Title Diversity of Cyanobacterial Species and Phylotypes in Biofilms from the Littoral Zone of Lake Baikal
Author Ekaterina G. Sorokovikova*, Olga I. Belykh, Anna S. Gladkikh, Oleg V. Kotsar, Irina V. Tikhonova, Oleg A. Timoshkin, and Valentina V. Parfenova
Address Limnological Institute, Siberian Branch of Russian Academy of Sciences, 3, Ulan-Batorskaya, 664033 Irkutsk, Russia
Bibliography Journal of Microbiology, 51(6),757–765, 2013,
DOI 10.1007/s12275-013-3240-4
Key Words cyanobacteria, biofilm, epilithon, Lake Baikal, Rivularia, pyrosequencing
Abstract The majority of naturally occurring biofilms contain numerous microorganisms that have not yet been cultured. Additionally, there is little information available regarding the genetic structure and species diversity of these communities. Therefore, we characterised the species diversity, structure and metagenome of biofilms grown on stones and steel plates in the littoral zone of Lake Baikal (East Siberia, Russia) by applying three different approaches. First, light microscopy enabled identification of the species diversity of biofilm-forming cyanobacteria on different substrates with the dominance of Rivularia rufescens, Tolypothrix limbata, Chamaesiphon fuscus, Сh. subglobosus, and Heteroleibleinia pusilla. Additionally, scanning electron microscopy was used to show the spatial structure of biofilms. Finally, sequence analysis of 30,660 16S rRNA clones indicated a high diversity within the biofilm communities, with the majority of the microbes being closely related to Cyanobacteria (8–46% sequences), Proteobacteria (14–43%), and Bacteroidetes (10– 41%). Rivularia sp., Pseudanabaena sp., and Chamaesiphon spp. were the dominant cyanobacterial phylotypes.