Reduction characteristic of chlorobenzene by a newly isolated Paenarthrobacter ureafaciens LY from a pharmaceutical wastewater treatment plant.

A highly efficient chlorobenzene-degrading strain was isolated from the sludge of a sewage treatment plant associated with a pharmaceutical company. The strain exhibited a similarity of over 99.9% with multiple strains of Paenarthrobacter ureafaciens. Therefore, the strain was suggested to be P. ureafaciens LY. This novel strain exhibited a broad spectrum of pollutant degradation capabilities, effectively degrading chlorobenzene and other organic pollutants, such as 1, 2, 4-trichlorobenzene, phenol, and xylene. Moreover, P. ureafaciens LY co-metabolized mixtures of chlorobenzene with 1, 2, 4-trichlorobenzene or phenol. Evaluation of its degradation efficiency showed that it achieved an impressive degradation rate of 94.78% for chlorobenzene within 8 h. The Haldane-Andrews model was used to describe the growth of P. ureafaciens LY under specific pollutants and its concentrations, revealing a maximum specific growth rate (µmax ) of 0.33 h-1 . The isolation and characterization of P. ureafaciens LY, along with its ability to degrade chlorobenzene, provides valuable insights for the development of efficient and eco-friendly approaches to mitigate chlorobenzene contamination. Additionally, investigation of the degradation performance of the strain in the presence of other pollutants offers important information for understanding the complexities of co-metabolism in mixed-pollutant environments.

Performance and Microbial Community Analysis of an Electrobiofilm Reactor Enhanced by Ferrous-EDTA.

The biological reduction of ferrous ethylenediaminetetraacetic acid (EDTA-FeII-NO and EDTA-FeIII) is an important process in the integrated electrobiofilm reduction method, and it has been regarded as a promising alternative method for removing NO x from industrial boiler flue gas. EDTA-FeII-NO and EDTA-FeIII are crucial substrates that should be biologically reduced at a high rate. However, they inhibit the reduction processes of one another when these two substrates are presented together, which might limit further promotion of the integrated method. In this study, an integrated electrobiofilm reduction system with high reduction rates of EDTA-FeII-NO and EDTA-FeIII was developed. The dynamic changes of microbial communities in the electrobiofilms were mainly investigated to analyze the changes during the reduction of these two substrates under different conditions. The results showed that compared to the conventional chemical absorption-biological reduction system, the reduction system exhibited better performance in terms of resistance to substrate shock loading and high microbial diversities. High-throughput sequencing analysis showed that Alicycliphilus, Enterobacteriaceae, and Raoultella were the dominant genera (>25% each) during the process of EDTA-FeII-NO reduction. Chryseobacterium had the ability to endure the shock loading of EDTA-FeIII, and the relative abundance of Chryseobacterium under abnormal operation conditions was up to 30.82%. Ochrobactrum was the main bacteria for reducing nitrate by electrons and the relative abundance still exhibited 16.11% under shock loading. Furthermore, higher microbial diversity and stable reactor operation were achieved when the concentrations of EDTA-FeII-NO and EDTA-FeIII approached the same value (9 mmol·L-1).

[Effect of Human Umbilical Cord-derived Mesenchymal Stem Cells on Proliferation and Differentiation of Leukemia Cells].

OBJECTIVE: To investigate the effect of human umbilical cord-derived mesenchymal stem cells(HUC-MSC) on the proliferation and differentiation of NB4 treated with all-trans retinoid acid (ATRA) and its underlining mechanisms . METHODS: Human umbilical cord mesenchymal stem cells were isolated from umbilical cord of newborns. Co-culture system was established by HUC-MSC and NB4 in vitro. The experiment was divided into 4 groups: NB4 group (NB4 cells alone) , NM group (NB4 cells co-cultured with HUC-MSC) , NA group (NB4 cells treated with ATRA) , NMA group (NB4 cells co-cultured with HUC-MSC and treated with ATRA) . NB4 cells were counted by a microscopy, NB4 proliferation was monitored by CCK-8 assay, NB4 differentiation was assessed by Wright ' s staining and nitroblue tetrazolium reduction test. IL-6 levels in the culture supernatant of different groups were tested by ELISA kit. Quantitative PCR was used to detect the transcription level of CDKN1A, CCND1 and Survivin. RESULTS: NB4 and HUC-MSC in the co-culturing systems were in good condition with a slight repression of NB4 proliferation by HUC-MSC. HUC-MSC could collaborate with ATRA to induce significant NB4 differentiation. Consistent with this finding, IL-6 expression levels of co-cultured groups were remarkably higher than that in any other groups or the group of HUC-MSC alone. The quantitative PCR analysis showed that the levels of CDKN1A and CCND1 mRNA expression were increased or decreased respectively in the co-cultured groups. CONCLUSION: HUC-MSC co-culture can reduce proliferation but promote the differentiation of NB4 cells, suggesting that this effect may be closely related with the secretion of IL-6 which can affect the expression of some factors in vitro.

Phase I evaluation of the safety and pharmacokinetics of a single-dose intravenous injection of a murine monoclonal antibody against Hantaan virus in healthy volunteers.

Anti-Hantaan virus monoclonal antibody (AHM) is a murine monoclonal antibody against Hantaan virus being developed for the treatment of hemorrhagic fever with renal syndrome. The purpose of the present study was to describe the tolerance and pharmacokinetics of an intravenously administered single ascending dose of AHM in Chinese healthy volunteers. Four cohorts of 22 healthy subjects received AHM at 2.5 to 20 mg, and the results indicated that AHM was well tolerated. We established a highly sensitive, rapid, and accurate immunoassay for the kinetic analysis of AHM in serum. Serial blood samples were obtained after intravenous administration for up to 17 days. A one-compartment model was determined to best describe the disposition of AHM. The maximal level in serum and the area under the serum concentration-time curve were proportional to the doses. The mean clearance, the half-life, and the volume of distribution were constant, irrespective of the dose. AHM was slowly cleared and had a half-life of approximately 110 h. These data support the use of a treatment regimen in which AHM is given only once intravenously.