Metagenomic and Metabolomic Analysis of the Toxic Effects of Trichloroacetamide-Induced Gut Microbiome and Urine Metabolome Perturbations in Mice

Disinfection byproducts (DBPs) in drinking water have been linked to various diseases, including colon, colorectal, rectal, and bladder cancer. Trichloroacetamide (TCAcAm) is an emerging nitrogenous DBP, and our previous study found that TCAcAm could induce some changes associated with host–gut microbiota co-metabolism. In this study, we used an integrated approach combining metagenomics, based on high-throughput sequencing, and metabolomics, based on nuclear magnetic resonance (NMR), to evaluate the toxic effects of TCAcAm exposure on the gut microbiome and urine metabolome. High-throughput sequencing revealed that the gut microbiome’s composition and function were significantly altered after TCAcAm exposure for 90 days in Mus musculus mice. In addition, metabolomic analysis showed that a number of gut microbiota-related metabolites were dramatically perturbed in the urine of the mice. These results may provide novel insight into evaluating the health risk of environmental pollutants as well as revealing the potential mechanism of TCAcAm’s toxic effects

Identifying Health Effects of Exposure to Trichloroacetamide Using Transcriptomics and Metabonomics in Mice (Mus musculus)

Microarray-based transcriptomics and one-dimensional proton nuclear magnetic resonance (¹H NMR) based metabonomics approaches were employed to investigate the health effects of nitrogenous disinfection byproducts (N-DBPs) of trichloroacetamide (TCAcAm) on mice. Mice were exposed to TCAcAm at concentrations of 50, 500, and 5000 μg/L for 90 days, and hepatic transcriptome and serum metabonome and histopathological parameters were detected in comparison with those of control. TCAcAm esposures resulted in liver inflammation, weight loss (in 5000 ug/L TCAcAm group), and alterations in hepatic transcriptome and serum metabonome. Based on the differentially expressed genes and altered metabolites, several significant pathways were identified, which are associated with lipid, xenobiotics, amino acid and energy metabolism, and cell process. Moreover, integrative pathway analyses revealed that TCAcAm exposure in this study induced hepatotoxicity and cytotoxicity. These results also highlight the noninvasive prospect of transcriptomic and metabonomic approaches in evaluating the health risk of emerging N-DBPs

Correlations of Gut Microbial Community Shift with Hepatic Damage and Growth Inhibition of <i>Carassius auratus</i> Induced by Pentachlorophenol Exposure

Goldfish (<i>Carassius auratus</i>) were exposed to 0–100 μg/L pentachlorophenol (PCP) for 28 days to investigate the correlations of fish gut microbial community shift with the induced toxicological effects. PCP exposure caused accumulation of PCP in the fish intestinal tract in a time- and dose-dependent manner, while hepatic PCP reached the maximal level after a 21 day exposure. Under the relatively higher PCP stress, the fish body weight and liver weight were reduced and hepatic CAT and SOD activities were inhibited, demonstrating negative correlations with the PCP levels in liver and gut content (<i>R</i> < −0.5 and <i>P</i> < 0.05 each). Pyrosequencing of the 16S rRNA gene indicated that PCP exposure increased the abundance of Bacteroidetes in the fish gut. Within the Bacteroidetes phylum, the <i>Bacteroides</i> genus had the highest abundance, which was significantly correlated with PCP exposure dosage and duration (<i>R</i> > 0.5 and <i>P</i> < 0.05 each). Bioinformatic analysis revealed that <i>Bacteroides</i> showed quantitatively negative correlations with <i>Chryseobacterium</i>, <i>Microbacterium</i>, <i>Arthrobacter</i>, and <i>Legionella</i> in the fish gut, and the Bacteroidetes abundance, <i>Bacteroides</i> abundance, and Firmicutes/Bacteroidetes ratio played crucial roles in the reduction of body weight and liver weight under PCP stress. The results may extend our knowledge regarding the roles of gut microbiota in ecotoxicology

Pharmaceutical concentrations and mixture in SBRs.

<p>Pharmaceutical concentrations and mixture in SBRs.</p

The relative abundances of bacteria in sludge samples of stable stage at phylum level.

<p>The abundance is presented in terms of percentage in total effective bacterial sequences in each sample. The color bar indicates the range of the percentage of a phylum. The sum of all phyla and unclassified phylum is 100%.</p

Average removals of selected NSAIDs in the stable stage of each reactor.

<p>Average removals of selected NSAIDs in the stable stage of each reactor.</p

Relative activities of oxidizing enzymes in activated sludge during the stable stage.

<p>The enzyme activity of the control is regarded as 100%. The relative activity is presented in the percentage of enzyme activity value in samples with enzyme activity value in the control. The relative activity is over 100% indicating an increase of enzyme activity (compared to the control). The relative activity is less 100% indicating a decrease of enzyme activity (compared to the control). asterisks (*) indicating the statistical difference from the control (<i>p</i> < 0.05).</p

Average removal of COD, NH₄⁺–N and TN during stable stage of each reactor.

<p>Average removal of COD, NH₄⁺–N and TN during stable stage of each reactor.</p

Phosphite in Sedimentary Interstitial Water of Lake Taihu, a Large Eutrophic Shallow Lake in China

The seasonal occurrence and distribution of phosphite (HPO₃^2‑, P) in sedimentary interstitial water from Lake Taihu was monitored from 2011 to 2012 to better understand its possible link to P cycle in the eutrophic shallow lake. Phosphite concentrations ranged from < MDL to 14.32 ± 0.19 μg P/kg with a mean concentration of 1.58 ± 0.33 μg P/kg, which accounts for 5.51% total soluble P (TSP_s) in surficial sediments (0–20 cm). Spatially, the concentrations of sedimentary phosphite in the lake’s northern areas were relatively higher than those in the southern areas. Higher phosphite concentrations were always observed in seriously polluted sites. Generally, phosphite in the deeper layers (20–40 cm and 40–60 cm) showed minor fluctuations compared to that in the surficial sediments, which may be associated with the frequent exchange at the sediment–water interface. Phosphite concentrations in surficial or core sediments decreased as spring > autumn > summer > winter. Higher phosphite levels occurred in the areas with lower redox (Eh), higher P contents, and particularly when metal bonded with P to form Al–P_s and Ca–P_s. Phosphite may be an important media in the P biogeochemical cycle in Lake Taihu and contribute to its internal P transportation

Fate of artificial sweeteners through wastewater treatment plants and water treatment processes - Fig 3

<p><b>Concentration of ASs through the treatment process in October in five WWTPs</b> (Detailed data for other months are shown in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0189867#pone.0189867.s005" target="_blank">S5 Table</a>).</p