Microplastics (MPs) are ubiquitous in the environment, can adsorb organic contaminants (OCs) and be taken by various microorganisms and organisms, which could eventually lead to risk to humans. In this study, the phenotypic changes and metabolic profile alternations of zebrafish in the single- and co-exposure of MPs and phenanthrene (Phe) were investigated. The results showed that significantly higher tail malformation rate and edema rate in zebrafish induced by MPs can be enhanced with the co-existence of Phe. The metabolomic analysis revealed that both synergistic and antagonistic effects of MPs and Phe on the metabolic alternation of zebrafish larvae exist, since unique perturbations of metabolites or pathways were found in all of the three exposure scenarios. Based on PLS-DA, porphine, ribose, and L-glutamic acid were the most important metabolites resulting in the difference between the treated and control groups in the MP exposure, Phe exposure and co-exposure, respectively. Two dysregulated pathways namely d-glutamine and D-glutamate metabolism, and alanine, aspartate and glutamate metabolism were significantly affected in the co-exposure while not in either of the single exposure. These findings provide new insights into the toxic effects of MPs on aquatic organisms, and further studies on combined effects of MPs and OCs are suggested to be conducted.

Pollutant degradation and heavy-metal resistance may be important features of the rhizobia, making them promising agents for environment cleanup biotechnology. The degradation of phenanthrene, a three-ring polycyclic aromatic hydrocarbon (PAH), by the rhizobial strain Rsf11 isolated from the oil-polluted rhizosphere of alfalfa and the influence of nickel ions on this process were studied. On the basis of whole-genome and polyphasic taxonomy, the bacterium Rsf11 represent a novel species of the genus Neorhizobium, so the name Neorhizobium phenanthreniclasticum sp. nov. was proposed. Analysis of phenanthrene degradation by the Rsf1 strain revealed 1-hydroxy-2-naphthoic acid as the key intermediate and the activity of two enzymes apparently involved in PAH degradation. It was also shown that the nickel resistance of Rsf11 was connected with the extracellular adsorption of metal by EPS. The joint presence of phenanthrene and nickel in the medium reduced the degradation of PAH by the microorganism, apparently due to the inhibition of microbial growth but not due to the inhibition of the activity of the PAH degradation enzymes. Genes potentially involved in PAH catabolism and nickel resistance were discovered in the microorganism studied. N. phenanthreniclasticum strain Rsf11 can be considered as a promising candidate for use in the bioremediation of mixed PAH-heavy-metal contamination.

Polyaromatic hydrocarbons (PAHs) are widely spread pollutants in the environment, including soil and water. Anthracene (anth) and phenanthrene (phen) pose severe health impacts on human lives due to their carcinogenic nature by increasing cancer risk to the skin, lungs, and bladder. Fluorescence spectroscopy is a promising , efficient and straightforward tool for characterizing these trace PAHs in water. Therefore, the current work provides a detailed insight into the fluorescence properties of anth and phen in water. The fluorescence EEMs (excitation-emission matrices) of anth showed emissions at 380 nm, 400 nm, and 425 nm with single excitation at 250 nm, whereas phen showed two emissions < 380 nm, at 350 nm and 365 with single excitation at 250 nm. Then the theoretical EX/EM wavelengths were calculated by DFT and CIS-B3LYP for these compounds in water. The environmental effect of pH variation on fluorescence EEM shows a significant difference in fluorescence intensity without changing in peak locations, with highest fluorescence intensity at neutral pH than acidic and alkaline. Furthermore, the theoretical pH effect was described for the first time by simulating the protonated (+ 1), deprotonated (-1) and neutral molecules in water at the DFT level of theory. The variation in simulated oscillator strengths was similar in trend with the experimental fluorescence intensity of these compounds. The HOMO-LUMO were calculated to obtain the energy gap, molecular softness, molecular hardness, electronic potential and electrophilicity of anth and phen. To find the fluorophore contribution, the fluorescence of homogeneous mixture of both isomers was analyzed, which showed an enhanced fluorescence intensity of anth by 12-20%, whereas a decrease of 9-14% was observed in phen. This study describes that the fluorescence technique could be a fast and easy method to distinguish and identify PAHs isomers (anth and phen) in water.

The increasing use of biodegradable plastics may result in more serious pollution of microplastics which often coexist with biochar in soil, this will affect how organic pollutants move and transform in the soil. This work investigated the effect of biodegradable polybutylene adipate-co-terephthalate (PBAT) coexistence with biochars produced at temperatures of 400 and 700 °C (W4 and W7) on soil bacterial communities and phenanthrene degradation. The results showed that coexistence of PBAT and biochar paticles greatly boosted the relative abundance of Nocardioides while decreased the relative abundance of Sphingomonas as compared to soils with a single addition of PBAT or biochar. Changes in soil Eh values were the most influential factor in bacterial communities (more than 40% contribution). The degradation ratio of phenanthrene when PBAT coexisted with W7 (39.6 ± 3.6%) was not significantly different from the treatment with a single W7 addition (35.0 ± 2.3%, P＞0.05), and was related to phenanthrene degradation in the adsorbed state of W7 in soil. In contrast, the degradation ratio of phenanthrene in PBAT coexisting with W4 (35.1 ± 3.5%) was intermediate between that of single PBAT (49.8 ± 0.9%) and W4 (13.7 ± 5.8%) treatments. This was primarily due to changes in the experiment\'s initial bioavailable phenanthrene content. Furthermore, after the introduction of earthworms, phenanthrene degradation ratio in coexistence treatments were very similar to that described above in the absence of earthworms. Except for two treatments that contain W7, phenanthrene degradation ratio in the other treatments was increased by the presence of earthworms (up to 23%), which is related to the enhanced relative abundance of polycyclic aromatic hydrocarbon-degraders. Our findings indicated that PBAT coexistence with high-temperature or low-temperature biochar had a completely different impact on bacterial communities and phenanthrene degradation in soil.

Microplastics (MPs), an emerging pollutant, widely co-occur with polycyclic aromatic hydrocarbons (PAHs) in the environment. Therefore, the interaction between MPs and PAHs has been the focus of much attention in recent years. In this study, three types of MPs, i.e., polypropylene, polystyrene, and poly(vinyl chloride), with the same main chain were selected as the adsorbents, with phenanthrene (PHE) as the representative PAHs. The adsorption mechanisms were explored from the perspective of the molecular spectral level using a combination of Fourier transform infrared spectroscopy (FT-IR) with a two-dimensional correlation technique. The adsorption kinetics results showed that the adsorption of PHE on the three MPs was dominated by chemisorption. However, the FT-IR analysis results indicated that no new covalent bond was created during the adsorption process. Based on the above research, a generalized two-dimensional (2D) correlation spectral technique was employed to investigate the sequence of functional group changes during the adsorption process for different MPs. Furthermore, the hybrid 2D correlation spectral technique explored the effect of side groups attached to the main chain molecules of MPs on adsorption. The results showed that for all three MPs, the functional groups in the side chain have a higher affinity for PHE, which is due to their higher hydrophobicity. This study provides a feasible way to analyze the adsorption of pollutants on MPs, and the results are important for understanding the adsorption interaction between PAHs and MPs in the aquatic environment.

Soil composition varies considerably in nature, so it is vital to investigate the mechanism of the effect of various soil parameters on biochar sorption capacity. In this study, two biochars (W4 and W7) were derived from wheat straw at temperatures of 400 and 700 °C and were incubated with three different soils. Changes in biochar surface features by aging in the soils and the consequent impact on phenanthrene sorption were examined. The results showed that the effect of adding biochar on phenanthrene sorption capacity (Koc) varied by soil. When biochar was freshly mixed with soil, the Koc value in soil with higher clay content was more dramatically altered by biochar, which is due to clay particles adhering to the biochar surface. Moreover, the Koc value was significantly decreased by the addition of W4 but increased by the addition of W7 in general. After aging, most of the Koc value decreased. The greatest decrease in Koc value was observed in biochar and soil composed with the highest clay content for W4 (24-63%), as well as soil composed with the highest organic matter content for W7 (46-64%). This is because the surface polarity and micropores of biochar dropped the most rapidly in these mixes, resulting in a significant decrease in hydrophobic and pore-filling properties. The results revealed that the impact of biochar-soil interactions on phenanthrene sorption is related to not only biochar properties but also soil clay particles, soil organic matter content and pH. The findings of the study can be utilized to assess the efficacy of biochar application in soil remediation for various features.

UNASSIGNED: Phenanthrene, a polycyclic aromatic hydrocarbon, is found in abundance in environmental pollutants, food, and drinking water. This substance can accumulate in body tissues and exert harmful effects. Moreover, phenanthrene can cross the placental barrier, potentially impacting fetal development. We aimed to explore the impacts of maternal exposure to phenanthrene on testicular tissue and Sertoli cell function in F1 mice.
UNASSIGNED: Female rats with vaginal plugs were randomly assigned to one of three groups: control, sham, or phenanthrene. The control group received no intervention during pregnancy. In the sham and phenanthrene groups, corn oil and a phenanthrene solution, respectively, were administered via gavage once every 2 days. Offspring were separated by sex 21 days after birth. At 56 days postnatal, male F1 offspring were euthanized, and their testes were harvested for histological and molecular analyses.
UNASSIGNED: Phenanthrene exposure was associated with a lower testicular weight and volume, a smaller diameter of the seminiferous tubules, and a relative thinning of the germinal epithelium. These changes were associated with increased cellular apoptosis, as shown by the upregulation of caspase 3 expression. Additionally, we observed an increase in vacuolization and residual bodies within the tissue. Conversely, the number of Sertoli cells and expression levels of Sox9, as well as the Ocln and Itgb1 genes, were found to be lowered.
UNASSIGNED: Maternal exposure to phenanthrene impacts both germ cells and Sertoli cells, disrupting their function and leading to fertility disorders in male F1 offspring mice.

Iron-rich constructed wetlands (CWs) could promote phenanthrene bioremediation efficiently through biotic and abiotic pathways, which have gained increasing attention. However, the biotic/abiotic transformation mechanisms of trace organic contaminants in iron-rich CW are still ambiguous. Herein, three CWs (i.e., CW-A: Control; CW-B: Iron-rich CW, CW-C: Iron-rich CW + tidal flow) were constructed to investigate the transformation mechanisms of phenanthrene through Mössbauer spectroscopy and metagenomics. Results demonstrated CW-C achieved the highest phenanthrene removal (94.0 %) and bacterial toxicity reduction (92.1 %) due to the optimized degradation pathway, and subsequently achieved the safe transformation of phenanthrene. Surface-bound/low-crystalline iron regulated hydroxyl radical (·OH) production predominantly, and its utilization was promoted in CW-C, which also improved electron transfer capacity. The enhanced electron transfer capacity led to the enrichment of PAH-degrading microorganisms (e.g., Thauera) and keystone species (Sphingobacteriales bacterium 46-32) in CW-C. Additionally, the abundances of phenanthrene transformation (e.g., EC:1.14.12.-) and tricarboxylic-acid-cycle (e.g., EC:2.3.3.1) enzyme were up-regulated in CW-C. Further analysis indicated that the safe transformation of phenanthrene was mainly attributed to the combined effect of abiotic (·OH and surface-bound/low-crystalline iron) and biotic (microbial community and diversity) mechanisms in CW-C, which contributed similarly. Our study revealed the essential role of active iron in the safe transformation of phenanthrene, and was beneficial for enhanced performance of iron-rich CW.

Chemical investigation on the aqueous extract of Dendrobium aphyllum led to the isolation of thirty-one constituents with structures identified by analysis of the extensive spectroscopic data (1D/2D NMR, MS, UV, and ECD), including previously undescribed two bibenzyls, one furfural, and one phenolic acid, namely trigonopol D (1), trigonopol C (2), dendrofunan A (10), and 6-(4-hydroxy-3-methoxyphenyl)-3,6-dioxohexyl acetate (30), respectively, as well as twenty-seven known ones. Among them, there were one new natural product (11), seven compounds (6-7, 9, 12, 20, 28, 31) described from the genus Dendrobium for the first time, and fifteen compounds (8, 13-17, 19, 21-27, 29) isolated from D. aphyllum for the first time. Further, the antioxidant and anti-inflammatory potentials of fifteen compounds (4-5, 8, 11-12, 14-19, 22, 24, 26, and 29) with significant scavenging capacities against DPPH and hydroxyl radicals, and virtual docking activities inhibiting COX-2 and 5-LOX, respectively. Our study may draw the attention of medicinal plant taxonomists and supply potential quality markers for discrimination of D. aphyllum from other species in Dendrobium genus.

Polycyclic aromatic hydrocarbons (PAHs) form an important group of organic pollutants due to their distribution in the environment and their carcinogenic and/or mutagenic effects. In order to identify at the molecular level some of the players in the biodegradation and tolerance response to PAHs in plants, we have phenotyped 32 Arabidopsis thaliana T-DNA mutant lines corresponding to 16 cytochrome P450 (CYP) genes that showed to be differentially expressed under contrasted stress conditions induced by phenanthrene, a 3-ring PAH. This screening has allowed us to identify CYP75B1 (At5g07990) T-DNA mutants as the only ones being sensitive to phenanthrene-induced stress, supporting that CYP75B1 protein is necessary for PAH tolerance. CYP75B1 codes for a 3\'flavonol hydroxylase. CYP75B1 gene was heterologously expressed on yeast in order to investigate whether it affects the A. thaliana response to phenanthrene by participating in its metabolization. Heterologously-produced CYP75B1 enzyme shows to be catalytically efficient against its physiological substrates (e.g., naringenin) but unable to metabolize phenanthrene or 9-phenanthrenol. In contrast, CYP75B1 seems rather involved in phenanthrene tolerance as a crucial element by regulating concentration of antioxidants through the production of 3\'-hydroxylated flavonoids such as quercetin and cyanidin. In particular, we report a highly increased generation of reactive oxygen species (H2O2 and singlet oxygen) in cyp75b1 mutants compared to control plants in response to phenanthrene treatment. Overall, CYP75B1 shows to play an important role in the response to the deleterious effects of phenanthrene exposure and this is related to oxidative stress sensitivity rather than metabolization.