranceschi
V. Romano Spica (corresponding author)
Public Health Unit,
University of Rome ‘Foro Italico’,
P.zza L. De Bosis 6, 00135 Roma, Italy
E-mail: vincenzo.romanospica@uniroma4.it
C. Protano
M. Vitali
Department of Public Health and Infectious
Diseases,
Sapienza University,
Rome, Italy
E. Leoni
Unit of Hygiene, Public Health and Medical
Statistics, Department of Biomedical and
Neuromotor Sciences,
University of Bologna,
Bologna, Italy
V. Galasso
Scientific Direction,
Regina Isabella,
Ischia, Italy
N. Mucci
Department of Technological Innovations and
Safety of Plants,
Products and Anthropic Settlements, INAIL,
Rome, Italy
Key words | biodiversity, mfDNA, metagenomic, geochemistry, SPA, thermal spring waters
INTRODUCTION
Since ancient times, thermal springs were known and used
for health and social purposes, in natural or artificial pools
(Van Tubergen & Van Der Linden ). Nowadays, sanus
per aquams (SPAs) represent a worldwide resource with a
valuable impact for medical and wellness applications,
including hydro-balneotherapies, rehabilitation, physical
activity and recreational uses (Frosch ). However, a
more updated and rigorous approach is required to dis-
tinguish the different springs, provide evidences for
possible therapeutic properties or for the development of
bioactive products. Thermal springs are natural water
environments present all over the world (Mirete et al.
). These habitats comprise ecological niches, character-
ized by a unique microbial flora active within specific
chemical and physical balances (Marsh & Larsen ;
Yazdi et al. ). These unusual or even extreme environ-
ments can represent a major source of microbial diversity
and a potential for research and development in biotech-
nology (Trabelsi et al. ; Valeriani et al. a; Urbieta
et al. ). Moreover, knowledge on extremophiles inhab-
iting hot springs can provide insights into the origin and
early evolution of life, as they are considered the direct
descendants of the earliest living forms on Earth (Weiss
et al. ).
1472 © IWA Publishing 2018 Water Science & Technology: Water Supply | 18.4 | 2018
doi: 10.2166/ws.2017.215
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