First Evaluation of Associated Gut Microbiota in Wild Thick-Lipped Grey Mullets (Chelon labrosus, Risso 1827)

Abstract

This study aimed to characterize the intestinal microbiota of wild thick-lipped grey mullets (Chelon labrosus) and explore its potential functionality on the host. Intestinal contents of anterior and posterior sections from wild fish were collected and DNA was extracted. Subsequently, the V3–V4 regions of 16S rRNA were sequenced using the Illumina technology and results were analyzed by bioinformatics pipeline. The functional profile of the microbial community was analyzed using PICRUSt software. Shannon and Simpson diversity indices were significantly higher in the posterior section of wild specimens. The overall taxonomic composition suggests a certain homogeneity in the anterior section of the intestine and heterogeneity in the posterior section. Due to this, no statistical differences were detected at any level among both intestinal sections. Predicted functions of intestinal microbiota showed the most abundant were those related to amino acid metabolism, carbohydrate metabolism, energy metabolism, membrane transport, and cell replication and repair. Furthermore, the analysis revealed microbial functional genes related to the elimination of environmental toxins.

Microbial Communities Associated with the Intestinal Tract of Grey Mullets from a Mediterranean Aquatic Environment

“…culture of grey mullets Mugilidae species is considered a priority within the current strategies of sustainable European aquaculture [21]. To the authors' knowledge, various studies were made on the gut microbiota of cultured [41] and wild mullets [23,31] and the present study has provided more information on the biodiversity of this ecosystem and their biotechnological potential. Previous studies on Mediterranean grey mullets had showed some interesting biotechnologically traits of intestinal cultivable bacteria as a source of bioactive compounds with immunological and bioremediation functions [42].…”

“…In particular, members of Chloroflexi phylum belonging to the Anaerolineaceae family, found at an abundance of more than 6% in the mullets collected in autumn, are described in literature as methano-genic bacteria (hydrocarbon degrading), frequently encountered in presence of petroleum. The presence of bacteria able of degrading toxic substances as aromatic compounds (sty-rene and fluorobenzoate) on Chelon labrosus was also pointed out by means of PICRUSt functional analysis [23], although their role is still unclear and most of this group of microorganisms remains uncultured and understudied [49].…”

“…In this sense, grey mullets represent an interesting resource for aquacultural use since, the poten-tial for fish large scale production faces numerous challenges represented by ecological carrying capacity of existing sites and environmental impact [22]. Moreover, the valoriza-tion of fish species less considered for the market is a way for preserving the more valued ones and the biodiversity of the aquatic environment [23].…”

“…Earlier studies reported the composition and the predicted functions of the associated gut microbiota on Mugil cephalus of different ages from Northwest Pacific marine envi-ronments [30], from Chinese coastal marine areas [31] and on Mediterranean wild thick-lipped grey mullets (Chelon labrosus, Risso 1827) [23]. However, the intestinal microbiota of wild grey mullets from Mediterranean aquatic environments still deserve more explora-tions and remains an important topics of scientific interest.…”

Microbiome analysis reveals potential for modulation of gut microbiota through polysaccharide-based prebiotic feeding in Oreochromis niloticus (Linnaeus, 1758)

“…Microbial metabolic pathway analysis using PICRUSt is mostly suggested in association with carbohydrates, protein, amino acids, energy metabolism, membrane transport, nutrient digestion, immune function, and xenobiotic metabolism within the fish gut ( García-Márquez et al, 2022 ). Feeding habits and trophic levels of fish are important factors to determine parts of the gut microbe community.…”