Comparison of bacterial diversity and species composition in three endemic Baikalian sponges

Abstract

Baikalian sponges are unique organisms with many species harboring symbiotic microbes that produce novel bioactive compounds. To investigate bacterial diversity of three species of Baikalian sponges, specimens of Lubomirskia baicalensis, Baikalospongia intermedia and Swartschewskia papyracea collected from Lake Baikal were processed by pyrosequencing. We found differences in the species composition and diversity in bacteria among these sponges. Cyanobacteria accounted for the highest proportion and the second group was Proteobacteria in three sponges. The bacterial communities in B. intermedia and L. baicalensis were highly similar but less similar to the bacterial community associated with S. papyracea. Diversity of the bacterial community in S. papyracea was higher than in L. baicalensis and B. intermedia. In particular, the relative abundance of Actinobacteria was higher in S. papyracea. Bacterial species in phyla Acidobacteria and Gemmatimonadetes were only found in S. papyracea.

Brown Rot Syndrome and Changes in the Bacterial Сommunity of the Baikal Sponge Lubomirskia baicalensis

“…The analysis of 16S rRNA gene of the bacterial community associated with sponges highlighted a more diverse microbial community in healthy L. baicalensis than in previously studied specimens [13,14]. This might be explained by differences in sample preparation and amplification strategy.…”

“…In high microbial abundance (HMA) species, microorganisms can represent up to 40% of the sponge biomass [6] and show great taxonomic diversity, with up to 47 bacterial or candidate phyla recorded so far [7][8][9]. Acidobacteria, Actinobacteria, Bacteroidetes, Chloroflexi, Cyanobacteria, Proteobacteria (Alphaproteobacteria, Betaproteobacteria, Gammaproteobacteria, Deltaproteobacteria), Verrucomicrobia, and Nitrospira phyla are the most common both in marine [4,10] and freshwater sponges [11][12][13][14]. Sponge disease outbreaks or mass mortality events have been reported for more than a century, with more than 20 events studied, sometimes affecting several species and large areas [4,[15][16][17][18][19][20][21][22][23][24][25][26][27][28].…”

Phylogeny of the freshwater lineages within the phyla Actinobacteria (Overview)

“…Molecular approach enabled identifying in the water column the species Planktophila limnetica (acI) typical of bacterioplankton (Parfenova et al, 2013;Gladkikh et al, 2014), the orders Actinomycetales and Acidimicrobiales as well as other unclassified Actinobacteria (Mikhailov et al, 2015;. The genus Planktophila and the order Acidimicrobiales were found in all species of healthy Baikal sponges (Seo et al, 2016), and the representatives of the genera Ilumatobacter and Iamia (acIV) were identified in diseased sponges L. baicalensis and Baicalospongia intermedia (Krasnopeev et al, 2016). In the sub-ice waters, there were Actinobacteria of the genus Ilumatobacter (acIV) (Bashenkhaeva et al, 2015), freshwater acI ones, the acAcidi group, the family Acidimicrobiaceae and other unclassified Actinobacteria (Bashenkhaeva et al, 2017;Cabello-Yeves et al, 2018).…”

Microbiological studies of Lake Baikal in a Limnological institute: past and present

“…These works set a new stage for investigations of microorganisms in the lake and became a real breakthrough in the understanding of the composition of bacteria in the water column, fouling and bottom sediments (Belikov et al, 1996;Belkova et al, 1996;Denisova et al, 1999). The period from 2000 to the present has been a productive time for identifying the genetic diversity of the autotrophic picoplankton communities (Semenova, 2001;Tikhonova, 2006;Belykh et al, 1999;2011), bacteria of the water column (Belkov, 2004), sponges (Kalyuzhnaya, 2012), the intestinal microflora and external integuments of fish (Sukhanova, 2012) and benthic cyanobacteria (Gladkikh, 2012). Genetic biodiversity and a complex characterization of microbial communities from bottom sediments, occurrence areas of gas hydrates, seepages of oil and hydrocarbon gas, bitumen structures and barrier inflow zones of the main Baikal tributaries were observed in a series of works headed by T.I.…”

“…In 2010, metagenomic analysis of communities was used for the first time to determine the diversity of microbiocenoses, when this research area had only begun to develop in Russia. The first results showed the high diversity and large metabolic potential of bacteria from biofilms of bottom substrates (Perfenova et al, 2008;Malnik, 2010;Gladkikh, 2012;Sorokovikova et al, 2013), sponges (Gladkikh et al, 2014;Jung et al, 2014;Seo et al, 2016) and the surface microlayer (Galachyants et al, 2016;Galach'yants et al, 2016;2017). At the present time, an analysis of the genetic diversity of microbial communities of various habitats of Lake Baikal was performed using high-throughput sequencing (Fig.…”