Comparative characteristics of metabolites from various cyanobacteria biofilms

Abstract

Cyanobacterial communities collected from the Ruskeala marble in the territory of Ruskeala quarry and granite-rapakivi from quarries of Southern Finland are compared. Two types of cyanobacterial biofilms were characterized by external features, diversity, and composition of metabolites. Identification of cyanobacteria was carried out according to morphological characters. In total, forty-nine cyanobacteria taxa belonging to four orders, fifteen families, twenty-two genera were revealed. Of these, forty-one taxa were identified on granite outcrops, and eighteen taxa on marble substrate. A complete list of cyanobacterial species in decreasing order of occurrence is presented in the text. Calothrix parietina is defined as the dominant of the first type biofilm on marble, Gloeocapsa atrata on granite. For the second type of biofilms, a greater abundance of Gloecapsopsis magma was noted, and a variety of cyanobacteria from the genus Gloeocapsa (6 taxa) on both types of substrate. Metabolomic analysis revealed that the first type of biofilm contains mono-, di- and trisaccharides and amino acids in high concentrations, and the second type is characterized by a clear dominance of sugar alcohols. In general, biofilms of the second type on marble and granite are more similar in composition to metabolites than biofilms of the first type. The role of cyanobacterial biofilms in the biodegradation of stony substrates is discussed. It was noted that in biofilms of the first type there is less malic and oxalic acid on marble than on granite, which is most likely due to the binding of these metabolites to calcium, which is part of the substrate.