Distribution survey of Cyanobacteria in three Greek caves of Peloponnese

Caves and hypogean environments host various phototrophic microorganisms, with Cyanobacteria constituting the major group. The spatial and temporal distribution of Cyanobacteria (156 taxa in total) from three Greek caves, located in the limestone arc of Peloponnese and differing in morphology, was studied. The community patterns in different ecological niches were analyzed in relation to environmental parameters (Photosynthetically Active Radiation, Temperature, and Relative Humidity). Cyanobacterial communities were found to thrive in patchy biofilms and showed known protective strategies against desiccation and irradiation. The nMDS analysis of the cumulative seasonal samples per sampling site showed no general pattern of distribution, with a clear differentiation of cyanobacterial communities among the three caves. Only in the typical cave ‘Kastria’, cyanobacterial taxa showed growth habits in accordance with the gradient of light from entrance inwards

Thermogenic travertine deposits in Thermopylae hot springs (Greece) in association with cyanobacterial microflora

The present paper deals with the investigation of abiotic and biotic influence on thermogenic travertine formation in Thermopylae hot springs, one of the largest active thermogenic travertine systems in Greece. Geological, mineralogical and microbiological data from three different types of travertines (cascades, terraces and fluvial crusts) revealed different cyanobacterial communities. Microscopic analysis of fresh and cultured material has shown that epilithic and endolithic cyanobacteria are almost the exclusive components of travertines’ photosynthetic microflora. Thirty-one (31) taxa of cyanobacteria are presented here, among them the frequently found, in such environments, Phormidium incrustatum and Aphanocapsa thermalis, as well as the taxonomically interesting diazotrophic morphotype identified as Chlorogloeopsis sp. Sampling sites I and II have similar formation conditions characterized by laminated travertines with low porosity and shrub lithotypes, with the cyanobacterium Leptolyngbya ercegovicii occupying an endolithic zone, while the upper part is occupied by colonial chroococcalean species. On the contrary, sampling site III is characterized by laminated travertine with fenestrial type porosity and absence of shrub lithotypes resulting in a completely different community of cyanobacteria. © 2015, Springer-Verlag Berlin Heidelberg

Phenotypic and Molecular Biological Characterization of Cyanobacteria from Marble Surfaces of Treated and Untreated Sites of Propylaea (Acropolis, Athens)

Cyanobacteria cause aesthetic damage to marble surfaces and in particular their endolithic mode of life contributes to the breakdown of rock crystalline structures. The aim of this work was to estimate, with both phenotypical and molecular approach, the composition of cyanobacterial communities on the Propylaea marbles of the Acropolis Monuments. The two selected sampling sites were treated and untreated with a commercial biocide in order to estimate its effect on the cyanobacterial diversity. Our study revealed that in both sampling sites were present 13 phenotypes and 10 phylotypes and that the cyanobacterial taxa were considerably lower in the treated site. © 2013 Copyright Taylor and Francis Group, LLC

Distribution survey of Cyanobacteria in three Greek caves of Peloponnese

Caves and hypogean environments host various phototrophic microorganisms, with Cyanobacteria constituting the major group. The spatial and temporal distribution of Cyanobacteria (156 taxa in total) from three Greek caves, located in the limestone arc of Peloponnese and differing in morphology, was studied. The community patterns in different ecological niches were analyzed in relation to environmental parameters (Photosynthetically Active Radiation, Temperature, and Relative Humidity). Cyanobacterial communities were found to thrive in patchy biofilms and showed known protective strategies against desiccation and irradiation. The nMDS analysis of the cumulative seasonal samples per sampling site showed no general pattern of distribution, with a clear differentiation of cyanobacterial communities among the three caves. Only in the typical cave 'Kastria', cyanobacterial taxa showed growth habits in accordance with the gradient of light from entrance inwards

Cyanobacteria and associated invertebrates in Leontari Cave, Attica Greece

The present paper deals with biocommunities of cave Leontari, Attica (Greece) focusing on its lithophytic cyanobacteria, and the associated microfauna. The cave is of archaeological importance, not touristically exploited, naturally lighted through the entrance; it consists of one chamber with poor stalactite and stalagmite limestone decoration. During a survey in three campaigns, samples of cyanobacteria and soil invertebrates were collected from four sites (1-1V) along a light(PAR)-temperature-humidity gradient. Light microscopic observations of natural and cultured material have shown that epilithic and endolithic cyanobacteria were almost the exclusive component of cave photosynthetic microflora. Twenty two taxa were identified including the taxonomically interesting morphotypes Chroococcus spelaeus, Asterocapsa sp. and Chlorogloea sp. Arthropods were found as dominant soil invertebrates represented by nine taxa. © Czech Phycological Society

Spelaeonaias gen. Nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)

Based on aspects of the classical LM morphology, and a combination of ultrastructural and molecular data, a new truebranched cyanobacterium, i.e. Spelaeonaias floccida Lamprinou, Christodoulou, Hernández-Mariné et Economou-Amilli, gen. Nov. Sp. Nov., is described from the Greek cave Vlychada (part of the ‘Diros’ cave complex, Peloponnese, Greece). The new monospecific genus bears a Y-like type of branching, intercalary heterocytes and terminal heterocytes at the ensheathed hormogonia, thus morphologically resembling Symphyonemopsis. The subaerophytic growth of the ensheathed hormogonia is considered as the autapomorphic feature for Spelaeonaias. The 16S rRNA sequencing revealed that S. Floccida forms a well congruent monophyletic cluster along with two stigonematalean strains SA1301 and SP302 from Maltese catacombs (GenBank: HQ917695 and HQ917696 respectively). © 2016 Magnolia Press

A new species of Phormidium (Cyanobacteria, Oscillatoriales) from three Greek Caves: Morphological and molecular analysis

Specimens of cyanobacteria were collected from three geographically distant caves in Greece, and an interesting species of the Oscillatoriales was isolated and analyzed. Morphological characters were analyzed from fresh and cultured material using LM, SEM and TEM; moreover, molecular analysis based on the 16 S rRNA sequence was applied. This cyanobacterium bears a characteristic blackish, stratified, mucilaginous sheath and it is characterized by entangled flaments, facultative presence of false branching, presence of necridia and peripheral arrangement of thylakoids. The autapomorpic blackish mucilaginous sheath and the pseudobranching flaments are unique morphological characters within the genus Phormidium, according to classical taxonomy. The 16 S rRNA sequence showed relatedness to Phormidium priestleyi ANT L52.6 with 97-98 % similarity, but without morphological support. Both phenotypic and genetic traits supported the designation of a new species, under the name Phormidium melanochroun Lamprinou & Pantazidou sp. nov. © 2013 E. Schweizerbart'sche Verlagsbuchhandlung

Insights on the biomineralisation processes and related diversity of cyanobacterial microflora in thermogenic travertine deposits in Greek hot springs (North-West Euboea Island)

The aim of this study is to identify the biomineralisation processes in hot springs of North-West Euboea Island by assessing the physico-chemical parameters of the hot water, the travertine mineralogical composition and facies, and the cyanobacterial microflora. In the studied area, the main mineral phases are calcite and aragonite, creating laminated and shrub facies of travertine deposits in close association with the cyanobacterial microflora. Microscopic analysis of fresh and cultured field samples shows the presence of 81 taxa of Cyanobacteria belonging to six orders, that is, Oscillatoriales, Synechococcales, Spirulinales, Chroococcales, Nostocales and Chroococcidiopsidales with the main factors controlling biodiversity being temperature, salinity and access to sunlight. No Cyanobacteria species were identified in areas with temperatures over 65oC. In areas with high salinity (27–37‰), the order Oscillatoriales predominates. On the other hand, in areas with high temperatures (63oC), fewer orders were observed, usually only Synechococcales and Spirulinales. In areas with lower temperatures (37oC), larger numbers of Cyanobacteria orders were identified. Additionally, salinity seems to regulate the presence of the Nostocales order. The combined geobiological study revealed the presence of four biomineralisation processes involving calcium carbonate minerals, that is, (i) filamentous Cyanobacteria and extracellular polymeric substances trapping calcium carbonate crystals, (ii) extracellular polymeric substances acting as a template favouring mineral precipitation for crystal nucleation, (iii) formation of calcified Cyanobacteria sheaths and (iv) alteration of calcium carbonate crystals by endolithic Cyanobacteria. The identified biomineralisation processes suggest that the formation of calcium carbonate crystals is due to the metabolic activity of Cyanobacteria, or that the Cyanobacteria favour the deposition or the alteration of already existing crystals. The combination of these processes and the non-biotic (abiotic) mineralisation result in the formation of hybrid carbonates in the study area. © 2022 The Authors. The Depositional Record published by John Wiley & Sons Ltd on behalf of International Association of Sedimentologists

Morphology and molecular evaluation of iphinoe spelaeobios gen. nov., sp. nov. and Loriellopsis cavernicola gen. nov., sp. nov., two stigonematalean cyanobacteria from Greek and Spanish caves

Caves have generally been found to host phototrophic micro-organisms from various taxonomic groups, with cyanobacteria comprising an important group that have adapted to these stable and highly specific environments. A polyphasic study based on aspects of classical morphology and molecular data revealed two new monospecific genera from fresh material of Greek and Spanish caves. Both taxa are characterized by obligatory true branching (T-type, V-type and false branching), the presence of heterocysts, and reproduction by hormocysts and akinetes. They shared some similarities in their morphological characteristics as revealed by light, scanning electron and transmission electron microscopy, but phylogenetic analysis based on 16S rRNA gene sequences showed that the two phylotypes were different (89.8% similarity); this represents an example of shared morphology in genetically different strains of cave-adapted species. Phenotypic and genetic traits strongly support classification of the phylotypes as independent taxa in the order Stigonematales (the most differentiated and complicated group of cyanobacteria), family Loriellaceae Geitl 1925. Hence, the names Iphinoe spelaeobios Lamprinou and Pantazidou gen. nov., sp. nov. and Loriellopsis cavernicola Herna ́ndez-Marine ́and Canals gen. nov., sp. nov. are proposed. © 2011 IUMS