Algal cultures as a model object of studding algal-bacterial communities (consortia)

Abstract

An information on the results of the microbiological analysis of xenic cultures of green (<i>Chlorophyta</i>) and charophytes (<i>Charophyta</i>) algae is given. Algal xenic cultures are regarded as communities (consortia) of heterogeneous organisms connected with each other by trophic and topic interactions and composed of a center nucleus (autotrophic algae of one species) and consorts (several species of heterotrophic bacteria). Twelve algal xenic cultures of freshwater (<i>Сhlorella vulgaris</i> Beij., <i>Coelastrum</i> <i>rugosum</i> (P.G. Richt.,<i> Tetradesmus dimorphus</i> (Turpin) M.J.Wynne) and aerophitic (<i>Klebsormidium flaccidum</i> (Kütz.) Silva, Mattox et Blackwell) algae from the collection of M.G. Kholodny Institute of Botany NAS of Ukraine were used in investigations. Each species was represented by three strains isolated in 1961–2018 years from the territories of Ukraine and other countries of Eurasia. Overall, 82 bacterial strains were isolated and identified according to some phenotypic (morphological, chemotaxonomic, physiological and chemical) features. The study revealed complexes of four types which consisted 7 species of bacterial consorts. A qualitative composition of complexes was the same in cultures (strains) of one certain algal species but strictly different in cultures of another algal species. Although, some bacterial species were found in several complexes of different type. It is evident a tight association the heterotrophic bacterial consorts with the autotrophic determinant of consortia and conforms the consortium character of algal-bacterial communities in general. It was proposed an express method based on the use of a numerical system for morphological evaluation of bacterial colonies in preliminary study peculiarities, features and functions of consortia.