Pioneer species of Cyanobacteria in hot springs and their role to travertine formation: The case of Aedipsos hot springs, Euboea (Evia), Greece

Abstract

Cyanobacteria are considered to be among the first microorganisms to settle in hot springs where they form a favourable environment for further biological establishment. Nevertheless, the exact pioneer species and how early they start participating in the biomineralisation processes remain unknown. The aim of the present study was twofold, that is, to identify the pioneer Cyanobacteria in hot springs (i.e. Aedipsos area, Greece) and to record their early biomineralisation processes. The in situ experimental approach included the setup of sterile glass and/or plexiglass slides in several locations to facilitate colonisation by Cyanobacteria, and removal of slides for study after 48-202 h. Synechococcales (37%) and Oscillatoriales (33%) were the dominant orders, followed by Chroococcales (15%) and Spirulinales (11%); whereas Chroococcidiopsidales (4%) was found only in a few sites. The order Nostocales was not observed at the early stages of colonisation although it was present in mature stages. Fortythree species of Cyanobacteria were identified as pioneer microorganisms, with Spirulina subtilissima being the most frequently found. The most common pioneers were multicellular filamentous Cyanobacteria, that is, organisms with a large surface area able to form significant amounts of extracellular polymeric substances. Among the pioneers, thermophilic species of Cyanobacteria were typical such as Chroococcidiopsis thermalis, Chroococcus thermalis, Leptolyngbya thermalis, S. subtilissima and Symploca thermalis, as well as typical limestone substrate species such as Chroococcus lithophilus and Leptolyngbya laminosa. Temperature seems to affect biodiversity. Also, pioneers were found to contribute to the biomineralisation processes from their first appearance. In the studied samples, three biomineralisation processes were identified, that is, (i) calcification of cyanobacterial sheaths, (ii) trapping of carbonate crystals on a crystal retention lattice formed by extracellular polymeric substances and filaments and (iii) trapping and confinement of carbonate crystals around filamentous Cyanobacteria.

Taxonomic and Ecological Aspects of Thermophilic Cyanobacteria from Some Geothermal Springs of Jharkhand and Bihar, India

“…schmidlei, and Mastigocladus laminosus had an affinity with high NO 3 -, K + , Na + and SO 4 2and with low pH, T, CI -, and PO 4 3in this study (sampling sites S1A). Similar to this study, Spirulina subtilissima was not related to temperature in Öztürk ( 2021), but contrary to these studies, the taxon was detected at higher temperatures in the study by Kanellopoulos et al (2022). Mastigocladus laminosus, which did not show a positive correlation with temperature and pH in this study, on the contrary, has a positive correlation with the temperature and pH in the study by Singh et al (2018) Arman et al (2014), it was reported that it was determined from 53 °C, 6.86 pH, and 1945mg/L SO 4 2water parameters.…”

Antimicrobial Properties of Capsaicin: Available Data and Future Research Perspectives

“…Apart from finding natural alternatives to antibiotics, this is important both for those patients in which some antibiotics may be toxic-typical examples include allergies [63][64][65], liver toxicity [66][67][68][69], and other side effects [70]-and also, and perhaps more significantly, due to the increasing antibiotic resistance [71][72][73][74][75][76][77]. The rapid increase in antibiotic resistance is mainly explained by the overuse of antibiotics [78][79][80] and the high adaptability of bacteria in general, which may survive, depending on the species, even in extreme environments such as hot springs (e.g., [81][82][83]). The research on the antibacterial properties of capsaicin is extensive (Table 1) and this leaves open many potential choices for new drug design.…”

Microbial Mat Stratification in Travertine Depositions of Greek Hot Springs and Biomineralization Processes

“…The travertines present a large variety of facies [28,30,31,49] with strong indications of biomineralization processes [28,29]. Recent studies prove the contribution of Cyanobacteria to the formation of travertines [32], even in the very early stages of Cyanobacteria settlement [33].…”

“…Previous studies have been conducted in the study of the thermogenic travertine of Northern Euboea (Greece) [28][29][30][31][32][33][34]. The present study is the first attempt to examine the stratification of microbial mats in the hot springs of the Aedipsos area (i.e., biodiversity, mineralogical composition, and biomineralization processes of calcium carbonate minerals taking place at the top layers).…”