Biotransformation of Organophosphate Esters by Rice and Rhizosphere Microbiome: Multiple Metabolic Pathways, Mechanism, and Toxicity Assessment.

The biotransformation behavior and toxicity of organophosphate esters (OPEs) in rice and rhizosphere microbiomes were comprehensively studied by hydroponic experiments. OPEs with lower hydrophobicity were liable to be translocated acropetally, and rhizosphere microbiome could reduce the uptake and translocation of OPEs in rice tissues. New metabolites were successfully identified in rice and rhizosphere microbiome, including hydrolysis, hydroxylated, methylated, and glutathione-, glucuronide-, and sulfate-conjugated products. Rhizobacteria and plants could cooperate to form a complex ecological interaction web for OPE elimination. Furthermore, active members of the rhizosphere microbiome during OPE degradation were revealed and the metagenomic analysis indicated that most of these active populations contained OPE-degrading genes. The results of metabolomics analyses for phytotoxicity assessment implied that several key function metabolic pathways of the rice plant were found perturbed by metabolites, such as diphenyl phosphate and monophenyl phosphate. In addition, the involved metabolism mechanisms, such as the carbohydrate metabolism, amino acid metabolism and synthesis, and nucleotide metabolism in Escherichia coli, were significantly altered after exposure to the products mixture of OPEs generated by rhizosphere microbiome. This work for the first time gives a comprehensive understanding of the entire metabolism of OPEs in plants and associated microbiome, and provides support for the ongoing risk assessment of emerging contaminants and, most critically, their transformation products.

Photocatalysis of carbamazepine via activating bisulfite by ultraviolet: Performance, transformation mechanism, and residual toxicity assessment of intermediates products.

Carbamazepine (CBZ) as an extensively distributed emerging pollutant has menaced ecological security. The degradation performance of CBZ by UV driven bisulfite process was investigated in this work. The kinetics results indicated that CBZ was high-efficiently degraded by UV/bisulfite following a pseudo first-order kinetic model (Kobs = 0.0925 min-1). SO4•- and •OH were verified as the reactive oxidants by EPR test and the radicals scavenging experiment using MeOH and TBA. SO4•- played a dominant role for CBZ degradation. The Density functional theory (DFT) and LC-qTOF-MS/MS clarified that hydroxylation, ketonation, ring opening reaction, and ring contraction were main transformation patterns of CBZ. As to influence factors, CBZ degradation was significantly hindered in presence of CO32-, HPO42- and NOM. Toxicological analysis derived from metabonomics suggested that the remarkable alteration of metabolic profile was triggered by exposure to intermediates mixture. CBZ intermediates interfered in several key metabolic pathways, including pentose phosphate, amino acids, lysine degradation, glycerophospholipid, glutathione, nucleotides and carbohydrate, which was alleviated after UV/bisulfite treatment. This work provided a meaningful support to potential risk of CBZ intermediates products, which shed light on the future application in eliminating drugs using UV /bisulfite.

Transformation of sulfamethoxazole by sulfidated nanoscale zerovalent iron activated persulfate: Mechanism and risk assessment using environmental metabolomics.

The threat caused by the misuse of antibiotics to ecology and human health has been aroused an extensive attention. Developing cost-effective techniques for removing antibiotics needs to put on the agenda. In current research, the degradation mechanism of sulfamethoxazole (SMX) by sulfidated nanoscale zerovalent iron (S-nZVI) driven persulfate, together with the potential risk of intermediates were studied. The degradation of SMX followed a pseudo-first order kinetics reaction with kobs at 0.1176 min-1. Both SO4•- and •OH were responsible for the degradation of SMX, and SO4•- was the predominant free radical. XPS analysis demonstrated that reduced sulfide species promoted the conversion of Fe (III) to Fe (II), resulting in the higher transformation rate of SMX. Six intermediates products were generated through hydroxylation, dehydration condensation, nucleophilic reaction, and hydrolysis. The risk of intermediates products is subsequently assessed using E. coli as a model microorganism. After E.coli exposure to intermediates for 24 h, the upmetabolism of carbohydrate, nucleotide, citrate acid cycle and downmetabolism of glutathione, sphingolipid, galactose by metabolomics analysis identified that SMX was effectively detoxified by oxidation treatment. These findings not only clarified the superiority of S-nZVI/persulfate, but also generated a novel insight into the security of advanced oxidation processes.

Biodegradation of decabromodiphenyl ether (BDE-209) using a novel microbial consortium GY1: Cells viability, pathway, toxicity assessment, and microbial function prediction.

GY1, a novel microbial consortium with efficient ability to degrade decabromodiphenyl ether (BDE-209) has been isolated and the sequencing analysis has been conducted. The results revealed that Hyphomicrobium, Pseudomonas, Aminobacter, Sphingopyxis, Chryseobacterium, Bacillus, Pseudaminobacter, Stenotrophomonas, Sphingobacterium and Microbacterium were the dominant genera, and the function genes involved in BDE-209 conversion were predicted by PICRUSt. When BDE-209 concentration increased from 0.5 to 10mg/L, its degradation efficiency declined from 57.2% to 22.3%. Various kinds of debrominated metabolites were detected during the biodegradation process, including BDE-208, BDE-207, BDE-206, BDE-205, BDE-190, BDE-181, BDE-155, BDE-154, BDE-99, BDE-47, BDE-17 and BDE-7. Also, the proportion of necrotic cells was observed during GY1 mediated degradation of BDE-209 to reveal the changes of cells viability under BDE-209 stress. Subsequent analysis showed that the reaction of BDE-209 with GY1 was a detoxification process and bioaugmentation with GY1 effectively enhanced BDE-209 degradation in actual water and water-sediment system.

[Dietary exposure assessment of antimony to inhabitants around mine contaminated areas in Nandan County in 2013-2014].

OBJECTIVE: To investigate the contents of antimony in Nandan food, and to research the effects of dietary pathways that mining surrounding usual's heavy metal intake due to mining activities. METHODS: Based on the data from weighing method and chemical analysis method, the dietary exposure level of antimony in Nandan was calculated, and the safety of antimony intake was evaluated by the TDI established by WHO. RESULTS: A total of 864 samples from 14 food categories were analyzed. The total detection rate was 97. 2%. And antimony concentrations in food ranged from not detected to 1. 750 µg/g, with median and geometric means of 0. 007 and 0. 008 µg/g, respectively. Dietary intakes of Sb by inhabitants in Nandan were below the TDI. The mainresource of antimony was meat which contributed 64. 4% and 61. 2% of the exposure. Antimony exposure to the human health risk assessmentresult show that, through diet of antimony intake, it would not cause obvious health risk to the local resident. However, the mining residents higher than the contrast areas residents, and male are apparently higher than those in female. CONCLUSION: The dietary of Sb exposure level was safe in general. However, the meat had a high risk to the residents.

Molecular Selection, Modification and Development of Therapeutic Oligonucleotide Aptamers.

Monoclonal antibodies are the dominant agents used in inhibition of biological target molecules for disease therapeutics, but there are concerns of immunogenicity, production, cost and stability. Oligonucleotide aptamers have comparable affinity and specificity to targets with monoclonal antibodies whilst they have minimal immunogenicity, high production, low cost and high stability, thus are promising inhibitors to rival antibodies for disease therapy. In this review, we will compare the detailed advantages and disadvantages of antibodies and aptamers in therapeutic applications and summarize recent progress in aptamer selection and modification approaches. We will present therapeutic oligonucleotide aptamers in preclinical studies for skeletal diseases and further discuss oligonucleotide aptamers in different stages of clinical evaluation for various disease therapies including macular degeneration, cancer, inflammation and coagulation to highlight the bright commercial future and potential challenges of therapeutic oligonucleotide aptamers.

[Analysis on layout of traditional Chinese medicine industry based on location quotient].

To observe the layout and evolution of the traditional Chinese medicine (TCM) medical industry, classify the industry by region and conduct a preliminary study on its professional advantages, competitiveness and possible cause by using the theory of location quotient in regional economics, in order to provide suggestions for the layout of the TCM medical industry.