First characterization of the gut microbiome associated with Mytilus chilensis collected at a mussel farm and from a natural environment in Chile

Abstract

The gut microbiome of Mytilus chilensis was analyzed using a next-generation sequencing (NGS) approach using as target the V6-V8 16S rDNA gene regions. The resident gut bacterial communities were analyzed in individuals collected from two locations, both free-living in natural conditions (Wild Type group, WT) and those found in intensive commercial cultures at a Mussel Farm (MF group) off the Chilean coast. A total of 1.2 M of non-chimeric sequences were detected, belonging to 30 phyla, including Fusobacteria, Proteobacteria, Bacteroides, Tenericutes, and 404 genera taxa. The major fraction of the sequences detected corresponded to Vibrionaceae and Fusobacteriaceae families for MF and WT groups, respectively. The gut microbiome of M. chilensis showed a wide diversity of microorganisms; however, differences were observed depending on the origin of samples, where gut samples from the mussel farm showed a lower number of genera when compared to gut tissue samples collected from the wild type individuals. The dominant bacterial are Vibrio, Psychrilyobacter, Mycoplasma, and Psychromonas, that were present with different relative abundancies among the samples analyzed. This next generation sequencing technique, applied for the first time in Chilean mussel (M. chilensis), showed that the gut is a useful tissue for the study of bacterial communities in this bivalve mollusk. The results obtained in this work provided insights into the composition of the microbiota of M. chilensis, unravelling the great bacterial diversity and the effect of habitat on the bacterial community structure.