Extremophilic cyanobacteria from thermo-mineral springs of spas in Atlantic environments

Abstract

The species composition of cyanobacteria assemblages was studied in six thermo-mineral springs of spas in Atlantic environments of Galicia (NW Spain). Two are considered hot (T^a ≥ 40 °C), two intermediate (T^a 20–40 °C) and two cold (T^a ≤ 20 °C), and four contain hydrogen sulphide. A total of 21 taxa (14 genera) have been recorded. Two diversity indices, Shannon index and Evenness were determined. The Shannon–Wiener index ranged between 0.31 and 0.73 and the Evenness index between 0.44 and 0.88. nMDS ordination showed that cyanobacteria assemblage composition was influenced mostly by temperature. Of the species identified, the most diverse genus is Leptolyngbya with four species, followed by Chroococcus with three species and Aphanocapsa, Phormidium and Lyngbya with two species. The most abundant species was Jaaginema angustissimum, followed by Leptolyngbya laminosa and Symploca thermalis. In the two cold springs, seven different species were found, and only Aphanocapsa conferta was common to both springs. Cyanobacterial species were more numerous in the four hot springs, with 15 different species and only Calothrix thermalis common to these hot springs. It is difficult to establish characteristic cyanobacterial flora for the thermo-mineral waters of the Galician springs since there are significant differences in the communities from the six sites studied.

Key words:

• Atlantic environments
• cyanobacteria
• diversity
• environmental parameters
• Galicia (NW Spain)
• spa
• thermo-mineral springs
• thermal-sulphur waters

Acknowledgements

The authors are grateful to Matt Smith for language correction

Authors contributions

M.C.L., A.D.A. and R.M. conceived and designed the sampling. M.C.L., A.D.A. and E.T. analysed the data. M.C.L., A.D.A. and E.T. wrote the paper and contributed to the general discussion, revision and manuscript editing. All authors read and approved the final manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Associate Editor: Professor Elliot Shubert

Additional information

Funding

This work was supported by Programa de Promoción Xeral da investigación do Plan Galego de IDIT (10 PXIB 310 153 PR) of Consellería de Innovación, Industria y Comercio of Xunta de Galicia. This Project has received financial support provided by the recognition as a Research Competitive Reference Group (GRC GI-1809 BIOAPLIC, ED431C 2019/07), and the Research Strategic Grouping BioReDes (ED431E 2018/09) by Consellería de Educación, Universidade e Formación Profesional of Xunta de Galicia.