Impact of SRT on the efficiency and microbial community of sequential anaerobic and aerobic membrane bioreactors for the treatment of textile industry wastewater

The aim of this study is to evaluate the impact of SRT (infinite, 60 and 30 days) on the treatment and filtration characteristics of sequential anaerobic sulfate-reducing and aerobic sulfide-oxidizing MBRs treating textile wastewater. The influent COD, dye and sulfate concentrations were kept constant at 2000, 200 and 1000 mg/L, respectively. The decreased SRT caused substantial and partial decreases in COD oxidation and sulfate reduction, respectively, due to decrease of biomass concentration. Complete color removal was observed in the AnMBR and a slight increase in color was detected in the AeMBR. Sludge filterabilities were assessed with specific resistance to filtration, capillary suction time, and supernatant filterability tests. Compact and non-porous cake layer formed in the AnMBR. Metal-sulfide and Ca-P were detected in the cake layers of AnMBR and AeMBR, respectively, by SEM-EDS analyses. Desulfiiromonas thiophila and Thioalkalivibrio sulfidiphilus were dominant sulfate-reducing and sulfide oxidizing bacteria in AnMBR and AeMBR, respectively. (C) 2016 Elsevier B.V. All rights reserved

Using Bcl-xL anti-apoptotic protein for altering target cell apoptosis

WOS: 000314273600006Background: Altering target cell apoptosis is one of the challenging ideas of biotechnological applications. There are several applications of over expressing Bcl-xL anti-apoptotic protein from recombinant protein production to DNA vaccination strategies. The aim of the present study is to evaluate the anti-apoptotic efficacy of Bcl-xL expressing dual promoter plasmid system as a candidate to be used for recombinant protein production and DNA vaccination approaches. For this purpose, Bcl-xL anti-apoptotic protein gene was inserted in a dual expressing vector system in frame with EGFP (enhanced green fluorescence protein) after IRES (internal ribosomal site). The plasmid has a multiple cloning site after CMV (cytomegalovirus promoter) left empty to be inserted a biopharmaceutical protein gene region or DNA vaccine antigens. Results: In order to determine the anti-apoptotic efficacy of Bcl-xL inserted dual expressing vector, BHK-21 cells were transfected both with this plasmid and empty vector as control. Apoptosis was stimulated by several apoptosis inducing agents and serum deprivation in the transfected cells for 48 hrs. Cells expressing Bcl-xL protein in frame with EGFP were determined by flow cytometry as an indicator of cell viability. Additionally, apoptosis were determined by intracellular cleaved Casp 3 staining in Bcl-xL expressing EGFP positive cells. The dual expression plasmid bearing Bcl-xL anti-apoptotic protein prolonged the cell survival rate and protected cells from apoptosis upon apoptosis induction by doxorubicin and camptothecin in which the anti-apoptotic efficacies are inhibited through over expressing of Bcl-xL. pIRES2EGFP/Bcl-xL transfected cell ratio was significantly higher compared to empty vector transfected cells (P < 0.001). In contrast, apoptotic cell ratio was significantly lower in pIRES2EGFP/Bcl-xL transfected cell population compared to empty vector transfected cells (P < 0.001). Conclusion: In conclusion, it was shown that in vitro transient expression of Bcl-xL efficiently inhibited apoptosis induced by serum deprivation, doxorubicin and camptothecin. Thus, the dual expression plasmid bearing Bcl-xL anti-apoptotic protein could be a good candidate for recombinant protein production and DNA vaccination applications.Scientific and Technological Research Council of Turkey (TUBITAK)Turkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [110O809]; Ege University, Science and Technology CenterEge University [2011BIL020]This work was partly funded by Scientific and Technological Research Council of Turkey (TUBITAK) by grant number 110O809 and Ege University, Science and Technology Center (2011BIL020)