Gut microbiome of the White Sea fish revealed by 16S rRNA metabarcoding

Abstract

To date, it has been increasingly clear, that microbiota plays essential role in the host microorganism. Due to high phylogenetic diversity and wide distribution understanding of gut microbiota of fish is ambiguous. We elucidate previously undescribed diversity of bacteria in the White Sea fish posterior intestine based on 16S rRNA metabarcoding: shorthorn sculpin (Myoxocephalus scorpius), lumpfish (Cyclopterus lumpus) arctic flounder (Liopsetta glacialis), cod (Gadus morhua), and herring (Clupea pallasii). Proteobacteria were most abundant in all the samples. All datasets contained high number of reads corresponded to Psychrobacter, Halomonas, Pseudoalteromonas and Vibrio abundant in the White Sea water.Vast majority of bacterial reads corresponded to the Vibrionaceae (Aliivibrio, Vibrio, and Photobacterium). It is in accordance with our previous study focused on bioluminescent bacteria, where we isolated strains of these genera from the same fish intestine samples. The datasets of G. morhua and Cl. pallasii were enriched by reads of Shewanella (also isolated previously microbiologically due to luminescence of some its strains); the datasets of G. morhua and M. scorpius contained high number of Mycoplasma, which is in line with previous reports on the microbiome of marine fish gut from other geographical regions. Collectively, on the one hand, the study is a confirmation of known data on marine fish gut microbiome, on the other hand, it reveals some specific patterns of White Sea fish gut microbiota, e.g. presence of bacteria common for water from this region.