Comamonas endophytica sp. nov., a novel indole acetic acid producing endophyte isolated from bamboo in China.

Two novel indole acetic acid-producing strains, 5MLIRT and D4N7, were isolated from Indosasa shibataeoides in Yongzhou, Hunan province, and Phyllostachys edulis in Hangzhou, Zhejiang province, respectively. Based on their 16S rRNA sequences, strains 5MLIRT and D4N7 were closely related to Comamonas antarcticus 16-35-5T (98.4 % sequence similarity), and the results of 92-core gene phylogenetic trees showed that strains 5MLIRT and D4N7 formed a phylogenetic lineage within the clade comprising Comamonas species. The complete genome size of strain 5MLIRT was 4.49 Mb including two plasmids, and the DNA G+C content was 66.5 mol%. The draft genome of strain D4N7 was 4.26 Mb with 66.7 mol% G+C content. The average nucleotide identity and digital DNA-DNA hybridization values among strain 5MLIRT and species in the genus Comamonas were all below the species delineation threshold. The colonies of strain 5MLIRT and D4N7 were circular with regular margins, convex, pale yellow and 1.0-2.0 mm in diameter when incubated at 30 °C for 3 days. Strains 5MLIRT and D4N7 grew optimally at 30 °C, pH 7.0 and 1.0 % NaCl. The respiratory isoprenoid quinone was ubiquinone-8. The major polar lipids were phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Polyphasic analyses indicated that strains 5MLIRT and D4N7 could be distinguished from related validly named Comamonas species and represent a novel species of the genus Comamonas, for which the name Comamonas endophytica sp. nov. is proposed. The type strain is 5MLIRT (=ACCC 62069T=GDMCC 1.2958T=JCM 35331T).

In-situ synthesis of biochar modified PbMoO4: An efficient visible light-driven photocatalyst for tetracycline removal.

For highly efficient photocatalytic remediation of organic pollutants, broad-spectrum light response and effective charge separation are two key goals. To achieve these goals, a novel biochar (BC) modified PbMoO4 composite catalyst was successfully synthesized in situ by combining coprecipitation with pyrolysis treatment of poplar sawdust and the technical feasibility of degradation of tetracycline (TC) with compound photocatalyst prepared from recovered agricultural and forestry residues was preliminarily demonstrated. The characterization demonstrated that the presence of BC narrowed the bandgap, enhanced visible light absorption as well as facilitated charge separation. Three composites (with the mass ratio of PbMoO4 to BC = 1:4; 1:1; and 4:1, respectively) displayed higher activity than pure PbMoO4. The results showed that the composite with the PbMoO4 to BC ratio of 1:4 exhibited the best photocatalytic activity, for 150 mg L-1 TC the removal rate was 61.0%, and the rate constant was 8.1 × 10-3 min-1, while the photocatalytic activity of PbMoO4 was 26.0% and 3.9 × 10-3 min-1. The reactions in the presence of radical quenchers indicated that holes (h+) and superoxide radicals (O2-) were the dominant active species for photodegradation. In different water matrices, for 150 mg L-1 TC solution the photocatalytic activity of optimal photocatalyst decreased as follows: ultrapure water > artificial sewage > farm sewage > municipal sewage. Moreover, the catalyst exhibited good stability over five cycles. Therefore, BC doped PbMoO4 provides a useful strategy for improving the photocatalytic ability of PbMoO4-based photocatalysts and offers a promising method for water purification.

Enhanced Removal of Antibiotic in Wastewater Using Liquid Nitrogen-Treated Carbon Material: Material Properties and Removal Mechanisms.

Antibiotic residues in the aquatic environment have become a global problem posing a serious threat to the environment and an inherent health risk to human beings. In this study, experiments were carried to investigate the use of carbon material modified by liquid nitrogen treatment (CM1) and carbon material unmodified by liquid nitrogen treatment (CM2) as adsorbents for the removal of the antibiotic ampicillin from aqueous solutions. The properties of the CMs (CM1 and CM2) and the effects of variations of the key operating parameters on the removal process were examined, and kinetic, isothermal and thermodynamic experimental data were studied. The results showed that CM1 had larger specific surface area and pore size than CM2. The ampicillin adsorption was more effective on CM1 than that on CM2, and the maximum adsorption capacity of ampicillin onto CM1 and CM2 was 206.002 and 178.423 mg/g, respectively. The kinetic data revealed that the pesudo-second order model was more suitable for the fitting of the experimental kinetic data and the isothermal data indicated that the Langmuir model was successfully correlated with the data. The adsorption of ampicillin was a spontaneous reaction dominated by thermodynamics. In synthetic wastewater, CM1 and CM2 showed different removal rates for ampicillin: 92.31% and 86.56%, respectively. For an adsorption-based approach, carbon material obtained by the liquid nitrogen treatment method has a stronger adsorption capacity, faster adsorption, and was non-toxic, therefore, it could be a promising adsorbent, with promising prospects in environmental pollution remediation applications.

[Curcumin inhibits hypoxia-induced proliferation of MRC-5 and collagen I synthesis].

OBJECTIVE: To investigate the effect of curcumin on MRC-5 in human embryo fibroblast (HEF) under hypoxia and possible underlying mechanism. METHODS: The MRC-5 were cultured in vivo under 5 different conditions, including normal control, SB203580 (10 micromol/L), LY-294002 (10 micromol/L) and curcumin (5,10 and 20 micromol/L, respectively). The proliferation of MRC-5 was assessed by MTT assay and the expressions of pro-collal, p-p38 and p-AKT were detected by western blot. RESULTS: Compared with the nomoxia control, hypoxia enhanced the proliferation of MRC-5 and the expressions of pro-collal, p-p38 and p-AKT (P < 0.05). Curcumin inhibited the hypoxia-induced proliferation of MRC and the expression of pro-collal and p-p38 (P < 0.05), but not the expression of p-AKT (P > 0.05). CONCLUSION: Hypoxia might enhance the proliferation of MRC-5 cells and the expression of collagen I through PI3K/AKT and p38MAPK. Curcumin blocks the hypoxia influence through is impact on p38MAPK.

[The effect of hypoxia on the expression of RHO/RHO signaling pathway and CTGF of human embryonic fibroblasts].

OBJECTIVE: To observe the effects of hypoxia on cell proliferation and the expression of RHO/RHO signaling pathway, connective tissue growth factor (CTGF) and the collagen type I (Col I) in human embryonic fibroblasts at different time points, and study the possible mechanism of hypoxia-induced pulmonary fibrosis. METHODS: Human embryonic fibroblasts were cultured under hypoxic condition (37 degrees C, 5 CO2, 2% O2, 93% N2) for 0 h, 1.5 h, 3 h, 6 h, 12 h, 24 h, 48 h and 60 h respectively. The protein levels of HIF-1alpha, RhoA, ROCKland CTGF were assayed by Western blot. RT-PCR was performed to detect the mRNA levels of HIF-1alpha, ROCK1, CTGF and Col I. The concentration of collagen type I (Col I) in fibroblast cells supernatant were determined by ELISA. RESULTS: (1) Basal levels of RhoA, ROCK1, CTGF protein of MRC-5 were observed in normoxia, but the protein levels of RhoA, ROCK1 and CTGF were up-regulated after 1.5 h of hypoxia and increased further with longer exposure to hypoxia. It also demonstrated significant positive correlation between the protein levels of RhoA, ROCK1 and CTGF at different time points of hypoxia. (2) After 1.5 h, mRNA expression of ROCK1, CTGF and Col I was elevated and increased further with longer exposure to hypoxia and peaked after 60 h of hypoxia compared to normoxia. (3) Compared with normoxia, the concentration of Col I in fibroblast cells supernatant increased in different time points of hypoxia and peaked after 24 h of hypoxia. CONCLUSION: Different time points of hypoxia all significantly up-regulated the expression of protein and mRNA of CTGF and increased the secretion of Col I. Hypoxia could represent a potential brotic stimulus possibly through activation of the RHO/RHO signaling pathway, up-regulating the expression of HIF-1alpha and CTGF, triggering a series of brotic responses.