8 research outputs found
Exo-polygalacturonase production by Penicillium roqueforti on pumpkin oil cake in solid state fermentation
The feasibility of using pumpkin oil cake (PuOC), individual and in combination with wheat bran (WB), as substrate for the production of Exo-polygalacturonase (Exo-p) by starter culture Penicillium roqueforti in solid state fermentation (SSF) has been evaluated. The kinetics of enzyme production was investigated using PuOC alone in the range from 13 to 168 h, with moisture contents varying from 44% the ability to grow and produce Exo-p activity on this substrate, reaching a maximum value of 1451.75 U/g.d.w PuOC by the 5th day of fermentation. Fermentation experiments indicated that the water activity (aw) influenced the enzyme production. A medium with aw 0.932 and the fermentation time of 5 days were selected, as these conditions resulted in the highest pectolytic activity and were used for further investigation. A next step in this research was to examine the effect of the substrate combination, PuOC with wheat bran (WB), in different ratios. The addition of WB as carbon sources was found to have a significant influence on the enzymes yields. Exo-p activities were the highest with initial water activity of a w 0.932 and PuOC supplementation with WB (1:0.67)
Phytomedical investigation of Najas minor All. in the view of the chemical constituents
Plants are an abundant natural source of effective antibiotic compounds. Phytomedical investigations of certain plants haven’t still been conducted. One of them is Najas minor (N. minor), an aquatic plant with confirmed allelopathy. Research conducted in this study showed the influence of water and ethyl acetate extracts of N. minor on microorganisms, in the view of chemical profiling of volatile constituents and the concentrations of total phenols, flavonoids and tannins. Antimicrobial activity was defined by determining minimum inhibitory and minimum microbicidal concentrations using microdilution method. Influence on bacterial biofilm formation was performed by tissue culture plate method. The total phenolics, flavonoids and condensed tannins were determined by Folin-Ciocalteu, aluminum chloride and butanol-HCl colorimetric methods. Chemical profiling of volatile constituents was investigated by GC and GC-MS. Water extract didn't have antimicrobial activity below 5000 µg/mL. Ethyl acetate extract has shown strong antimicrobial activity on G+ bacteria - Staphylococcus aureus PMFKGB12 and Bacillus subtilis (MIC < 78.13 µg/mL). The best antibiofilm activity was obtained on Escherichia coli ATCC25922 (BIC50 at 719 µg/mL). Water extract had higher yield. Ethyl acetate extract had a significantly greater amount of total phenolics, flavonoids and tannins. As major constituent hexahydrofarnesyl acetone was identified. The ethyl acetate extract effected only G+ bacteria, but the biofilm formation of G-bacteria was suppressed. There was a connection between those in vivo and in vitro effects against pathogenic bacterial biofilm formation. All of this points to a so far unexplored potential of N. minor
Electrodeposition of Nb and Al from chloroaluminate melt on vitreous carbon
Niobium and aluminium were electrodeposited at 200 °C under argon atmosphere onto vitreous carbon from inorganic chloroaluminate melts (AlCl3+NaCl) with added niobium. Niobium was introduced into the electrolyte by anodic dissolution of metallic niobium or by chemical dissolution of Nb2O5 in a melt of equimolar AlCl3+NaCl mixture. The processes of deposition/dissolution onto/from vitreous carbon were investigated by cyclic voltammetry and chronoamperometry. Characterization of the obtained deposits was done by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The only observed reduction processes on the working electrode in the potential window from 1.000 V to – 1.000 V vs. Al, were individual niobium deposition and codeposition of niobium and aluminium with Al-Nb alloys formation. Electrodeposition of niobium from the chloroaluminate melt with added niobium (V) oxide seems to start at around – 0.100 V vs. Al and at about – 0.200 V vs. Al aluminium starts codepositing. During the codeposition Nb-Al alloys were formed. Niobium deposition starting potential from the electrolyte with niobium added by anodic dissolution starts at 0.100 V vs. Al, and aluminium codeposition starting potential was at around – 0.025 V vs. Al, followed by Nb/Al alloy formation
Paratopic specificity of two human monoclonal immunoglobulins M expressing Y7 idiotype
We have already characterized Y7 idiotype as natural idiotype by showing its expression on IgM molecules derived form cord sera. The aim of this study was to investigate the binding properties of two human monoclonal IgM antibodies isolated from the sera of patients with Waldenstrom macroglobulinaemia, which express Y7 idiotype. In order to estimate the binding repertoire of these two IgM molecules (IgM DJ and IgM RD) we tested the isolated IgM molecules and their F(ab)2 and Fab fragments over the panel of 23 different protein and non-protein antigens, nine different bacterial strains and cell membranes from neuronal and epithelial tissues. These tests were performed by means of direct and competitive ELISA, immunoblot and immunofluorescence assays. Both antibodies reacted with ssDNA, oligonucleotide fragments, and lactobacteria. IgM DJ showed reactivity with myelin associated glycoprotein (MAG) and blood vessel endothelial cells. Binding for DNA oligonucleotide fragments and lactobacteria was interrupted up to 70% with 0.5 M NaCl, which indicated that these interactions were of low affinity. Avidity dependent binding was also evidenced by use of F(ab)2 fragments. Determined characteristics such as polyreactivity which included autoantigens, low affinity and avidity dependent binding, qualified these two monoclonal IgM as natural autoantibodies. Expression of natural idiotype Y7 on two immunoglobulins M,which possessed natural autoantibody properties, indicated the connection of natural autoantibody specificity and the natural idiotype expression and suggested the involvement of network interactions in selection of malignant B cell clones
Electrodeposition of Nb and Al from chloroaluminate melt on vitreous carbon
Niobium and aluminium were electrodeposited at 200 °C under argon atmosphere onto vitreous carbon from inorganic chloroaluminate melts (AlCl3+NaCl) with added niobium. Niobium was introduced into the electrolyte by anodic dissolution of metallic niobium or by chemical dissolution of Nb2O5 in a melt of equimolar AlCl3+NaCl mixture. The processes of deposition/dissolution onto/from vitreous carbon were investigated by cyclic voltammetry and chronoamperometry. Characterization of the obtained deposits was done by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS). The only observed reduction processes on the working electrode in the potential window from 1.000 V to – 1.000 V vs. Al, were individual niobium deposition and codeposition of niobium and aluminium with Al-Nb alloys formation. Electrodeposition of niobium from the chloroaluminate melt with added niobium (V) oxide seems to start at around – 0.100 V vs. Al and at about – 0.200 V vs. Al aluminium starts codepositing. During the codeposition Nb-Al alloys were formed. Niobium deposition starting potential from the electrolyte with niobium added by anodic dissolution starts at 0.100 V vs. Al, and aluminium codeposition starting potential was at around – 0.025 V vs. Al, followed by Nb/Al alloy formation
Expression of Y7 cross-reactive idiotope on human IgM molecules
In this paper we report data regarding the IgM Y7 cross-reactive idiotope (CRIo) obtained by analysis of: 1) its V-gene subgroup dependance, 2) the frequency of its expression on human monoclonal IgMs and IgM molecules from normal and pathological sera. Furthermore, comparison of epitopic repertoire and nature of binding of human monoclonal IgMs expressing Y7 CRIo was performed to confirm the natural antibody properties of these molecules. IgM isolated from sera of patient DJ (IgM DJ) which expresses the Y7 idiotope has been classified to V(H)3/V(L)2 subgroup. From ten IgMs tested only IgM from patient RD (IgM RD) has been shown to express Y7 idiotope. Y7(+) human IgMs bound to ssDNA, lactic acid bacteria, mouse laminin, porcine thyroglobulin and mouse IgG. Higher percentage of the expression of Y7 CRIo was detected in the sera of patients suffering from autoimmune diseases such as lupus, rheumatoid arthritis and psoriasis vulgaris as well as in patients suffering from chronic infections of the lower urinary tract. Antigen binding repertoire and properties of Y7(+) monoclonal IgM, frequency of Y7 expression on monoclonal IgMs and its concentration in normal and pathological sera indicate the important biological role of this CRIo within the immune system
Seroprevalence of Mycoplasma bovis in grazing dairy cows from five different areas in Serbia
Mycoplasma bovis infection in grazing dairy cows has not been reported in the Republic of Serbia to date. It is important to monitor its seroprevalence on the field. The presence of specific antibodies against M bovis in the blood serum of grazing daily cows is investigated in the present study. A total of 131 blood serum samples of clinically healthy dairy cows were examined. Sampling was performed during 2013 from five different areas in Serbia: Zasavica, Pozarevac, Gruza, Novi Sad and Banatski Karlovac. A commercial ELISA kit for diagnosis of M bovis antibodies in blood serum samples, manufactured by Bio-X Diagnostics, Belgium, was used. Specific antibodies against M. bovis were identified in 13 out of 131 samples (9.92%) from 4 locations; the only negative location was the most southern Gruza. The revealed seroprevalence is evidence for the presence of M. bovis in grazing dairy cows in different locations of Serbia