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Food Additives & Contaminants. Part A,... Jun 2024Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, causes enormous economic losses in the food and feed industries. Simple, rapid, low-cost, and quantitative...
Zearalenone (ZEN), a nonsteroidal estrogenic mycotoxin, causes enormous economic losses in the food and feed industries. Simple, rapid, low-cost, and quantitative analysis of ZEN is particularly urgent in the fields of food safety and animal husbandry. Using the bioluminescent bacterium T3, we propose a bioluminescence inhibition assay to evaluate ZEN levels quickly. The limit of detection (LOD), limit of quantification (LOQ), and quantitative working range of this bioluminescence inhibition assay were 0.1 µg/mL, 5 µg/mL, and 5-100 µg/mL, respectively. The concentration-response curve of the bioluminescence inhibition rate and ZEN concentration was plotted within the range 5 to 100 μg/mL, as follows: y = 0.0069x - 0.0190x + 7.9907 (R = 0.9943, y is luminescence inhibition rate, x is ZEN concentration). First, we used the bioluminescence inhibition assay to detect the remaining ZEN in samples treated with purified lactonohydrolase ZHD101. The bioluminescence inhibition assay results showed a strong correlation with the HPLC analysis. Furthermore, we successfully evaluated the overall toxicity of samples treated with purified peroxidase Prx and HO using the T3 bioluminescence inhibition assay. The results indicate that the degradation products of ZEN created by purified peroxidase Prx and HO showed little toxicity to T3. In this study, a simple, rapid, and low-cost assay method of zearalenone by bioluminescent T3 was developed. The bioluminescence inhibition assay could be used to estimate the efficiency of enzymatic degradation of ZEN.
PubMed: 38857317
DOI: 10.1080/19440049.2024.2363397 -
Scientific Reports Dec 2023The large use of fish meal/fish oil in carnivorous fish feeds is the main concern regarding environmental sustainability of aquaculture. Here, we evaluated the effects...
Growth performance, gut microbiota composition, health and welfare of European sea bass (Dicentrarchus labrax) fed an environmentally and economically sustainable low marine protein diet in sea cages.
The large use of fish meal/fish oil in carnivorous fish feeds is the main concern regarding environmental sustainability of aquaculture. Here, we evaluated the effects of an innovative diet, designed to be (1) environmentally sustainable by lowering the marine protein content while being (2) cost effective by using sustainable alternative raw materials with acceptable cost and produced on an industrial scale, on growth performance, gut microbiota composition, health and welfare of European sea bass (Dicentrarchus labrax), a key species of the Mediterranean marine aquaculture, reared in sea cages. Results show that the specific growth rate of fish fed the low marine protein diet was significantly lower than those fed conventional diet (0.67% vs 0.69%). Fatty acid profile of fillets from fish fed a low marine protein diet presented significant lower n-6 and higher n-3 content when compared to conventional ones. Then, a significant increase in the abundance of Vibrio and reduction of Photobacterium were found in the gut of fish fed with the low marine protein diet but effects on sea bass health needs further investigation. Finally, no major health and welfare alterations for fish fed the low marine protein diet were observed, combined with a potential slight benefit related to humoral immunity. Overall, these results suggest that despite the low marine protein diet moderately affects growth performance, it nevertheless may enhance environmental and economic sustainability of the sea bass aquaculture.
Topics: Animals; Bass; Gastrointestinal Microbiome; Diet; Fish Oils; Fatty Acids; Diet, Protein-Restricted; Animal Feed
PubMed: 38042956
DOI: 10.1038/s41598-023-48533-3 -
Applied and Environmental Microbiology Jun 2024Studying how phylogeny influences the composition and functions of microbiotas within animal hosts is essential for gaining insights into the connection between...
Studying how phylogeny influences the composition and functions of microbiotas within animal hosts is essential for gaining insights into the connection between genetics, ecology, and health in the animal kingdom. However, due to limited comprehensive studies, this influence remains unclear for many wild mammals, including Mexican pinnipeds. We employed 16S rRNA gene deep-sequencing to investigate the impact of phylogeny on the gut microbiota of four pinniped species inhabiting Mexican shores: the Pacific harbor seal (), the northern elephant seal (), the California sea lion (), and the Guadalupe fur seal (). Our results indicated that factors such as diets and shared life histories exerted more influence on microbiota composition than phylogeny alone. Notably, otariid species sharing similar life histories displayed greater microbiota similarity than phocids, which have distinct life histories and fewer microbiota similarities. Furthermore, harbor seals have more microbial similarities with the two otariid species than with elephant seals. Of particular concern, we observed a higher abundance of potentially pathogenic bacteria (e.g., and ) in harbor seals and Guadalupe fur seals compared to other pinnipeds. This finding could pose health threats to these species and nearby human populations.IMPORTANCEPinnipeds in Mexico host microbial communities that remain understudied. While several factors can influence microbiota composition, the role of phylogenetic relationships among these pinnipeds remains unclear due to limited knowledge of the microbiota in certain species. This study aimed to fill this gap by characterizing the composition and function of the gut microbiota in the four pinniped species that occur in Mexico. Our analysis reveals that shared diets and life histories contribute to similarities in the composition of gut microbial communities. This study also highlights the potential differences in the metabolic capabilities and adaptations within the gut microbiota of pinnipeds. Understanding how phylogeny impacts microbial communities enhances our insights into the evolutionary dynamics of marine mammals.
Topics: Animals; Gastrointestinal Microbiome; Phylogeny; Mexico; RNA, Ribosomal, 16S; Caniformia; Bacteria; Phoca; Fur Seals; Sea Lions; Seals, Earless
PubMed: 38771055
DOI: 10.1128/aem.02030-23 -
Journal of Bacteriology Mar 2024Although bacterial peptidoglycan (PG) is highly conserved, some natural variations in PG biosynthesis and structure have evolved. Understanding the mechanisms and limits...
UNLABELLED
Although bacterial peptidoglycan (PG) is highly conserved, some natural variations in PG biosynthesis and structure have evolved. Understanding the mechanisms and limits of such variation will inform our understanding of antibiotic resistance, innate immunity, and the evolution of bacteria. We have explored the constraints on PG evolution by blocking essential steps in PG biosynthesis in and then selecting mutants with restored prototrophy. Here, we attempted to select prototrophic suppressors of a D-glutamate auxotrophic mutant. No suppressors were isolated on unsupplemented lysogeny broth salts (LBS), despite plating >10 cells, nor were any suppressors generated through mutagenesis with ethyl methanesulfonate. A single suppressor was isolated on LBS supplemented with iso-D-gln, although the iso-D-gln subsequently appeared irrelevant. This suppressor has a genomic amplification formed by the creation of a novel junction that fuses to a gene encoding a putative road-pectrum acemase of , . An engineered allele lacking the putative secretion signal (ΔSS-) also suppressed D-glu auxotrophy, resulting in PG that was indistinguishable from the wild type. The ΔSS- allele similarly suppressed the D-alanine auxotrophy of an mutant and restored prototrophy to a double mutant auxotrophic for both D-ala and D-glu. The ΔSS- allele increased resistance to D-cycloserine but had no effect on sensitivity to PG-targeting antibiotics penicillin, ampicillin, or vancomycin. Our work helps define constraints on PG evolution and reveals a periplasmic broad-spectrum racemase in that can be co-opted for PG biosynthesis, with concomitant D-cycloserine resistance.
IMPORTANCE
D-Amino acids are used and produced by organisms across all domains of life, but often, their origins and roles are not well understood. In bacteria, D-ala and D-glu are structural components of the canonical peptidoglycan cell wall and are generated by dedicated racemases Alr and MurI, respectively. The more recent discovery of additional bacterial racemases is broadening our view and deepening our understanding of D-amino acid metabolism. Here, while exploring alternative PG biosynthetic pathways in , we unexpectedly shed light on an unusual racemase, BsrF. Our results illustrate a novel mechanism for the evolution of antibiotic resistance and provide a new avenue for exploring the roles of non-canonical racemases and D-amino acids in bacteria.
Topics: Glutamic Acid; Aliivibrio fischeri; Racemases and Epimerases; Cycloserine; Peptidoglycan; Amino Acids; Alanine Racemase
PubMed: 38411059
DOI: 10.1128/jb.00333-23 -
Foods (Basel, Switzerland) Dec 2023This study investigated the effect of sub-chilling whole gutted salmon and sub-chilled storage at -1 °C in modified-atmosphere packaging in two recyclable mono-material...
This study investigated the effect of sub-chilling whole gutted salmon and sub-chilled storage at -1 °C in modified-atmosphere packaging in two recyclable mono-material trays (CPET, HDPE). Quality parameters were measured, including water-holding properties, salt content, color, texture, lipid oxidation, and sensory and microbiological shelf life. The oxygen transmission rate was measured for the packages. Compared to traditional fish storage on ice, sub-chilling gave a 0.4% weight gain, better water-holding capacity, and higher salt content. The sub-chilled fish gave a significantly better sensory quality and microbiological shelf life of up to 49 days. Photobacterium was the dominating bacteria during storage. Salmon packaged in CPET trays had a higher drip loss than HDPE trays, but a lower rate of lipid oxidation (1-penten-3-ol). Our results showed the feasibility of significantly extending shelf life with sub-chilling, removing the need for ice. Moreover, using recyclable trays for packaging contributes to a circular economy without compromising food quality.
PubMed: 38201047
DOI: 10.3390/foods13010019 -
Foods (Basel, Switzerland) Apr 2024A novel storage technique that combines the low-frequency electric field (LFEF) and ice temperature was used to extend the shelf life of Pacific white shrimp (). The...
A novel storage technique that combines the low-frequency electric field (LFEF) and ice temperature was used to extend the shelf life of Pacific white shrimp (). The study investigated the effect of LFEF treatment on the quality and microbial composition of during storage at ice temperature. The results showed that the LFEF treatment significantly extended the shelf life of shrimp during storage at ice temperature. The total volatile base nitrogen (TVB-N) and pH of samples increased over time, while the total viable count (TVC) showed a trend of first decreasing and then increasing. Obviously, shrimp samples treated with LFEF had a lower pH, TVB-N and TVC values than the untreated samples ( < 0.05) at the middle and late stages of storage. LFEF treatment increased the diversity and altered the composition of the microbial communities in . Additionally, the treatment led to a decrease in the relative abundance of dominant spoilage bacteria, including , and , in stored at ice temperature for 11 days. Furthermore, correlation analysis indicated that TVB-N and pH had a significant and positive correlation with , suggesting that had a greater impact on shrimp quality. This study supports the practical application of accelerated low-frequency electric field-assisted shrimp preservation as an effective means of maintaining shrimp meat quality.
PubMed: 38672816
DOI: 10.3390/foods13081143 -
Marine Pollution Bulletin Jan 2024The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion...
Microplastics in the insular marine environment of the Southwest Indian Ocean carry a microbiome including antimicrobial resistant (AMR) bacteria: A case study from Reunion Island.
The increasing threats to ecosystems and humans from marine plastic pollution require a comprehensive assessment. We present a plastisphere case study from Reunion Island, a remote oceanic island located in the Southwest Indian Ocean, polluted by plastics. We characterized the plastic pollution on the island's coastal waters, described the associated microbiome, explored viable bacterial flora and the presence of antimicrobial resistant (AMR) bacteria. Reunion Island faces plastic pollution with up to 10,000 items/km in coastal water. These plastics host microbiomes dominated by Proteobacteria (80 %), including dominant genera such as Psychrobacter, Photobacterium, Pseudoalteromonas and Vibrio. Culturable microbiomes reach 10 CFU/g of microplastics, with dominance of Exiguobacterium and Pseudomonas. Plastics also carry AMR bacteria including β-lactam resistance. Thus, Southwest Indian Ocean islands are facing serious plastic pollution. This pollution requires vigilant monitoring as it harbors a plastisphere including AMR, that threatens pristine ecosystems and potentially human health through the marine food chain.
Topics: Humans; Indian Ocean; Microplastics; Plastics; Reunion; Bacteria; Microbiota; Environmental Monitoring; Water Pollutants, Chemical
PubMed: 38103498
DOI: 10.1016/j.marpolbul.2023.115911 -
Comparative Biochemistry and... Jun 2024A comprehensive bioinformatics analysis was conducted to elucidate the innate immune response of Charybdis japonica following exposure to Aeromonas hydrophila. This...
A comprehensive bioinformatics analysis was conducted to elucidate the innate immune response of Charybdis japonica following exposure to Aeromonas hydrophila. This study integrated metabolomics, 16S rRNA sequencing, and enzymatic activity data to dissect the immune mechanisms activated in response to infection. Infection with A. hydrophila resulted in an increased abundance of beneficial intestinal genera such as Photobacterium spp., Rhodobacter spp., Polaribacter spp., Psychrilyobacter spp., and Mesoflavibacter spp. These probiotics appear to suppress A. hydrophila colonization by competitively dominating the intestinal microbiota. Key metabolic pathways affected included fatty acid biosynthesis, galactose metabolism, and nitrogen metabolism, highlighting their role in the crab's intestinal response. Enzymatic analysis revealed a decrease in activities of hexokinase, phosphofructokinase, and pyruvate kinase, which are essential for energy homeostasis and ATP production necessary for stress responses. Additionally, reductions were observed in the activities of acetyl-CoA carboxylase and fatty acid synthase. Gene expression analysis showed downregulation in Peroxiredoxin 1 (PRDX1), Peroxiredoxin 2 (PRDX2), glutathione-S-transferase (GST), catalase (CAT), and glutathione (GSH), with concurrent increases in malondialdehyde (MDA) levels, indicating severe oxidative stress. This study provides insights into the molecular strategies employed by marine crabs to counteract bacterial invasions in their natural habitat.
Topics: Aeromonas hydrophila; Animals; Immunity, Innate; Brachyura; Gram-Negative Bacterial Infections; Metabolomics; Gastrointestinal Microbiome; Microbiota
PubMed: 38718732
DOI: 10.1016/j.cbd.2024.101240 -
The Science of the Total Environment Jan 2024Tire wear particles (TWPs) are widely distributed in natural water and pose as major pollutants in aquatic environments. In this study, heat-activated persulfate (HPT)...
Tire wear particles (TWPs) are widely distributed in natural water and pose as major pollutants in aquatic environments. In this study, heat-activated persulfate (HPT) and ultraviolet-activated persulfate treatments (UPT) were employed to investigate the influence of sulfate radical (SO•)-based advanced oxidation process (SAOPs) on TWP physicochemical properties and to clarify their ecotoxic effects in laboratory-level studies. Results showed that the specific surface areas of TWPs increased after UPT but decreased after HPT. In terms of chemical properties, the increase of oxygen-containing functional groups on the surfaces of TWPs was more evident in UPT than that in HPT. The atrazine (ATZ) adsorption capacity of TWPs after HPT and UPT was increased compared with the untreated TWPs. Atrazine adsorbed by TWPs was easily resolved and released in artificial intestinal fluid (1.89-2.08 mg/g) and artificial gastric fluid (1.60-2.04 mg/g) conditions. Acute toxicity experiments of Photobacterium phosphoreum and SEM-EDS detection results suggested that various heavy metals (e.g., Zn, Cu) in the TWPs would be released into the water system in SAOPs. ATZ released from TWPs that adsorbed ATZ herbicide, rather than TWPs themselves, had a negative effect on aquatic plant growth (e.g., C. vulgaris). The leaching solution of oxidized TWPs (after HPT and UPT) showed a more significant inhibition effect on the zebrafish survival compared with that of untreated TWPs, which was possibly caused by the generation of oxidation byproducts such as N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine-quinone.
Topics: Animals; Water Pollutants, Chemical; Atrazine; Zebrafish; Aging; Water
PubMed: 37778564
DOI: 10.1016/j.scitotenv.2023.167497 -
Environmental Research Jul 2024The sequencing electroreduction-electrooxidation process has emerged as a promising approach for the degradation of the chloronitrobenzenes (CNBs) due to its elimination...
The sequencing electroreduction-electrooxidation process has emerged as a promising approach for the degradation of the chloronitrobenzenes (CNBs) due to its elimination of electro-withdrawing groups in the reduction process, facilitating further removal in the subsequent oxidation process. Herein, we developed a cathode consisting of atom Pd on a Ti plate, which enabled the electro-generation of atomic hydrogen (H*) and the efficient electrocatalytic activation of HO to hydroxyl radical (•OH). Cyclic voltammetry (CV) curves and electron spin resonance (ESR) spectra verified the existence of H* and •OH. The electroreduction-electrooxidation system achieved 94.7% of 20 mg L 2,4-DCNB removal with a relatively low HO addition (5 mM). Moreover, the inhibition rate of Photobacterium phosphoreum in the effluent decreased from 95% to 52% after the sequencing electroreduction-electrooxidation processes. It was further revealed that the H* dominated the electroreduction process and triggered the electrooxidation process. Our work sheds light on the effective removal of electron-withdrawing groups substituted aromatic contaminants from water and wastewater.
Topics: Oxidation-Reduction; Wastewater; Water Pollutants, Chemical; Nitrobenzenes; Hydrogen; Electrochemical Techniques; Waste Disposal, Fluid
PubMed: 38663671
DOI: 10.1016/j.envres.2024.118986