Enhanced chromium and nitrogen removal by constructing a biofilm reaction system based on denitrifying bacteria preferential colonization theory.

Understanding the developmental characteristics of microbial communities in biofilms is crucial for designing targeted functional microbial enhancements for the remediation of complex contamination scenarios. The strong prioritization effect of microorganisms confers the ability to colonize strains that arrive first dominantly. In this study, the auto-aggregating denitrifying bacterial Pseudomonas stutzeri strain YC-34, which has both nitrogen and chromium removal characteristics, was used as a biological material to form a stable biofilm system based on the principle of dominant colonization and biofortification. The effect of the biofilm system on nitrogen and chromium removal was characterized by measuring the changes in the quality of influent and effluent water. The pattern of biofilm changes was analyzed by measuring biofilm content and thickness and characterizing extracellular polymer substances (EPS). Further analysis of the biofilm microbiota characteristics and potential functions revealed the mechanism of strain YC-34 biofortified biofilm. The results revealed that the biofilm system formed could achieve 90.56% nitrate-nitrogen removal with an average initial nitrate-nitrogen concentration of 51.9 mg/L and 40% chromium removal with an average initial hexavalent chromium Cr(VI) concentration of 7.12 mg/L. The biofilm properties of the system were comparatively analyzed during the biofilm formation period, the fluctuation period of Cr(VI)-stressed water quality, and the stabilization period of Cr(VI)-stressed water quality. The biofilm system may be able to increase the structure of hydrogen bonds, the type of protein secondary structure, and the abundance of amino acid-like components in the EPS, which may confer biofilm tolerance to Cr(VI) stress and allow the system to maintain a stable biofilm structure. Furthermore, microbial characterization indicated an increase in microbial diversity in the face of chromium stress, with an increase in the abundance of nitrogen removal-associated functional microbiota and an increasing trend in the abundance of nitrogen transfer pathways. These results demonstrate that the biofilm system is stable in nitrogen and chromium removal. This bioaugmentation method may provide a new way for the remediation of heavy metal-polluted water bodies and also provides theoretical and application parameters for the popularization and application of biofilm systems.

Nitrogen removal intensification of biofilm through bioaugmentation with Methylobacterium gregans DC-1 during wastewater treatment.

The increasing concern for environmental remediation has led to a search for effective methods to remove eutrophic nutrients. In this study, Methylobacterium gregans DC-1 was utilized to improve nitrogen removal in a sequencing batch biofilm reactor (SBBR) via aerobic denitrification. This bacterium has the extraordinary characteristics of strong auto-aggregation and a high ability to remove nitrogen efficiently, making it an ideal candidate for enhanced treatment of nitrogen-rich wastewater. This strain was used for the bioassessment of a test reactor (SBBRbio), which showed a shorter biofilm formation time compared to a control reactor (SBBRcon) without this strain inoculation. Moreover, the enhanced biofilm was enriched in TB-EPS and had a wider variety of protein secondary structures than SBBRcon. During the stabilization phase of SBBRbio, the EPS molecules showed the highest proportion of intermolecular hydrogen bonding. It is possible that bioaugmentation with this strain positively affects the structural stability of biofilm. At influent ammonia loadings of 100 and 150 mg. L-1, the average reduction of ammonia and nitrate-nitrogen was higher in the experimental system compared to the control system. Additionally, nitrite-N accumulation was lower and N2O production decreased compared to the control. Analysis of the microbial community structure demonstrated successful colonization in the bioreactor by a highly nitrogen-tolerant strain that efficiently removed inorganic nitrogen. These results illustrate the great potential of this type of denitrifying bacteria in the application of bioaugmentation systems.

Pleurotus ostreatus polysaccharide-mediated modulation of skin damage caused by microcystin-LR in tadpoles.

In this study, we aimed to evaluate the effect of dietary supplementation with edible mushroom (Pleurotus ostreatus)-derived polysaccharides on microcystin leucine-arginine (MC-LR)-induced skin damage in Pelophylax nigromaculatus tadpoles. Tadpoles were exposed to 1 µg/L daily MC-LR, with or without 5.0 g/kg of dietary P. ostreatus polysaccharides, for 30 days. P. ostreatus polysaccharide supplementation significantly increased the dermal collagen fibrils, increased tight junction protein gene expression, decreased the amount of MC-LR accumulation in skin tissues, attenuated oxidative stress, downregulated apoptosis-associated gene transcription, decreased eosinophil numbers, and downregulated transcription of inflammation-related genes (e.g. TLR4, NF-κB, and TNF-α). The composition of the skin commensal microbiota of MC-LR-exposed tadpoles supplemented with P. ostreatus polysaccharides was similar to that of the no-treatment control group. Lipopolysaccharide (LPS) content was positively correlated with the abundance of Gram-negative bacteria, including Chryseobacterium and Thauera. Therefore, P. ostreatus polysaccharides may alleviate MC-LR-induced skin barrier damage in tadpoles in two ways: 1) attenuation of oxidative stress-mediated apoptosis mediated by increased glutathione (GSH) content and total superoxide dismutase activity; and 2) alteration of the skin commensal microbiota composition to attenuate the LPS/Toll-like receptor 4 inflammatory pathway response. Furthermore, P. ostreatus polysaccharides may increase skin GSH synthesis by promoting glycine production via the gut microbiota and may restore the MC-LR-damaged skin resistance to pathogenic bacteria by increasing antimicrobial peptide transcripts and lysozyme activity. This study highlights for the first time the potential application of P. ostreatus polysaccharides, an ecologically active substance, in mitigating the skin damage induced by MC-LR exposure, and may provide new insights for its further development in aquaculture.

Protective effects of berberine in chronic copper-induced liver and gill injury in freshwater grouper (Acrossocheilus fasciatus).

This experiment aimed to investigate the protective effects of berberine on copper-induced liver and gill toxicities in freshwater grouper (Acrossocheilus fasciatus). Fish (initial weight 1.56 ± 0.10 g) were randomly distributed into 12 tanks (80 L, 20 fish per tank) and divided into four experimental groups: The control group, exposed to 0.02 mg/L Cu2+ (Cu group), exposed to 0.02 mg/L Cu2+ and fed 100 mg/kg berberine (BBR100 group), and exposed to 0.02 mg/L Cu2+ and fed 400 mg/kg berberine (BBR400 group). After a 30-day experiment, the results showed that berberine significantly increased the activities of catalase and glutathione peroxidase in the liver, gills, and serum inhibited by Cu2+ exposure (P < 0.05). Berberine inclusion significantly decreased the activities of lysozyme and acid phosphatase, as well as the content of immunoglobulin M compared to the Cu group (P < 0.05). Berberine significantly suppressed the expression of the proinflammatory cytokines interleukin-1ß, interleukin-6 signaling transducer, and NLR family pyrin domain containing 3 in the liver and gills induced by Cu2+ exposure while downregulating the expression of the anti-inflammatory cytokine transforming growth factor ß1. Additionally, berberine significantly reduced the activities of the liver injury markers alanine transaminase and aspartate transaminase, the levels of total cholesterol and triglyceride in serum, as well as alleviated the histopathological damage in the liver and gills caused by Cu2+ exposure. In summary, berberine enhanced antioxidant capacity, mitigated inflammation, and exerted significant protective effects on liver and gill damage in freshwater grouper under Cu2+ exposure.

Chronic environmentally relevant concentration of copper exposure induces intestinal oxidative stress, inflammation, and microbiota disturbance in freshwater grouper (Acrossocheilus fasciatus).

The influence of chronic environmentally relevant concentration of Cu2+ exposure on fish intestinal health has been rarely studied. In the present study, freshwater grouper (Acrossocheilus fasciatus) was subjected to 0 (control), 0.01 mg/L Cu2+ (Cu0.01), and 0.04 mg/L Cu2+ (Cu0.04) for 30 days. The Cu0.04 group obtained a significantly reduced survival rate, weight gain, and feed intake compared to the control group (P < 0.05). Both levels of Cu2+ exposure induced oxidative stress, evidenced by increased antioxidant enzymes' activities and malondialdehyde (MDA) contents in the intestine and serum. Based on 16S rDNA analysis, both levels of Cu2+ exposure significantly reduced intestinal microbiota community richness. In the Cu2+ exposure groups, Firmicutes/Bacteroidota ratio, and potentially pathogenic bacteria, such as Proteobacteria, genus Pseudomonas, Citrobacter, Shinella, and Aeromonas were enriched. Meanwhile, the richness of probiotic bacteria, such as Fusobacteriota, Planctomycetota, Cetobacterium, Gemmobacter, and Gemmata were significantly reduced by Cu2+ exposure. Both levels of Cu2+ exposure significantly reduced villus length, lamina propria width, and muscular thickness in the foregut and hindgut, but increased intestinal goblet cell numbers. 0.04 mg/L Cu2+ exposure significantly upregulated superoxide dismutase (sod), pro-inflammation genes nuclear factor kappa b subunit 1 (nfκb1) and interleukin 1 beta (il1ß) expression, but downregulated anti-inflammation gene transforming growth factor beta 1 (tgfß1) expression. In summary, chronic environmentally relevant concentrations of Cu2+ exposure induced intestinal oxidative stress, inflammation, prevalence of pathogen and inhibition of probiotic bacteria, and damage intestinal integrity of freshwater grouper.

Legacy and Emerging Per- and Polyfluoroalkyl Substances Surveillance in Bufo gargarizans from Inlet Watersheds of Chaohu Lake, China: Tissue Distribution and Bioaccumulation Potential.

Amphibians are sensitive biomonitors of environmental pollutants but reports regarding per- and polyfluoroalkyl substances (PFAS), a class of synthetic organofluorine substances, are limited. In this study, samples of water and Chinese toads (Bufo gargarizans) were collected in Chaohu Lake, China. Tissue-specific bioaccumulation characteristics of 39 PFAS, including 19 perfluoroalkyl acids (PFAAs), 8 emerging PFAS, and 12 PFAA precursors, were investigated, and the levels of some biochemical indicators were determined. The highest PFAS concentrations were found in the liver [215.97 ng/g dry weight (dw)] of Chinese toads, followed by gonads (135.42 ng/g dw) and intestine (114.08 ng/g dw). A similar tissue distribution profile was found between legacy and emerging PFAS in the toads, and the occurrence of two emerging PFAS, 2,3,3,3-tetrafluoro-2-propanoate (HFPO-DA) and 6:2 hydrogen-substituted polyfluorooctane ether sulfonate (6:2 H-PFESA) in the amphibians were for the first time reported. Field-based bioaccumulation factors of HFPO-DA were higher than perfluorooctanoic acid, indicating the higher bioaccumulation potential of this emerging PFAS than the legacy C8 compound. Males had significantly higher gonad PFAS levels than females while estradiol levels in gonads increased with increasing concentrations of certain PFAS (e.g., 6:2 H-PFESA), implying that PFAS may trigger estrogenic effects in the toads, especially for male toads.

Systematic investigation of simultaneous copper biosorption and nitrogen removal from wastewater by an aerobic denitrifying bacterium of auto-aggregation.

Finding effective methods for simultaneous removal of eutrophic nutrients and heavy metals has attracted increasing concerns for the environmental remediation. Herein, a novel auto-aggregating aerobic denitrifying strain (Aeromonas veronii YL-41) was isolated with capacities for copper tolerance and biosorption. The denitrification efficiency and nitrogen removal pathway of the strain were investigated by nitrogen balance analysis and amplification of key denitrification functional genes. Moreover, the changes in the auto-aggregation properties of the strain caused by extracellular polymeric substances (EPS) production were focused on. The biosorption capacity and mechanisms of copper tolerance during denitrification were further explored by measuring changes in copper tolerance and adsorption indices, as well as by variations in extracellular functional groups. The strain showed extremely strong total nitrogen removal ability, with 67.5%, 82.08% and 78.48% of total nitrogen removal when NH4+-N, NO2--N, and NO3--N were used as the only initial nitrogen source, respectively. The successful amplification of napA, nirK, norR, and nosZ genes further demonstrated that the strain accomplished nitrate removal through a complete aerobic denitrification pathway. The production of protein-rich EPS of up to 23.31 mg/g and an auto-aggregation index of up to 76.42% may confer a strong biofilm-forming potential to the strain. Under the stress of 20 mg/L copper ions, the removal of nitrate-nitrogen was still as high as 71.4%. In addition, the strain could achieve an efficient removal of 96.9% of copper ions at an initial concentration of 80 mg/L. Scanning electron microscopy and deconvolution analysis of characteristic peaks confirmed that the strains encapsulate heavy metals by secreting EPS and, meanwhile, form strong hydrogen bonding structures to enhance intermolecular forces to resist copper ion stress. This study provides an innovative and effective biological approach for the synergistic bioaugmentation removal of eutrophic substances and heavy metals from aquatic environments.

Diazulenorubicene as a Non-benzenoid Isomer of peri-Tetracene with Two Sets of 5/7/5 Membered Rings Showing Good Semiconducting Properties.

Non-benzenoid polycyclic aromatic hydrocarbons (PAHs) have received a lot of attention because of their unique optical, electronic, and magnetic properties, but their synthesis remains challenging. Herein, we report a non-benzenoid isomer of peri-tetracene, diazulenorubicene (DAR), with two sets of 5/7/5 membered rings synthesized by a (3+2) annulation reaction. Compared with the precursor containing only 5/7 membered rings, the newly formed five membered rings switch the aromaticity of the original heptagon/pentagon from antiaromatic/aromatic to non-aromatic/antiaromatic respectively, modify the intermolecular packing modes, and lower the LUMO levels. Notably, compound 2 b (DAR-TMS) shows p-type semiconducting properties with a hole mobility up to 1.27 cm2  V-1 s-1 . Moreover, further extension to larger non-benzenoid PAHs with 19 rings was achieved through on-surface chemistry from the DAR derivative with one alkynyl group.

The succession of gut microbiota in the concave-eared torrent frog (Odorrana tormota) throughout developmental history.

The gut microbiota of amphibians plays a crucial role in maintaining health and adapting to various developmental stages. The composition of gut microbial community is influenced by the phylogeny, habitat, diet, and developmental stage of the host. The present study analyzed the microbiota in the intestine of O. tormota at 11 developmental stages (from the tadpole at Gosner stage 24 to the 3-year-old adult) using high-throughput 16S rRNA sequencing. Alpha diversity index analysis of the microbiota revealed that the index decreased from tadpole at Gosner stage 24 to adult frog stage, remained stable during the adult frog stages, but increased significantly at the early metamorphosis and hibernation preparation stages. The gut microbiota structure is similar in adult frogs but differs significantly in other developmental stages. Furthermore, the dominant phyla of gut microbiota in tadpoles were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes, whereas those in adult frogs were Proteobacteria, Firmicutes, Bacteroidetes, and Verrucomicrobia. Host and environmental factors jointly affected the gut microbial diversity and community composition of O. tormota, but developmental stage, feeding habit, and habitat type had a more significant influence. The microbial community in the gut varies with the developmental stage of the host and constantly adapts to the survival requirements of the host. These findings advance our understanding of the evolutionary mechanism of amphibian gut microbiota in maintaining health homeostasis and adaptation.

High-Efficiency Narrowband Multi-Resonance Emitter Fusing Indolocarbazole Donors for BT. 2020 Red Electroluminescence and Ultralong Operation Lifetime.

Polycyclic heteroaromatics with multi-resonance (MR) characteristics are attractive materials for narrowband emitters in wide-color-gamut organic light-emitting diodes. However, MR emitters with pure-red colors are still rare and usually exhibit problematic spectral broadening when redshifting emission. Here, a narrowband pure-red MR emitter is reported by fusing indolocarbazole segments into a boron/oxygen-embedded skeleton, realizing BT.2020 red electroluminescence for the first time together with a high efficiency and an ultralong lifetime. The rigid indolocarbazole segment possesses a strong electron-donating ability due to its para-positioned nitrogen-π-nitrogen backbone and also enlarges the π-extension of the MR skeleton to suppress structural displacement during radiation, achieving concurrently redshifted and narrowed emission spectrum. An emission maximum at 637 nm with a full width at half-maxima of merely 32 nm (0.097 eV) is recorded in toluene. The corresponding device simultaneously exhibits CIE coordinates of (0.708, 0.292) precisely matching the BT.2020 red point, a high external quantum efficiency of 34.4% with low roll-off and an ultralong LT95 (time to 95% of the initial luminance) of >10 000 h at 1000 cd m-2 . These performance characteristics are superior even to those of state-of-the-art perovskite and quantum-dot-based devices for this specific color, paving the way toward practical applications.

Microcystin-leucine arginine causes brain injury and functional disorder in Lithobates catesbeianus tadpoles by oxidative stress and inflammation.

Microcystin-leucine arginine (MC-LR) is a toxin commonly found in eutrophic waters worldwide, but its potential effects on amphibian brain toxicity and exposure mechanisms are unclear. In this study, Lithobates catesbeianus tadpoles were exposed to MC-LR for 30 days at realistic ambient concentrations (0, 0.5, and 2 µg/L) to reveal its effects on brain health. The MC-LR bioaccumulation in the brain increased in dependence on the concentration of MC-LR exposure. Exposure to 0.5 and 2 µg/L MC-LR resulted in a significant down-regulation of the expression of structural components of the blood-brain barrier (CLDN1), while the expression of genes associated with inflammation (NLRP3, TNF, IL-1ß, and CXCL12) was significantly up-regulated with increased number of eosinophils. In the hippocampal and hypothalamic regions, the number of vacuolated neuropils increased with increasing MC-LR exposure concentration, while the expression of genes associated with neuronal development (LGALS1, CACNA2D2, and NLGN4X) and neurotransmitter transmission (SLC6A13 and AChE) was significantly down-regulated. Moreover, the levels of neurotransmitters (5-HT, glutamate, GABA, and ACh) were significantly reduced. These results provide strong evidence that MC-LR exposure at realistic ambient concentrations of 0.5 and 2 µg/L can break the blood-brain barrier and raise the accumulation of MC-LR in the brain tissue, causing structural damage and functional disorder to brain neurons. Further, based on transcriptomic and biochemical analysis, it was revealed that MC-LR exposure induces DNA damage through oxidative stress and may be an important pathway causing brain structural damage and functional disorder. Overall, this study demonstrates the significant effects of MC-LR on the brain tissue of amphibians, highlighting the sensitivity of amphibians to MC-LR.

Gill Junction Injury and Microbial Disorders Induced by Microcystin-Leucine Arginine in Lithobates catesbeianus Tadpoles.

Microcystin-LR (MC-LR) is widely present in waters around the world, but its potential toxic effects and mechanisms on amphibian gills remain unknown. In the present study, tadpoles (Lithobates catesbeianus) were exposed to environmentally realistic concentrations of 0.5, 2 µg/L MC-LR, and 0 µg/L MC-LR (Control) for 30 days with the objective to unveil the impairment of gill health. The lysozyme was downregulated, while pattern recognition receptors and complement and adaptive immune processes were upregulated and the ability of gill supernatant to inhibit pathogenic bacteria decreased in the 0.5 and 2 µg/L MC-LR groups. The transcriptions of epithelial barrier components (e.g., CLDN1) were significantly decreased in MC-LR-exposed gills, while the gill content of lipopolysaccharide (LPS) endotoxins and the transcriptions of downstream responsive genes (e.g., TLR4 and NF-κB) were concurrently increased. In addition, the number of eosinophils and the expression of pro-inflammatory cytokines (e.g., IL-1ß and TNF-α) were increased. These results imply that exposure of tadpoles to low environmentally concentrations of MC-LR leads to inflammation, increased permeability, and a reduced ability to inhibit pathogenic bacteria. The epithelial cells of inner gill filaments increased and transcriptions of hypoxic stress genes (e.g., HIF-1α, FLT1, and SERPINE1) were upregulated within the exposed group. As a consequence, exposure to MC-LR may lead to hypoxic stress. MC-LR exposure also drove gill microbiota to a dysbiosis. The relative abundance of Elizabethkingia was positively correlated with content of LPS and transcriptions of NF-κB and TNF-α. Overall, this study presents the first evidence about the pronounced impacts of MC-LR exposure on gills of amphibians, highlighting the susceptibility of early developing tadpoles to the environmental risks of MC-LR.

Microcystin-leucine arginine induces skin barrier damage and reduces resistance to pathogenic bacteria in Lithobates catesbeianus tadpoles.

Despite the importance of the skin mucosal barrier and commensal microbiota for the health of amphibians, the potential of environmental contaminants to disrupt the skin mucosal barrier and microbiota have rarely been studied in toxicology. In this study, tadpoles (Lithobates catesbeianus) were exposed to 0, 0.5, and 2 µg/L of microcystin-leucine arginine (MC-LR) for 30 days to explore the impacts of environmentally realistic MC-LR concentrations on the physical skin barrier, immune barrier, commensal microbiota, and skin resistance to pathogenic bacterial invasion. MC-LR exposure significantly reduced the collagen fibrils in the dermis of skin tissues and down-regulated tight junction and stratum corneum-related gene transcriptions, suggesting the damage caused by MC-LR to the physical barrier of the skin. Increased skin eosinophils and upregulated transcriptions of inflammation-related genes in the exposed tadpoles underline the development of skin inflammation resulting from MC-LR exposure even at environmentally realistic concentrations. Comparative transcriptome and immunobiochemical analyses found that antimicrobial peptides (Brevinin-1PLc, Brevinin-2GHc, and Ranatuerin-2PLa) and lysozyme were down-regulated in the exposed groups, while complement, pattern recognition receptor, and specific immune processes were up-regulated. However, the content of endotoxin lipopolysaccharide produced by bacteria increased in a dose-dependent pattern. The disc diffusion test showed a reduced ability of skin supernatant to inhibit pathogenic bacteria in the exposed groups. Analysis of microbial 16 S rRNA gene by high-throughput sequencing revealed that MC-LR interfered with the abundance, composition, and diversity of the skin commensal microbiota, which favored the growth of pathogen-containing genera Rhodococcus, Acinetobacter, and Gordonibacter. In summary, the current study provides the first clues about the impact of MC-LR on the integrity and function of skin barrier of amphibians. These new toxicological evidences can facilitate a more comprehensive evaluation of the ecological risk of MC-LR to amphibians.

Effects of chronic exposure to microcystin-LR on life-history traits, intestinal microbiota and transcriptomic responses in Chironomus pallidivittatus.

Microcystins (MCs) are the most widely distributed cyanobacterial toxins that can exert adverse effects on aquatic organisms, but aside from the study of the harmful effect of cyanobacterial blooms, little is known about the effect of released MCs on the growth and development of chironomid larvae. To assess the harmful effect and the toxic mechanism of MCs on midges, the life-history traits, intestinal microbiota, and transcriptome of Chironomus pallidivittatus were analyzed after chronic exposure to 30 µg/L of MC-LR. Exposure inhibited larvae body length by 35.61% and wet weight by 21.92%, increased emergence time of midges, damaged mitochondria in the intestine, promoted oxidative stress, dysregulated lipid metabolism of chironomid larvae, and increased detoxification enzymes glutathione S-transferase (GST) and superoxide dismutase (SOD) by 32.44% and 17.41%, respectively. Exposure also altered the diversity and abundance of the intestinal microbiota, favoring pathogenic and MC degradation bacteria. RNA sequencing identified 261 differentially expressed genes under MC-LR stress, suggesting that impairment of the peroxisome proliferator-activated receptor signaling pathway upregulated fatty acid biosynthesis and elongation to promote lipid accumulation. In addition, exposure-induced detoxification and antioxidant responses, indicating that the chironomid larvae had the potential ability to resist MC-LR. To our knowledge, this is the first time that lipid accumulation, oxidative stress, and detoxification have been studied in this organism at the environmentally relevant concentration of MC-LR; the information may assist in ecological risk assessment of cyanobacterial toxins and their effects on benthic organisms.

White Emissions Containing Room Temperature Phosphorescence from Different Excited States of a D-π-A Molecule Depending on the Aggregate States.

Development of pure organic molecular materials with room temperature phosphorescence (RTP) and their applications for white emitters have received significant attentions recently. Herein, a D-π-A molecule (DMACPPY) which can realize white emitting under ambient conditions both in the crystal state and the doped-film state by combining RTP with two fluorescent emissions is reported. The white emission from the crystalline sample of DMACPPY consists fluorescence from S2 (the second excited singlet state) and S1 (the first excited singlet state) along with RTP from T1 (the first excited triplet state), namely, SST-type white light. While, the white emission from the poly methyl methacrylate (PMMA) film doped with DMACPPY contains fluorescences from S2 and S1 , and RTP from T2 (the second excited triplet state) rather than T1 (STS type). DMACPPY cannot exhibit white spectrum within alternative crystalline state since inferior RTP intensity despite similar ternary emissions. The results demonstrate that the emissive properties for excited states of DMACPPY can be tuned by changing the aggregate state from crystalline to dispersion state in PMMA film. This new RTP emitter fulfills the talent for white emitting and achieves dual-mode white emissions, invisibly, expands the application range for pure organic and heavy atom-free RTP materials.

Risk and protection strategies of Amolops wuyiensis intestine against gastrointestinal nematode (Cosmocercoides wuyiensis n. sp.) infection.

Anuran amphibians are susceptible to infection by intestinal nematodes, but the damage and response mechanisms that occur in their intestines after infection are only partially understood. In this study, the intestinal disruption and response mechanisms in Amolops wuyiensis frogs infected with Cosmocercoides wuyiensis n. sp. were revealed through analysis of the intestinal histopathology, digestive enzyme activity, transcriptome and intestinal microbiota. Tissue section analysis showed histological damage and inflammation in the infected intestine, and the digestive enzyme activity indicated a decrease in digestion and absorption of some nutrients. We found that infection led to differences in the intestinal microbiota composition, including lower diversity and symbiotic relationships. The greater relative abundance of the genera Burkholderia and Rhodococcus may enhance intestinal immunity to resist pathogenic infections. A comparison of the transcriptomes of infected and uninfected intestines revealed 1055 differentially expressed genes. GO enrichment and KEGG pathways analyses suggested that the guts of infected C. wuyiensis n. sp. show enhanced complement activation, cell adhesion molecule function, NOD-like receptor signalling pathway activity and other innate immunity responses. Among the adaptive immune responses, the intestinal immune network for IgA production was significantly enriched, and the expression of IL-17D and transforming growth factor beta-1 genes were upregulated in the infected intestine. These results imply that C. wuyiensis n. sp. infection of A. wuyiensis intestine may trigger innate and adaptive immune responses, which reduce the post-infection burden. Furthermore, the intestine of A. wuyiensis may also respond to C. wuyiensis n. sp. infection by increasing metallocarboxypeptidase activity and accelerating smooth muscle contraction.

Microcystin-leucine arginine exposure induced intestinal lipid accumulation and MC-LR efflux disorder in Lithobates catesbeianus tadpoles.

Few studies exist on the toxic effects of chronic exposure to microcystins (MCs) on amphibian intestines, and the toxicity mechanisms are unclear. Here, we evaluated the impact of subchronic exposure (30 days) to environmentally realistic microcystin-leucine arginine (MC-LR) concentrations (0 µg/L, 0.5 µg/L and 2 µg/L) on tadpole (Lithobates catesbeianus) intestines by analyzing the histopathological and subcellular microstructural damage, the antioxidative and oxidative enzyme activities, and the transcriptome levels. Histopathological results showed severe damage accompanied by inflammation to the intestinal tissues as the MC-LR exposure concentration increased from 0.5 µg/L to 2 µg/L. RNA-sequencing analysis identified 634 and 1,147 differentially expressed genes (DEGs) after exposure to 0.5 µg/L and 2 µg/L MC-LR, respectively, compared with those of the control group (0 µg/L). Biosynthesis of unsaturated fatty acids and the peroxisome proliferator-activated receptor (PPAR) signaling pathway were upregulated in the intestinal tissues of the exposed groups, with many lipid droplets being observed on transmission electron microscopy, implying that MC-LR may induce lipid accumulation in frog intestines. Moreover, 2 µg/L of MC-LR exposure inhibited the xenobiotic and toxicant biodegradation related to detoxification, implying that the tadpoles' intestinal detoxification ability was weakened after exposure to 2 µg/L MC-LR, which may aggravate intestinal toxicity. Lipid accumulation and toxin efflux disorder may be caused by MC-LR-induced endoplasmic reticular stress. This study presents new evidence that MC-LR harms amphibians by impairing intestinal lipid metabolism and toxin efflux, providing a theoretical basis for evaluating the health risks of MC-LR to amphibians.

Efficacy of auto-aggregating aerobic denitrifiers with coaggregation traits for bioaugmentation performance in biofilm-formation and nitrogen-removal.

To promote efficiency nitrogen-rich wastewater treatment from a sequencing batch biofilm reactor (SBBR), three aerobic denitrifiers (Pseudomonas mendocinaIHB602, Methylobacterium gregansDC-1 and Pseudomonas stutzeriIHB618) with dual-capacities of strong auto-aggregation and high nitrogen removal efficiency were studied. The aggregation index analysis indicated that coaggregation of the three strains co-existed was better when compared with one or two strains grown alone. Optimal coaggregation strains were used to bioaugmente a test reactor (SBBRT), which exhibited a shorter time for biofilm-formation than uninoculated control reactor (SBBRC). With different influent ammonia-N loads (150, 200 and 300 mg·L-1), the average ammonia-N and nitrate-N removal efficiency were all higher than that in SBBRC, as well as a lower nitrite-N accumulation. Microbial community structure analysis revealed coaggregation strains may successfully colonize in the bioreactor and be very tolerant of high nitrogen concentrations, and contribute to the high efficiency of inorganic nitrogen-removal and biofilm-formation.

Dynamic transcriptome and histomorphology analysis of developmental traits of hindlimb thigh muscle from Odorrana tormota and its adaptability to different life history stages.

BACKGROUND: Systematic studies on the development and adaptation of hindlimb muscles in anura amphibians are rare. Here, we integrated analysis of transcriptome and histomorphological data for the hindlimb thigh muscle of Odorrana tormota (concave-eared torrent frog) at different developmental stages, to uncover the developmental traits of hindlimb thigh muscle from O. tormota and its adaptability to different life history stages. RESULTS: The development of hindlimb thigh muscle from O. tormota has the following characteristics. Before metamorphosis, myogenous cells proliferate and differentiate into myotubes, and form 11 muscle groups at G41; Primary myofibers and secondary myofibers appeared during metamorphosis; 11 muscle groups differentiated continuously to form myofibers, accompanied by myofibers hypertrophy after metamorphosis; During the growth process of O. tormota from G42 to G46, there were differences between the sexes in the muscle groups that differentiate into muscle fibers, indicating that there was sexual dimorphism in the hindlimb thigh muscles of O. tormota at the metamorphosis stages. Some genes and pathways related to growth, development, and movement ability of O. tormota at different developmental stages were obtained. In addition, some pathways associated with adaptation to metamorphosis and hibernation also were enriched. Furthermore, integrated analysis of the number of myofibers and transcriptome data suggested that myofibers of specific muscle groups in the hindlimbs may be degraded through lysosome and ubiquitin pathways to transform into energy metabolism and other energy-related substances to meet the physiological needs of hibernation. CONCLUSIONS: These results provide further understanding the hindlimb thigh muscle development pattern of frogs and their adaption to life history stages.

Molecular mechanism of Chinese alligator (Alligator sinensis) adapting to hibernation.

Hibernation is a physiological state for Chinese alligators to cope with cold weather. In mammals, gene expression changes during hibernation and their regulatory mechanisms have been extensively studied, however, these studies in reptiles are still rare. Here, integrated analysis of messenger RNA (mRNA), microRNA (miRNA), and long noncoding RNA (lncRNA) reveals the molecular mechanisms of the hypothalamus, liver, and skeletal muscle in hibernating and active individuals. During hibernation, the number of genes increased in the hypothalamus, liver, and skeletal muscle was 585, 282, and 297, while the number of genes decreased was 215, 561, and 627, respectively, as compared with active individuals. Through Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis, the differential expressed genes were mainly enriched in DNA damage repair, biological rhythm, energy metabolism, myoprotein degradation, and other related items and pathways. Besides, 4740 miRNAs were identified in three tissues. Through the comprehensive analysis of miRNA and mRNA abundance profiles, 12,291, 6997, and 8232 miRNA-mRNA pairs all showed a negative correlation in the hypothalamus, liver, and skeletal muscle, respectively. Some miRNA target genes were related tobiological rhythm and energy metabolism, suggesting that miRNA may play an important role in the physiological metabolism of the hibernating adaptability of Chinese alligators. Moreover, 402, 230, and 130 differentially expressed lncRNAs were identified in the hypothalamus, liver, and skeletal muscle, respectively. The targeting relationship of four lncRNA-mRNA pairs were predicted, with the main function of target genes involved in the amino acid transportation. These results are helpful to further understand the molecular regulatory basis of the hibernation adaptation in Chinese alligators.