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Xanthan is a biopolymer produced by Xanthomonas bacteria which is widely used in many industries such as food and oil. In this work, three Xanthomonas strains (X. citri/NIGEB-88, X. citri/NIGEB-386 and X. citri/NIGEB-K37) were used to evaluate their industrial potential to produce xanthan gum in whey medium. Bacteria growth rate, viscosity, biomass, dry weigh of produced xanthan and β-galactosidase activity were studied during the fermentation process and the presence of β-galactosidase genes was assessed by PCR technique. Strain NIGEB-386 had the best ability to utilize lactose in the whey medium. The highest amount of xanthan production and viscosity were 22.7 g/l and 2066.6 mPa·s, respectively. The presence of six β-galactosidase genes in strains NIGEB-386 and NIGEB-K37 was confirmed. The pyruvate and acetyl contents in xanthan gum were 2.1 and 0.29 %, respectively. Fourier-transform infrared spectroscopy analysis determined the position of the functional groups in the structure of the fermentation product. In whey medium, the performance of both NIGEB-386 and NIGEB-K37 strains were better than the X. campestris. The findings showed that Xanthomonas citri/NIGEB-386 is suitable for industrial production of xanthan using cheese whey as a low-cost medium.

Aims: In this research, the pro tective effects of this multicomponent vaccine were investigated using the BALB/c mice model. Place and Duration of Study: This study was performed in Laboratory of Bacteriology, University of Tarbiat Modares, Tehran, IRAN, 2011 and 2012. Methodology: BALB/c mice were immunized with different formulations three times orally followed by two times intramuscularly (i.m.) at 10 -day intervals. The protective effects of two component vaccines plus CpG Adjutants were assessed afterH. pyloriss1 challenge in different studies. The specific IgG antibodies titers in sera were studied by using ELISA, and Antigen specific IL -4, IL-10, IL-12, TGF�≤ and IFN -�≥ responses were measured in spleen of immunized mice after challenge using ELISA test. Clearance ofH. pyloricarried out according to standard protocol. Results:In this study the IgG1/IgG2a ratio in the mice immunized with r CagA and rCagA plus CpG was

Previous studies failed to demonstrate any role for the BIR1 domain of the inhibitor of apoptosis proteins (IAPs) in inhibition of executioner caspases. In this study, XIAP-BIR1-2 and c-IAP1-BIR1-2 domains have been used to investigate the role of BIR1 in the inhibition of caspase-7. Kinetic analysis confirmed that caspase-7 was inhibited in an uncompetitive manner at lower concentrations of XIAP-BIR1-2, whereas the inhibition was switched to the mixed type mode at higher concentrations of the inhibitor. In contrast, cIAP1-BIR1-2 inhibited caspase-7 in a mixed type mode at all examined concentrations. These data suggest that the presence of BIR1 is essential for inhibition of caspase-7 by cIAP1. Far-UV CD and fluorescence spectroscopy experiments showed that despite similar secondary structures, XIAP-BIR1-2 and cIAP1-BIR1-2 have different biophysical properties. BIR1-2 domain of XIAP was found to be more flexible than cIAP1, which may be the reason behind differences in their kinetic properties.

DNA vaccination using a plasmid encoding Human rotavirus A (HuRV-A) inner capsid VP2 was examined in a mouse model. BALB/c mice were immunized intranasally (i.n.) with a VP2 DNA vaccine that induced cellular and humoral immune response to HuRV-A. The increased levels of cytokines IFN-gamma and IL-4 and the production of anti-VP2 IgG antibodies were detected. In addition, splenocyte proliferation detected by MTT test was enhanced in the mice treated with the vaccine. These results may encourage the development of a HuRV-A DNA vaccine derived from the inner layer of viral capsid that can be administered i.n.

A system for the expression and characterization of VP2 protein of Human rotavirus A, strain G3 was established in the mammalian lung cell line (A549). Expression of the recombinant VP2 (rVP2) protein was detected 48-72 hrs after transfection by Western blotting. The rVP2 protein expressed in A549 cells formed intracellular core-like particles (CLPs) 30 nm in diameter detected by electron microscopy (EM). These results showed that the A549 cells are suitable as efficient eukaryotic host for production of rVP2 protein.

International audience; Carboxy-terminus of merozoite surface protein-1 (MSP-1(19) ) is the major protein on the surface of the plasmodial merozoite that acts as one of the most important blood-stage vaccine candidates. The present investigation was designed to evaluate the immune responses when either two recombinant antigens (rPvMSP-1(19) + rPfMSP-1(19)) or two plasmid constructs (pcDNA3.1 hygro-PvMSP-1(19) + pcDNA3.1 hygro-PfMSP-1(19)) were administered in combination at a single site in mice by using different immunization strategies (protein/protein, DNA/DNA and DNA/protein) at weeks 0, 5 and 8. All mice were monitored for the level of MSP-1(19) -specific antibody for up to 40 weeks. The inclusion of both recombinant antigens in a vaccine mixture could not inhibit induction of antibodies to the other antigen when the two recombinant antigens were combined in immunization formulation. Interestingly, antisera from immunized mice with either recombinant antigen failed to cross-react with heterologous antigen. Moreover, the results of this study showed that co-immunization with both antigens at a single site generated a substantial PvMSP-1(19) - and PfMSP-1(19) -specific antibody responses and also IFN-γ cytokine production (Th1 response) in DNA/protein prime-boost immunization strategies. The increased humoral response to PvMSP-1(19) and PfMSP-1(19) lasted nearly a year after immunization. Therefore, the results of this study are encouraging for the development of multi-species malaria vaccine based on MSP-1(19) antigen.