Toxicity of perfluorooctane sulfonate on Phanerochaete chrysosporium: Growth, pollutant degradation and transcriptomics

Enhancement of PFAS stress tolerance and wastewater treatment efficiency by arbuscular mycorrhizal fungi in constructed wetlands

This study aims to explore the effects of arbuscular mycorrhizal fungi (AMF) on the growth of Iris pseudacorus L. and treatment efficacy in constructed wetlands (CWs) subjected to stress from per-and poly-fluoroalkyl substances (PFASs). The findings reveal that PFASs exposure induces oxidative damage and inhibits the growth of I. pseudacorus. However, AMF symbiosis enhances plant tolerance to PFAS stress by modulating oxidative responses. AMF treatment not only promoted plant growth but also improved photosynthetic efficiency under PFAS exposure. Compared to non-AMF treatment, those with AMF treatment exhibited significantly increased levels of peroxidases and antioxidant enzymes, including peroxidase and superoxide dismutase, along with a notable reduction in lipid peroxidation. Additionally, AM symbiosis markedly enhanced the efficacy of CWs in the remediation of wastewater under PFASs-induced stress, with removal efficiencies for COD, TP, TN, and NH4+-N increasing by 19-34%, 67-180%, 106-137%, and 25-95%, respectively, compared to the AMF- treatments. In addition, the metabolic pathways of PFASs appeared to be influenced by their carbon chain length, with long-chain PFASs like perfluorooctanoic acid (PFOA) and perfluoro anionic acid (PFNA) exhibiting more complex pathways compared to short-chain PFASs such as perfluoro acetic acid (PFPeA), and perfluoro hexanoic acid (PFHpA). These results suggest that AMF-plant symbiosis can enhance plant resilience against PFAS-induced stress and improve the pollutant removal efficiency of CWs. This study highlights the significant potential of AMF in enhancing environmental remediation strategies, providing new insights for the more effective management of PFAS-contaminated ecosystems.

White rot fungi as a multifaceted biocontrol agent: Metabolic disruption and algal inhibition in Microcystis aeruginosa

Microcystis aeruginosa is a prevalent cyanobacterium linked to water eutrophication and harmful algal blooms. While bacterial control strategies are well-studied, the effects of white rot fungi on Microcystis aeruginosa are less understood. This study examines the impact of whole fungal liquid, its centrifuged supernatant, and sterilized solutions on the algae's physiological and biochemical traits. Metabolomics and multivariate analysis identified significant changes in 47 metabolic markers, including carbohydrates, amino acids, and fatty acids, across treatments. The complete fungal liquid exhibited the strongest algicidal effect, likely due to synergistic solubilization mechanisms mediated by extracellular enzymes such as manganese peroxidase, catalase, and laccase. Notably, algicidal activity persisted even after sterilization, suggesting the presence of non-proteinaceous compounds like polysaccharides or lipids. The metabolic disturbances included downregulation of the TCA cycle and reduced fatty acid synthesis, leading to inhibited photosynthesis and compromised nucleic acid integrity in the algal cells. This research enhances our understanding of how white rot fungi disrupt Microcystis aeruginosa metabolism, providing a theoretical basis for their potential use in bioremediation of eutrophic aquatic environments.

Sub-acute exposure of male guppies (Poecilia reticulata) to environmentally relevant concentrations of PFOA and GenX induces significant changes in the testis transcriptome and reproductive traits

Poly- and perfluoroalkyl substances (PFAS) are frequently detected in the environment and are linked to adverse reproductive health outcomes in humans. Although legacy PFAS have been phased out due to their toxicity, alternative PFAS are increasingly used despite the fact that information on their toxic effects on reproductive traits is particularly scarce. Here, we exposed male guppies (Poecilia reticulata) for a short period (21 days) to an environmentally realistic concentration (1 ppb) of PFOA, a legacy PFAS, and its replacement compound, GenX, to assess their impact on reproductive traits and gene expression. Exposure to PFAS did not impair survival but instead caused sublethal effects. Overall, PFAS exposure caused changes in male sexual behaviour and had detrimental effects on sperm motility. Sublethal variations were also seen at the transcriptional level, with the modulation of genes involved in immune regulation, spermatogenesis, and oxidative stress. We also observed bioaccumulation of PFAS, which was higher for PFOA than for GenX. Our results offer a comprehensive comparison of these two PFAS and shed light on the toxicity of a newly emerging alternative to legacy PFAS. It is therefore evident that even at low concentrations and with short exposure, PFAS can have subtle yet significant effects on behaviour, fertility, and immunity. These findings underscore the potential ramifications of pollution under natural conditions and their impact on fish populations.

Metabolic and Microbial Profiling of Soil Microbial Community under Per- and Polyfluoroalkyl Substance (PFAS) Stress

Per- and polyfluoroalkyl substances (PFAS) represent significant stress to organisms and are known to disrupt microbial community structure and function. Nevertheless, a detailed knowledge of the soil microbial community responding to PFAS stress at the metabolism level is required. Here we integrated UPLC-HRMS-based metabolomics data with 16S rRNA and ITS amplicon data across soil samples collected adjacent to a fluoropolymer production facility to directly identify the biochemical intermediates in microbial metabolic pathways and the interactions with microbial community structure under PFAS stress. A strong correlation between metabolite and microbial diversity was observed, which demonstrated significant variations in soil metabolite profiles and microbial community structures along with the sampling locations relative to the facility. Certain key metabolites were identified in the metabolite-PFAS co-occurrence network, functioning on microbial metabolisms including lipid metabolism, amino acid metabolism, and secondary metabolite biosynthesis. These results provide novel insights into the impacts of PFAS contamination on soil metabolomes and microbiomes. We suggest that soil metabolomics is an informative and useful tool that could be applied to reinforce the chemical evidence on the disruption of microbial ecological traits.

Removal of perfluorooctanoic acid (PFOA) in the liquid culture of Phanerochaete chrysosporium

Perfluorooctanoic acid (PFOA) is becoming a concern due to its persistence, bioaccumulation, and potential harmful effects on humans and the environment. In this study, the fungus Phanerochaete chrysosporium (P. chrysosporium) was used to remove the PFOA in liquid culture system. The results showed that the average activities of laccase (Lac), lignin peroxidase (LiP), and manganese peroxidase (MnP) enzymes secreted by P. chrysosporium were 0.0003 U/mL, 0.013 U/mL, and 0.0059 U/mL, respectively, during the incubation times of 0-75 days. The pH of 3 and incubation time of 45-55 days were the optimum parameters for the three enzymes activities. The enzyme activities in P. chrysosporium incubation system were firstly inhibited by adding PFOA and then they were enhanced after 14 days. The maximum removal efficiency of PFOA (69.23%) was achieved after 35 days in P. chrysosporium incubation system with an initial PFOA concentration of 0.002 mM and no veratryl alcohol (VA). Adsorption was not a main pathway for PFOA removal and the PFOA adsorbed in fungi mycelial mat accounted for merely 1.91%. The possible products of PFOA contained partially fluorinated aldehyde, alcohol, and aromatic ring. These partially fluorinated compounds might result from PFOA degradation via a combination of cross-coupling and rearrangement of free radicals.

Bisphenols and perfluoroalkyls alter human stem cells integrity: A possible link with infertility

Bisphenols and Perfluoroalkyls are chemical compounds widely used in industry known to be endocrine disruptors (EDs). Once ingested through contaminated aliments, they mimic the activity of endogenous hormones leading to a broad spectrum of diseases. Due to the extensive use of plastic in human life, particular attention should be paid to antenatal exposure to Bisphenols and Perfluoroalkyls since they cross the placental barrier and accumulates in developing embryo. Here we investigated the effects of Bisphenol-A (BPA), Bisphenol-S (BPS), perfluorooctane-sulfonate (PFOS) and perfluorooctanoic-acid (PFOA), alone or combined, on human-induced pluripotent stem cells (hiPSCs) that share several biological features with the stem cells of blastocysts. Our data show that these EDs affect hiPSC inducing a great mitotoxicity and dramatic changes in genes involved in the maintenance of pluripotency, germline specification, and epigenetic regulation. We also evidenced that these chemicals, when combined, may have additive, synergistic but also negative effects. All these data suggest that antenatal exposure to these EDs may affect the integrity of stem cells in the developing embryos, interfering with critical stages of early human development that might be determinant for fertility. The observation that the effects of exposure to a combination of these chemicals are not easily foreseeable further highlights the need for wider awareness of the complexity of the EDs effects on human health and of the social and economic burden attributable to these compounds.

The Effects of Combined Exposure to Bisphenols and Perfluoroalkyls on Human Perinatal Stem Cells and the Potential Implications for Health Outcomes

The present study investigates the impact of two endocrine disruptors, namely Bisphenols (BPs) and Perfluoroalkyls (PFs), on human stem cells. These chemicals leach from plastic, and when ingested through contaminated food and water, they interfere with endogenous hormone signaling, causing various diseases. While the ability of BPs and PFs to cross the placental barrier and accumulate in fetal serum has been documented, the exact consequences for human development require further elucidation. The present research work explored the effects of combined exposure to BPs (BPA or BPS) and PFs (PFOS and PFOA) on human placenta (fetal membrane mesenchymal stromal cells, hFM-MSCs) and amniotic fluid (hAFSCs)-derived stem cells. The effects of the xenobiotics were assessed by analyzing cell proliferation, mitochondrial functionality, and the expression of genes involved in pluripotency and epigenetic regulation, which are crucial for early human development. Our findings demonstrate that antenatal exposure to BPs and/or PFs may alter the biological characteristics of perinatal stem cells and fetal epigenome, with potential implications for health outcomes at birth and in adulthood. Further research is necessary to comprehend the full extent of these effects and their long-term consequences.

Antenatal Exposure to Plastic Pollutants: Study of the Bisphenols and Perfluoroalkyls Effects on Human Stem Cell Models

Endocrine disruptors (EDs), such as Bisphenols (BPs) and Perfluoroalkyls (PFs), are a class of plastic pollutants widely used in industrial applications. Human exposure to these molecules usually occurs through ingestion of contaminated food and water. Once entered the human body they can interfere with endogenous hormone signaling, leading to a wide spectrum of diseases. It has been reported that BPs and PFs can cross the placental barrier accumulating in the fetal serum, but the detrimental consequences for human development remain to be clarified. Here we analyze the effects of different doses of bisphenol A and S (BPA, BPS) perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) on proliferation and mitochondrial health on different types of stem cells: through an integrated approach that combines data from pluripotent stem cells (hiPSCs) with that from the “environment” in which the embryo develops (fetal annexes-derived perinatal stem cells) we verified the potential developmental toxicity of the in utero EDs exposure. Data obtained showed that overall, BPs, and PFs tended to increase the proliferation rate of perinatal stem cells; a similar response was observed in hiPSCs exposed to very low doses of BPs and PFs, while at higher concentrations these chemicals were toxic; in addition, both the BPs and the PFs exerted a mitotoxic effects hiPSCs at all the concentration studied. All these data suggest that antenatal exposure to BPs and PFs, also at very low concentrations, may modify the biological characteristics of stem cells present in both the developing fetus and the fetal annexes, thus perturbing normal human development.

Synergistic degradation of Azure B and sulfanilamide antibiotics by the white-rot fungus Trametes versicolor with an activated ligninolytic enzyme system

The treatment of complex polluted wastewater has become an increasingly critical concern for the various types of hazardous organic compounds, including synthetic dyes and pharmaceuticals. Due to their efficient and eco-friendly advantages, the white-rot fungi (WRF) have been applied to degrade environmental pollutants. This study aimed to investigate the removal ability of WRF (i.e., Trametes versicolor WH21) in the co-contamination system composed of Azure B dye and sulfacetamide (SCT). Our study discovered that the decolorization of Azure B (300 mg/L) by strain WH21 was significantly improved (from 30.5% to 86.5%) by the addition of SCT (30 mg/L), while the degradation of SCT was also increased from 76.4% to 96.2% in the co-contamination system. Transcriptomic and biochemical analyses indicated that the ligninolytic enzyme system was activated by the enhanced enzymatic activities of MnPs and laccases, generating higher concentration of extracellular H₂O₂ and organic acids in strain WH21 in response to SCT stress. Purified MnP and laccase of strain WH21 were revealed with remarkable degradation effect on both Azure B and SCT. These findings significantly expanded the existing knowledge on the biological treatment of organic pollutants, indicating the strong promise of WRF in the treatment of complex polluted wastewater.

Repairing of rutin to the toxicity of combined F-53B and chromium pollution on the biofilm formed by Pseudomonas aeruginosa

The wastewater discharge from the process of chrome plating, which contains 6:2 chlorinated polyfluorinated ether sulfonate (F-53B) and chromium (Cr), may be toxic to biofilm. In this study we found that the biofilm formed by Pseudomonas aeruginosa PAO1 was inhibited by exposure to a combination of F-53B and Cr(VI). The combined pollution damaged the cell membranes and the structure of the biofilm, and inhibited the production of the Pseudomonas quinolone-based signal, which affected biofilm formation. Moreover, the secretion of extracellular polymeric substances decreased as a result of this combined exposure. Exposure to F-53B and Cr(VI) individually or in combination could induce the excessive accumulation of intracellular reactive oxygen species (ROS), and the ROS positive rate of the bacteria increased under the treatment with 0.2 mmol/L of Cr(VI) and 250 nmol/L of F-53B, respectively. In addition, the activities of superoxide dismutase (SOD) and catalase (CAT) were enhanced for scavenging ROS in the bacteria that were exposed to Cr(VI) and F-53B. As an antioxidant, rutin was used to repair the toxicity of Cr(VI) and F-53B towards the biofilm formed by the bacteria. When rutin was added to the bacteria medium, with either Cr(VI) or F-53B as pollutant, or with the combined pollutants, the extracellular protein content of the bacteria recovered to 0.84, 0.94, and 0.85 times that of the control, respectively. Meanwhile, the accumulation of ROS and the activities of SOD and CAT decreased, which indicated that the addition of rutin can alleviate the oxidative stress and promote the antioxidant stress system.

Persistent organic pollutants in model fungal membranes. Effects on the activity of phospholipases

Soils are the final sink for multiple organic pollutants emitted to the environment. Some of these chemicals which are toxic, recalcitrant and can bioaccumulate in living organism and biomagnify in trophic chains are classified persistent organic pollutants (POP). Vast areas of arable land have been polluted by POPs and the only economically possible means of decontamination is bioremediation, that is the utilization of POP-degrading microbes. Especially useful can be non-ligninolytic fungi, as their fast-growing mycelia can reach POP molecules strongly bond to soil minerals or humus fraction inaccessible to bacteria. The mobilized POP molecules are incorporated into the fungal plasma membrane where their degradation begins. The presence of POP molecules in the membranes can change their physical properties and trigger toxic effects to the cell. To avoid these phenomena fungi can quickly remodel the phospholipid composition of their membrane with employing different phospholipases and acyltransferases. However, if the presence of POP downregulates the phospholipases, toxic effects and the final death of microbial cells are highly probable. In our studies we applied multicomponent Langmuir monolayers with their composition mimicking fungal plasma membranes and studied their interactions with two different microbial phospholipases: phospholipase C (α-toxin) and phospholipase A1 (Lecitase ultra). The model membranes were doped with selected POPs that are frequently found in contaminated soils. It turned out that most of the employed POPs do not downregulate considerably the activity of phospholipases, which is a good prognostics for the application of non-ligninolytic fungi in bioremediation.

Toxicity evaluation of decabromodiphenyl ethane (DBDPE) to Pleurotus ostreatus: Oxidative stress, morphology and transcriptomics

Decabromodiphenyl ethane (DBDPE), one widely used new brominated flame retardant, was of great concern due to its biotoxicity. The toxic evaluation of DBDPE (1-50 mg/L) to white-rot fungus (Pleurotus ostreatus), including oxidative stress, morphology and transcriptomics was conducted aiming at improving its biodegradation. Fungal growth and ATPase activity were obviously inhibited by DBDPE at ≥ 10 mg/L with the exposure from 48 h to 96 h. DBDPE could induce oxidative stress to P. ostreatus. The activity of SOD (superoxide dismutase), CAT (catalase) and GSH (glutathione) were all promoted by DBDPE at ≤ 5 mg/L and inhibited at > 5 mg/L with 96-h exposure. MDA (malondialdehyde) content rose obviously with DBDPE exposure (10-50 mg/L). The mycelium was wizened under 20 mg/L DBDPE exposure according to SEM observation. Transcriptomics analysis suggested that DBDPE could change many functional genes expression of P. ostreatus. GO analysis indicated DBDPE could affect biological process and cellular component by inhibiting electron transport, mitochondrial ATP synthesis, oxidoreductase activity as well as transporter activity. KEGG enrichment pathways analysis indicated DBDPE could inhibit oxidative phosphorylation, tricarboxylic acid (TCA) cycle and carbon metabolism by down-regulating the genes related to NADH reductase/dehydrogenase, succinate dehydrogenase, cytochrome-c reductase/oxidase, cytochrome C1 protein and ATP synthase.

Assessment of exposure to perfluoroalkyl substances (PFASs) in dogs by fur analysis

Poly- and perfluoroalkyl substances (PFASs) are a large group of chemicals commonly used in various branches of industry, which may adversely affect the living organisms. The aim of this study were to evaluate exposure of dogs to six selected PFASs: five perfluoroalkyl carboxylic acids (perfluorobutanoic acid - PFBuA, perfluoropentanoic acid - PFPeA, perfluorohexanoic acid - PFHxA, perfluoroheptanoic acid - PFHpA, perfluorooctanoic acid - PFOA) and perfluorooctane sulfonic acid (PFOS) through the analysis of fur samples. To our knowledge this is the first study concerning the use of fur samples to evaluation of exposure of domestic animals to PFASs. Relationship between PFASs concentration and age, gender and body weight of animals was also evaluated. Fur samples were collected from 30 dogs living in Olsztyn (Poland). All PFASs studied were detected in the canine fur samples. The highest concentrations were observed in the case of PFOA and PFBuA, detected at concentrations in the range between 1.51 and 66.7 ng/g and 0.98-26.6 ng/g, respectively. During the present study generally no statistically significant differences dependent on gender, age and body weight of animals were found. This study confirms the suitability of fur samples for biomonitoring of exposure to PFASs in domestic animals, what may be important in veterinary toxicology.

Concentrations of organic contaminants in industrial and municipal bioresources recycled in agriculture in the UK

Many types of bioresource materials are beneficially recycled in agriculture for soil improvement and as alternative bedding materials for livestock, but they also potentially transfer contaminants into plant and animal foods. Representative types of industrial and municipal bioresources were selected to assess the extent of organic chemical contamination, including: (i) land applied materials: treated sewage sludge (biosolids), meat and bone meal ash (MBMA), poultry litter ash (PLA), paper sludge ash (PSA) and compost-like-output (CLO), and (ii) bedding materials: recycled waste wood (RWW), dried paper sludge (DPS), paper sludge ash (PSA) and shredded cardboard. The materials generally contained lower concentrations of polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) relative to earlier reports, indicating the decline in environmental emissions of these established contaminants. However, concentrations of polycyclic aromatic hydrocarbons (PAHs) remain elevated in biosolids samples from urban catchments. Polybrominated dibenzo-p-dioxins/dibenzofurans (PBDD/Fs) were present in larger amounts in biosolids and CLO compared to their chlorinated counterparts and hence are of potentially greater significance in contemporary materials. The presence of non-ortho-polychlorinated biphenyls (PCBs) in DPS was probably due to non-legacy sources of PCBs in paper production. Flame retardent chemicals were one of the most significant and extensive groups of contaminants found in the bioresource materials. Decabromodiphenylether (deca-BDE) was the most abundant polybrominated diphenyl ether (PBDE) and may explain the formation and high concentrations of PBDD/Fs detected. Emerging flame retardant compounds, including: decabromodiphenylethane (DBDPE) and organophosphate flame retardants (OPFRs), were also detected in several of the materials. The profile of perfluoroalkyl substances (PFAS) depended on the type of waste category; perfluoroundecanoic acid (PFUnDA) was the most significant PFAS for DPS, whereas perfluorooctane sulfonate (PFOS) was dominant in biosolids and CLO. The concentrations of polychlorinated alkanes (PCAs) and di-2-ethylhexyl phthalate (DEHP) were generally much larger than the other contaminants measured, indicating that there are major anthropogenic sources of these potentially hazardous chemicals entering the environment. The study results suggest that continued vigilance is required to control emissions and sources of these contaminants to support the beneficial use of secondary bioresource materials.

Different transport behaviors and mechanisms of perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in saturated porous media

Perfluorooctanoate (PFOA) and perfluorooctane sulfonate (PFOS) in soil aroused increasing concern, however there is little information about their transport in porous media, which is urgently needed to better control their environmental risks. In this study, saturated sand columns (considering the coupled effect of solution cation type and pH) and a two-site nonequilibrium transport model (TSM) were used to investigate the transport behaviors and mechanisms of PFOA and PFOS. Breakthrough data and the TSM parameters showed PFOA had higher mobility than PFOS, and divalent cation could inhibit their transport by increasing the nonequilibrium interactions between them and the sand. pH had little influence on PFOA migration when there was only monovalent cation in the solution since PFOA had limited affinity with the sand, however, polyvalent cation could provide additional adsorption sites for it through cation bridging and enhance the effect of pH. Differently, decreasing pH inhibited the transport of PFOS more significantly, and the effect was stronger than that of changing cation type. That proved mechanisms like hydrogen-bonding which were sensitive to solution pH played an important role in PFOS migration. These results provide important scientific basis to the remediation strategy and the migration prediction model development of PFOA and PFOS.

Simultaneous reduction of antibiotics and antibiotic resistance genes in pig manure using a composting process with a novel microbial agent

In recent years, in order to promote animal growth and reduce the risk of disease, a variety of antibiotics are frequently added to the animal feed of livestock and poultry. However, these antibiotics can not be fully digested by animals and most of them are excreted with feces, consequently causing the enrichment of antibiotic resistance genes (ARGs) and huge environmental risks. Nowadays, composting is a better option to solve these problems. Accordingly, this study explored the effects of co-composting swine manure with different inoculants dominated by Phanerochaete chrysosporium (p), Aspergillus niger (a), and Bacillus licheniformis (b) on the simultaneous removal of multiple antibiotics and resistance genes and evolution of the bacterial community. The results showed that the highest removal extent of tetracycline and oxytetracycline occurred in pile D (p:b:a=1:5:5, biomass) reaching 89.2% and 87.8%, respectively, while the highest removal extent of doxycycline and enrofloxacin occurred in pile A (p:b:a=1:0:0, biomass) reaching 98.6% and 89%, respectively. Compared with the levels in pile B (control check), in pile D, ARGs, except those for sulfonamides, decreased by 1.059 × 10^-3-6.68 × 10^-2 gene copies/16S rRNA copies. Inoculation with p alone effectively reduced intI1 and intI2. Canonical correspondence analysis (CCA) that microbial community structure evolution had a greater influence on ARGs than environmental factors. In summary, this study provided a feasible way to efficiently remove the antibiotics and antibiotic resistance genes in pig manure.

Uptake, translocation and toxicity of chlorinated polyfluoroalkyl ether potassium sulfonate (F53B) and chromium co-contamination in water spinach (Ipomoea aquatica Forsk)

Bioaccumulation and toxicity of per-and polyfluoroalkyl substances and metal in plants have been confirmed, however their contamination in soil and plants still requires extensive investigation. In this study the combined effects of chlorinated polyfluoroalkyl ether potassium sulfonate (F53B) and chromium (Cr) on water spinach (Ipomoea aquatica Forsk) were investigated. Compared with each single stress, the combination of F53B and Cr (VI) reduced the biomass and height and increasingly accumulated in the roots and destroyed the cell structure. Besides, the co-contamination led to the immobilization of F53B and Cr (VI) in soil, which affected their migration in soil and transfer to plants. The antioxidant response and photosynthesis of the plant weakened under the single Cr (VI) and enhanced under the single F53B treatment; however the contamination of F53B and Cr (VI) could also reduce this effect, as confirmed by the gene expression of MTa, psbA and psbcL genes. This study provides an evidence of the environmental risks resulting from the coexistence of F53B and Cr (VI).

New application of rutin: Repair the toxicity of emerging perfluoroalkyl substance to Pseudomonas stutzeri

Per- and polyfluoroalkyl substances (PFASs) are toxic to microorganisms, thereby affecting microbial communities in sludge and soil, but how to repair the toxicity of microorganisms remains unclear. In this study, rutin, an antioxidant, was added into a culture medium with an aerobic denitrification bacteria, Pseudomonas stutzeri, under the exposure of sodium perfluorononyloxy-benzenesulfonate (OBS) to evaluate the repair mechanisms of rutin to the toxicity of OBS to the bacteria. The results showed that rutin could repair the damage of OBS to cell structures, and reduce the death rates of the bacteria under OBS exposure. The dosage of rutin reduced the effect on the inhibition of denitrification ability of P. stutzeri under OBS exposure. Compared with the bacteria exposed to single OBS, the dosage of rutin resulted in that the death rates recovered from 96.2% to 66.4%, the growth inhibition rate decreased from 46.5% to 15.8%, the total nitrogen removal rate recovered from 66.9% to 100%, and the NO₂^- content recovered from 34.5 mg/L to 0.22 mg/L. The expressions of key denitrification genes (napA, nirS, norB, nosZ) were recovered after adding rutin under OBS exposure. Rutin changed the positive rate of reactive oxygen species, the relative superoxide dismutase and catalase activities in the bacteria which exposed to OBS. The mechanism by which rutin repaired the toxicity of OBS to P. stutzeri related to inhibiting the activities of antioxidant and denitrification enzymes rather than affecting the expressions of genes involved in these enzymes. This study sheds light on the repair method of micro-organics and reveals the repair mechanisms under PFASs exposure.

Toxic effect of perfluorooctane sulfonate on plants in vertical-flow constructed wetlands

Per-and polyfluoroalkyl substances (PFASs) can be taken up and bioaccumulated in plants, but the toxic mechanisms of PFASs on wetland plants are still unclear. In present study, the toxic influences of perfluorooctane sulfonate (PFOS) on Eichhornia crassipes (E. crassipes) and Cyperus alternifolius (C. alternifolius) in a vertical-subsurface-flow constructed wetland were evaluated. The results showed that E. crassipes was more tolerant to PFOS stress than C. alternifolius, and the growth and chlorophyll synthesis of the two plants were promoted by low concentration (<0.1 mg/L) of PFOS, and the chlorophyll synthesis was inhibited by high concentration (10 mg/L) of PFOS but the growth did not change obviously. The catalase activity and malondialdehyde content in the leaves of the two plants increased, peroxidase activity decreased under exposure to high concentrations of PFOS, and superoxide dismutase activity did not change. Under PFOS stress, the membrane of plant leaves and the cell structure of the two wetland plants were destroyed, and the mitochondrial contour of root cells became incomplete. Tanscriptomic analysis showed that the expression levels of genes related to cell wall formation, the cell apoptosis pathway, material synthesis, and metabolism in the plants were changed by PFOS. Analysis in fluorogenic quantitative real time polymerase chain reaction (RT-qPCR) also confirmed that the photosynthesis system of E. crassipes was inhibited, while that of C. alternifolius was promoted.

Perfluoro-octanoic acid impairs sperm motility through the alteration of plasma membrane

CONTEXT

Perfluoroalkyl-substances (PFAS) are chemical additives considered harmful for humans. We recently showed that accumulation of perfluoro-octanoic acid (PFOA) in human semen of exposed subjects was associated with altered motility parameters of sperm cells, suggesting direct toxicity.

OBJECTIVES

To determine whether direct exposure of human spermatozoa to PFOA was associated to impairment of cell function.

PATIENTS AND METHODS

Spermatozoa isolated from semen samples of ten normozoospermic healthy donors were exposed up to 2 h to PFOA, at concentrations from 0.1 to 10 ng/mL. Viability and motility parameters were evaluated by Sperm Class Analyser. Cell respiratory function was assessed by both mitochondrial probe JC-1 and respiratory control ratio (RCR) determination. Sperm accumulation of PFOA was quantified by liquid chromatography-mass spectrometry. Expression of organic ion-transporters OATP1 and SLCO1B2 was assessed by immunofluorescence and respective role in PFOA accumulation was evaluated by either blockade with probenecid or membrane scavenging through β-cyclodextrin (β-CD). Plasma membrane fluidity and electrochemical potential (ΔΨp) were evaluated, respectively, with Merocyanine-540 and Di-3-ANEPPDHQ fluorescent probes.

RESULTS

Compared to untreated controls, a threefold increase of the percentage of non-motile sperms was observed after 2 h of exposure to PFOA regardless of the concentration of PFOA, whilst RCR was significantly reduced. Only scavenging with β-CD was effective in reducing PFOA accumulation, suggesting membrane involvement. Altered membrane fluidity, reduced ΔΨp and sperm motility loss associated with exposure to PFOA were reverted by β-CD treatment.

CONCLUSION

PFOA alters human sperm motility through plasma-membrane disruption, an effect recovered by incubation with β-CD.

iTRAQ-Based Comparative Proteomic Analysis of Acinetobacter baylyi ADP1 Under DNA Damage in Relation to Different Carbon Sources

DNA damage response allows microorganisms to repair or bypass DNA damage and maintain the genome integrity. It has attracted increasing attention but the underlying influential factors affecting DNA damage response are still unclear. In this work, isobaric tags for relative and absolute quantification (iTRAQ)-based proteomic analysis was used to investigate the influence of carbon sources on the translational response of Acinetobacter baylyi ADP1 to DNA damage. After cultivating in a nutrient-rich medium (LB) and defined media supplemented with four different carbon sources (acetate, citrate, pyruvate, and succinate), a total of 2807 proteins were identified. Among them, 84 proteins involved in stress response were significantly altered, indicating the strong influence of carbon source on the response of A. baylyi ADP1 to DNA damage and other stresses. As the first study on the comparative global proteomic changes in A. baylyi ADP1 under DNA damage across nutritional environments, our findings revealed that DNA damage response in A. baylyi ADP1 at the translational level is significantly altered by carbon source, providing an insight into the complex protein interactions across carbon sources and offering theoretical clues for further study to elucidate their general regulatory mechanism to adapt to different nutrient environments.

Black rice anthocyanins embedded in self-assembled chitosan/chondroitin sulfate nanoparticles enhance apoptosis in HCT-116 cells

Self-assembled nanoparticles using the biopolymers chitosan (CH) and chondroitin sulfate (CS) were developed to improve the biological activity of anthocyanin (ACN). The 86.32 ± 0.15% (w/w) of ACN was incorporated into ACN/CH/CS nanoparticles, with the particle size of 350.1 ± 0.99 nm in diameter (i.d.) and 42.55 ± 0.54 in zeta potential (mV). Morphological study and thermogravimetric analysis suggested that the ACN/CH/CS nanoparticles exhibited heterogeneous morphology and high thermal stability. Significant increases in apoptosis by 12.1% and 35.1% were observed with 0.05 mg/ml ACN and ACN/CH/CS nanoparticles in the HCT-116 cell line, indicating that the nanoparticle system led to significant increase in apoptosis (p < 0.05). Structural changes in mitochondria caused by ACN/CH/CS nanoparticles indicated that the nanoparticles had negative impacts on mitochondria. These results showed that nanoparticles could potentially be used as a carrier system to improve the efficacy of ACN.