Supervisors info:
Πανταζίδου Α. Αναπλ. Καθηγήτρια ΕΚΠΑ (επιβλέπουσα), Οικονόμου-Αμίλλη Α. Καθηγήτρια ΕΚΠΑ, Παρμακέλης Α. Επίκ. Καθηγητής ΕΚΠΑ
Summary:
Prokaryotic cyanobacteria and eukaryotic diatoms represent photosynthetic
organisms with a worldwide distribution, which can been found also in thermal
springs. The aim of the present contribution is to study, for the first time,
the diversity of these microorganisms in relation to the main abiotic
parameters in the main outflows of the mesothermic (37οC) spring ‘Pozar’, an
area of touristic exploitation located in Loutraki of Aridaia (Pella’s
District). Sampling was conducted in November 2011 and April 2012, from four
‘natural’ (non affected by the balneotherapy activities) sites. Recording of
coordinates (GPS) was made at each sampling site, together with measurements of
the main physical and chemical water parameters (temperature, conductivity,
salinity and pH). The mat selection was based on the presence of distinct,
variously colored, outgrowths of algae. Material was partly fixed in
formaldehyde solution 2.5% and partly kept alive for culturing in laboratory
conditions using the suitable culture liquid medium (BG11). In the laboratory,
the morphological characters of Cyanobacteria and Diatoms were studied under
the light microscope (LM). After microscopic observation of both natural and
cultured material, more than 15 chroococcalean and oscillatorialean morphotypes
of cyanobacteria were classified based on the taxonomic system of Komarek &
Anagnostidis (1998, 2005). Among the accompanying dominant diatoms, observed
after the classic acid treatment of cultured material, were the genera
Nitzschia Hassall, Navicula Bory de Saint-Vincent and Pinnularia Ehrenberg.
With the method of serial dilutions one filamentous cyanobacterian species
belonging to the family Phormidiaceae was isolated, temporarily classified as
Sympoca cf. thermalis (Gomont ex Gomont, 1892) Anagnostidis & Komarek 1986. The
quantitative determination of total lipids and analysis of the composition in
fatty acids, made with gas chromatography on Symploca thermalis, showed the
presence of a polyunsaturated acid of great interest, i.e. the 18:3 linoleic
acid found in our samples in a significanly great amount (41%). The taxonomical
classification of the above interesting Symploca morphotype was carried out
with molecular techniques and the phylogenetic analysis based on the 16S rDNA
gene. Detailed morphological descriptions of this cyanobacterium are also given
by scanning electron microscopy (SEM).
Keywords:
Cyanobacteria, Hot springs, Microalgae, Diatoms, Pozar Aridaia
