Environmental contamination alters the intestinal microbial community of the livebearer killifish Phalloceros caudimaculatus

Abstract

Intestinal microbiota perform important functions for the health of fishes. Knowing the microbial composition and evaluating the possible effects caused by anthropogenic pollution in the intestinal microbiota of fish populations might represent an important step in defining microbial biomarkers for water pollution. This study evaluated the impact of environmental contamination on the gut microbiota of the livebearer killifish Phalloceros caudimaculatus. The 16S survey using the V4 region of the 16S rRNA gene was used to characterize and compare the microbiota of two P. caudimaculatus populations from streams with different levels of environmental contamination in Rio Grande, RS, Brazil. Twelve bacterial operational taxonomic units (OTUs) (around one-third of the total) were shared between both fish populations. They represent the core microbiota of the gut in this species. The dominant phyla were Protebacteria and Firmicutes, with more than 80% of relative abundance. The dominant genus was Burkholderia with more than 35% of the relative abundance irrespective of the environmental condition. We detected a lower microbial diversity (Shannon index and observed OTUs) in fish from the polluted stream compared to the reference stream. The PERMANOVA analysis showed that the intestinal microbial communities from fish living in the polluted stream were distinct from those found in the reference stream (p < 0.05). Finally, we identified Luteolibacter, Methylocaldum and Rhodobacter genera, which correlated strongly with the polluted stream. These taxa might represent potential microbial biomarkers of exposure to environmental contaminants in the guts of fish. Confirmation of these findings in other polluted environments might allow the development of a microbiota-based screening approach for environmental evaluation in ecotoxicological studies in aquatic ecosystems.

Diversity, Composition, Taxa Biomarkers, and Functional Genes of Fish Gut Microbes in Peat Swamp Forests and its Converted Areas in North Selangor, Malaysia

“…The rarefaction curves indicate that the sampling sufficiently captures the species in the study area. Unique taxa recorded in both disturbed and undisturbed areas indicated that the bacterial communities are most likely reflect by the environmental condition surrounding the host, which in this study is the anthropogenic factors (Nayak, 2010;Nolorbe-Payahua et al, 2020).…”

Hatchery tanks induce intense reduction in microbiota diversity associated with gills and guts of two endemic species of the São Francisco River

“…It is increasingly evident that microbiomes associated with wild animals provide these hosts with metabolic adaptations for survival in environments contaminated by recalcitrant pollutants and the consumption of toxic foods or those deteriorated by pathogens (Tarnecki et al, 2019;Levin et al, 2021). At the same time, some taxa can be characterized as possible biomarkers of environmental pollution (Caruso, 2016;Sylvain et al, 2016;Ventorino et al, 2018;Tarnecki et al, 2019;Nolorbe-Payahua et al, 2020). Cetobacterium, Aeromonas, and Plesiomonas also enriched SFR and HT fish microbiomes.…”

“…Characterizing microbiome composition could help craft ways to facilitate the functional enhancement of nutritional, immunologic, and other beneficial traits in reared fish (Perry et al, 2020). Studies involving fish have provided insights into the importance of microbiome associated with the skin, gills, and gut, allowing for the characterization of factors influencing microbial diversity in both wild and reared species; at least 145 fish gut microbiomes have been analyzed to date (Roeselers et al, 2011;Sylvain et al, 2016Sylvain et al, , 2019Tarnecki et al, 2016;Uren Webster et al, 2018;Krotman et al, 2020;Nolorbe-Payahua et al, 2020;Perry et al, 2020;Riiser et al, 2020). Nevertheless, most of these studies have been performed on economically relevant fish such as Cyprinus carpio (van Kessel et al, 2016), Ctenopharyngodon idellus (Wu et al, 2012), Salmo salar (Gajardo et al, 2016;Schmidt et al, 2016), Oreochromis niloticus (Yu et al, 2019;Xia et al, 2020), Oncorhynchus mykiss (Lowrey et al, 2015), Colossoma macropomum (Sylvain et al, 2016), Arapaimas gigas (Ramírez et al, 2018), Seriola lalandi (Legrand et al, 2018) and Ictalurus punctatus (Larsen et al, 2014).…”

El Hologenoma, una herramienta para el estudio de los problemas ambientales ocasionados por xenobióticos.

“…que cohabitan simbióticamente junto con las células del organismo pluricelular (Carrier y Reitzel, 2017). La evolución en las técnicas de detección de microorganismos durante las dos últimas décadas ha revelado que los organismos pluricelulares conviven con un número elevadísimo de microorganismos simbióticos, en algunos casos (como el humano) tan numeroso como las propias células somáticas (Nolorbe-Payahua, et al 2020), para tener un panorama más claro de esto último consideremos que el genoma humano contiene alrededor de 20.000 genes, pero su hologenoma contiene > 33 millones de genes aportados por su microbiota (Lloyd-Price et al, 2016).…”