Morphological characterization and phylogenetic analysis of aeroterrestrial Vischeria/Eustigmatos strains with industrial potential

Abstract

Microalgae are subject of extensive scientific and commercial interest in terms of both fundamental ecology and biotechnological potential. Here, we describe five Bulgarian aeroterrestrial strains of the Eustigmatos/Vischeria group, which have shown potential as valuable carotenoid producers. The strains are stored in the algal collection of Sofia University (ACUS). The main cytological and morphological diagnostic features of the studied eustigmatophycean stramenopile algae remained stable during long-term cultivation, showing that immediate light microscopy (LM) identification in cultures is reliable. We used a polyphasic approach for taxonomical identification, combining conventional microscopy of culture material with molecular-genetic methods (based on rbcL gene sequencing). This approach led to almost similar taxonomic results, supporting the need for unification of the genera Eustigmatos and Vischeria (which are presently separated on the basis of morphological features). Based on the obtained results, we speculate that there could be new eustigmatophyceaen aeroterrestrial taxa. This, however, needs to be confirmed in more refined molecular-genetic studies with a view to exploiting the full biotechnological potential of the aeroterrestrial Eustigmatos/Vischeria strains described here. ARTICLE HISTORY

Carotenoids in five aeroterrestrial strains fromVischeria/Eustigmatosgroup: updating the pigment pattern of Eustigmatophyceae

“…They were initially identified by means of light microscopy [29,30,32]. Molecular-genetic methods confirmed their group and genetic affiliation [33] with Vischeria stellata (Chodat ex Poulton) Pascher included as Endangered species in the Red List of threatened microalgae in Bulgaria [34].…”

Review on the biotechnological and nanotechnological potential of the streptophyte genusKlebsormidiumwith pilot data on its phycoprospecting and polyphasic identification in Bulgaria

“…This was done in the cultivation room of the AgroBioInstitute (ABI) of the Agricultural Academy of Bulgaria. The temperature was 22-23 C and a 16/8 light/dark photoperiod was maintained with cool white fluorescent lamps [1,3].…”

“…The interest in phycoprospecting, or searching for local algal strains of commercial interest, is rapidly increasing parallel to the need for reliable identification of discovered algae, based on the polyphasic approach [1]. Algae have become a central focus of bioeconomy and biotechnology in particular due to their countless applications starting from food and pharmaceuticals to biofuels [2][3][4].…”

Study of the Polysaccharide Production by the Microalga Vischeria punctata in Relation to Cultivation Conditions

“…The genus Vischeria was recently shown to be identical to the genus Eustigmatos and these genera are now merged. Eustigmatos is mentioned in papers [ 6 , 7 , 8 ]; however, the exopolysaccharides of the microalgae V. punctate have received little attention [ 6 ]. Soils, subaerial space (for example, tree bark), and fresh waters are the habitats of the members of the genus Vischeria .…”

“…Vischeria punctata is a unicellular microalga that has industrial potential, as it can produce substances with beneficial properties [ 7 ]. In recent years, Eustigmatophyceae , which include V. punctate , have attracted increasing attention because they are biotechnologically promising in terms of biomass growth, production of lipids, pigments, and other compounds [ 9 ].…”