Application of a Fenton process for the pretreatment of an iron-containing oily sludge: A sustainable management for refinery wastes.

The feasibility of a Fenton-type process for the pretreatment of an oily refinery sludge has been explored taking advantage of the iron contained in the own sludge. This process reduces the content of total petroleum hydrocarbons (TPHs) accompanied by an increase in the total organic carbon concentration in the liquid phase. The effect of the temperature and the hydrogen peroxide loading was thoroughly studied in this work being the oxidant concentration the most critical parameter. Under 60 °C and 90 g/L of initial hydrogen peroxide concentration, the Total Organic Carbon (TOC) of the liquid phase was increased up values of 1336 mg/L and with a remarkable contribution of acetic acid as final oxidized compound (396 mgC/L). Additionally, nitrogen and phosphorous compounds were also dissolved in the aqueous phase achieving values of 250 mg/L and 7 mg/L for total Kjeldahl nitrogen and total phosphorous, respectively. Respirometry assays of the aqueous phase after the Fenton pretreatment have evidenced an increase of biodegradability up to 49% which makes this phase suitable for further biological processing in the refinery scheme. The reduction of the content of TPHs (61%) of the oily sludge, has also improved the settleability of the treated effluent (reducing the capillary suction time (CST) in ca. 88%).

Comprehensive characterization of an oily sludge from a petrol refinery: A step forward for its valorization within the circular economy strategy.

Refinery treatment plants produce large quantities of oily sludge during the petroleum refining processes. The hazardousness associated with the disposal of these wastes, make necessary the development of innovative technologies to handle it adequately, linked to the concepts of circular economy and environmental sustainability. This work provides for the first time a methodology for the deep characterization of this kind of wastes and consequently new insights regarding its valorization. A review of works dealing with the characterization of this type of wastes has been addressed evidencing the complexity and variability of these effluents. The oily sludge under study contains a high concentration of Chemical Oxygen Demand of 196 g COD/L, a Total Kjeldahl Nitrogen of 2.8 g TKN/kg, a phosphorous content as PO43- of 7 g/kg, as well as a great presence of heavy metals in a different range of concentrations. This sludge is composed of three different phases: oily, aqueous and solid. The oily and the solid phases present high percentages of carbon content (84 and 26%, respectively), related to the presence of alkanes ranged from n-C9 to n-C44. Therefore, it could be possible their valorization by the synthesis of catalyst and/or adsorbents. A dark fermentation process could be also proposed for the oily phase to obtain H2 as an alternative energy source. Finally, the aqueous phase contains low carbon and nutrients concentration. A previous thermal pre-treatment applied to the oily sludge might increase nutrient and organic loading in the aqueous phase due to solid destruction, making this aqueous effluent suitable for a further conventional biological treatment.

Antibody-Induced Internalization of the Human Respiratory Syncytial Virus Fusion Protein.

Respiratory syncytial virus (RSV) infections remain a major cause of respiratory disease and hospitalizations among infants. Infection recurs frequently and establishes a weak and short-lived immunity. To date, RSV immunoprophylaxis and vaccine research is mainly focused on the RSV fusion (F) protein, but a vaccine remains elusive. The RSV F protein is a highly conserved surface glycoprotein and is the main target of neutralizing antibodies induced by natural infection. Here, we analyzed an internalization process of antigen-antibody complexes after binding of RSV-specific antibodies to RSV antigens expressed on the surface of infected cells. The RSV F protein and attachment (G) protein were found to be internalized in both infected and transfected cells after the addition of either RSV-specific polyclonal antibodies (PAbs) or RSV glycoprotein-specific monoclonal antibodies (MAbs), as determined by indirect immunofluorescence staining and flow-cytometric analysis. Internalization experiments with different cell lines, well-differentiated primary bronchial epithelial cells (WD-PBECs), and RSV isolates suggest that antibody internalization can be considered a general feature of RSV. More specifically for RSV F, the mechanism of internalization was shown to be clathrin dependent. All RSV F-targeted MAbs tested, regardless of their epitopes, induced internalization of RSV F. No differences could be observed between the different MAbs, indicating that RSV F internalization was epitope independent. Since this process can be either antiviral, by affecting virus assembly and production, or beneficial for the virus, by limiting the efficacy of antibodies and effector mechanism, further research is required to determine the extent to which this occurs in vivo and how this might impact RSV replication.IMPORTANCE Current research into the development of new immunoprophylaxis and vaccines is mainly focused on the RSV F protein since, among others, RSV F-specific antibodies are able to protect infants from severe disease, if administered prophylactically. However, antibody responses established after natural RSV infections are poorly protective against reinfection, and high levels of antibodies do not always correlate with protection. Therefore, RSV might be capable of interfering, at least partially, with antibody-induced neutralization. In this study, a process through which surface-expressed RSV F proteins are internalized after interaction with RSV-specific antibodies is described. One the one hand, this antigen-antibody complex internalization could result in an antiviral effect, since it may interfere with virus particle formation and virus production. On the other hand, this mechanism may also reduce the efficacy of antibody-mediated effector mechanisms toward infected cells.

Biological removal of pharmaceutical compounds using white-rot fungi with concomitant FAME production of the residual biomass.

The efficiency of two white-rot fungi (WRF), Trametes versicolor and Ganoderma lucidum, to eliminate thirteen pharmaceutical pollutants with concomitant biodiesel production from the accumulating lipid content after treatment, was examined. The removal efficiency was studied using both individual and combined strains. The results of individual and combined strains showed a total removal (100%) of diclofenac (DCF), gemfibrozil (GFZ), ibuprofen (IBP), progesterone (PGT) and ranitidine (RNT). Lower removals were achieved for 4-acetamidoantipyrin (AAA), clofibric acid (ACF), atenolol (ATN), caffeine (CFN), carbamazepine (CZP), hydrochlorothiazide (HCT), sulfamethoxazole (SMX) and sulpiride (SPD), although the combination of both strains enhanced the system's efficiency, with removals ranging from 15 to 41%. This increase of the removal efficiency when combining both strains was attributed to the interactions developed between them (i.e., competition). Results from enzymatic and cytochrome P450 examination suggested that both extracellular (laccase, MnP, LiP) and intracellular oxidation mechanisms participate in the biological removal of pharmaceuticals. On the other hand, the "green" potential of the fungal sludge generated during the biological removal process was assessed for biodiesel production by means of one-step direct (in-situ) transformation. This process consists of the simultaneous extraction and conversion of lipids contained in the sludge by catalytic esterification/transesterification using a robust acid heterogeneous Zr-SBA-15 catalyst. This catalytic system provided conversions close to 80% of the saponifiable fraction (including free fatty acids and glycerides) in the presence of high amount of impurities. The overall weight FAME yield, based on the initial dried mass, was close to 30% for both strains.

Upgrading of solid recovered fuel (SRF) by dechlorination and catalytic pyrolysis over nanocrystalline ZSM-5 zeolite.

Globally increasing concern related to municipal solid waste generation is encouraging research efforts on developing alternative routes to valorize mixed refused wastes. In this way, catalytic pyrolysis is emerging as an interesting and efficient technology due to its great flexibility in terms of feedstock. In the current work, upgrading of a Solid Recovered Fuel (SRF) has been investigated by catalytic pyrolysis over nanocrystalline ZSM-5 zeolite (n-ZSM-5), paying special attention to dechlorination effects due to the high Cl content of the raw waste. Thus, pretreatment of the SRF by water washing and mild thermal processing allows for a significant reduction of the Cl concentration. Regarding the catalytic pyrolysis step, the best conditions correspond with a temperature of 400 °C in the catalyst bed and 0.50 catalyst/SRF mass ratio, which lead to ca. 30 wt% oil yield (rich in aromatic hydrocarbons) together with about 40 wt% gas yield (rich in C3-C4 olefins). Accordingly, these products could find use as raw chemicals or for the production of advanced fuels. In addition, zeolite reutilization has been tested for several cycles, denoting a progressive modification of the products distribution because of coke deposition. However, an almost total recovery of the n-ZSM-5 zeolite catalytic performance is achieved after regeneration by air calcination, affording the production of an oil fraction with a Cl content as low as 40 ppm.

Improvement of biogas production and nitrogen recovery in anaerobic digestion of purple phototrophic bacteria by thermal hydrolysis.

Purple phototrophic bacteria (PPB) are a novel driver to recover organics and nutrients from wastewater by assimilative growth. Depending on the source, assimilated resources from the PPB biomass can still be recovered after a releasing step. Anaerobic digestion (AD) releases carbonand nutrients, but the release is incomplete. Thermal hydrolysis (TH) as a pretreatment before AD improves the digestibility, release, and subsequent recovery potentials. This work determines the effects of TH in batch and continuous modes regarding methane potential, nutrients' release efficiencies, volatile solids destruction, degradability, and hydrolysis rates. Continuous runs over 165 days (d) confirmed enhanced recovery potentials, achieving up to 380 LCH4/kgVS (83 % solids destruction) and 73 % N release, respectively. The TH pretreatment is energy-intensive, but with appropriate heat recovery and increased methane production in the AD of the pretreated biomass, a combined configuration is energy positive.

Up-scale challenges on biopolymer production from waste streams by Purple Phototrophic Bacteria mixed cultures: A critical review.

The increasing volume of waste streams require new biological technologies that can address pollution concerns while offering sustainable products. Purple phototrophic bacteria (PPB) are very versatile organisms that present a unique metabolism that allows them to adapt to a variety of environments, including the most complex waste streams. Their successful adaptation to such demanding conditions is partly the result of internal polymers accumulation which can be stored for electron/energy balance or as carbon and nutrients reserves for deprivation periods. Polyhydroxyalkanoates, glycogen, sulphur and polyphosphate are examples of polymers produced by PPB that can be economically explored due to their applications in the plastic, energy and fertilizers sectors. Their large-scale production implies the outdoor operation of PPB systems which brings new challenges, identified in this review. An overview of the current PPB polymer producing technologies and prospects for their future development is also provided.

Eliminating a region of respiratory syncytial virus attachment protein allows induction of protective immunity without vaccine-enhanced lung eosinophilia.

In a murine model of respiratory syncytial virus disease, prior sensitization to the attachment glycoprotein (G) leads to pulmonary eosinophilia and enhanced illness. Three different approaches were taken to dissect the region of G responsible for enhanced disease and protection against challenge. First, mutant viruses, containing frameshifts that altered the COOH terminus of the G protein, were used to challenge mice sensitized by scarification with recombinant vaccinia virus (rVV) expressing wild-type G. Second, cDNA expressing these mutated G proteins were expressed by rVV and used to vaccinate mice before challenge with wild-type respiratory syncytial virus (RSV). These studies identified residues 193-205 to be responsible for G-induced weight loss and lung eosinophilia and showed that this region was not was not necessary for induction of protective immunity. Third, mice were sensitized using an rVV that expressed only amino acids 124-203 of the G protein. Upon RSV challenge, mice sensitized with this rVV developed enhanced weight loss and eosinophilia. This is the first time that a region within RSV (amino acids 193-203) has been shown to be responsible for induction of lung eosinophilia and disease enhancement. Moreover, we now show that it is possible to induce protective immunity with an altered G protein without inducing a pathological response.

Catalytic wet hydrogen peroxide oxidation of a petrochemical wastewater.

Continuous Catalytic Wet Hydrogen Peroxide Oxidation (CWHPO) for the treatment of a petrochemical industry wastewater has been studied on a pilot plant scale process. The installation, based on a catalytic fixed bed reactor (FBR) coupled with a stirred tank reactor (STR), shows an interesting alternative for the intensification of a continuous CWHPO treatment. Agglomerated SBA-15 silica-supported iron oxide (Fe(2)O(3)/SBA-15) was used as Fenton-like catalyst. Several variables such as the temperature and hydrogen peroxide concentration, as well as the capacity of the pilot plant for the treatment of inlet polluted streams with different dilution degrees were studied. Remarkable results in terms of TOC reduction and increased biodegradability were achieved using 160 degrees C and moderate hydrogen peroxide initial concentration. Additionally, a good stability of the catalyst was evidenced for 8 hours of treatment with low iron leaching (less than 1 mg/L) under the best operating conditions.

Exploring the inhibition boundaries of mixed cultures of purple phototrophic bacteria for wastewater treatment in anaerobic conditions.

The development of novel wastewater platforms should include the analysis of the most critical functional factors including the effects of toxic or inhibitory substances. Due to the novelty of purple phototrophic bacteria (PPB)-based wastewater treatment systems, this analysis has not been done yet in mixed cultures. In this work, various relevant chemical compounds, including aromatic (phenol, 2,4,6-trichlorophenol or 246TCP, 4-nitrophenol or 4CP, sulfathiazole) and aliphatic organics (methanol, trichlorethylene or TCE, oleic acid, ethanol, propionic acid), inorganic salts (ammonium, ClO3-, Na+), and metals (Fe3+, Fe2+, Cu2+, Zn2+, Ni2+, Al3+), as well as pH, are analyzed for their effect on mixed PPB cultures in anaerobic photoheterotrophic conditions using acetate as the model organic substrate. The most toxic substances detected were 246TCP, 4NP, Cu2+, Fe2+ and Ni2+, (Ki for activity: 23 ± 2, 97 ± 12, 3.1 ± 0.4, 13 ± 3, 13 ± 1 mg/L, and Ki (or toxicity threshold) for growth: 17 ± 2, (119), 3.5 ± 0.4, (4.8), (22.9) mg/L, respectively). Some substances inhibited the activity more than the growth (sulfathiazole, Ni2+ and Fe3+), or the growth more than the activity (TCE, 4NP and Fe2+). In addition, some organic substrates, such as phenol, ethanol and propionate, specifically inhibited the acetate uptake, being noncompetitive in the case of phenol and ethanol, and most likely competitive in the case of propionate. These findings are relevant for the wastewater treatment and resource recovery applications of the PPB technology, as well as for the upgrading of current models (Photo-Anaerobic Model). In addition, the data will open possibilities to promote the production of specific compounds (as PHA or single-cell proteins) by selectively inhibiting some parts of the PPB metabolism.

Contamination of N-poor wastewater with emerging pollutants does not affect the performance of purple phototrophic bacteria and the subsequent resource recovery potential.

Propagation of emerging pollutants (EPs) in wastewater treatment plants has become a warning sign, especially for novel resource-recovery concepts. The fate of EPs on purple phototrophic bacteria (PPB)-based systems has not yet been determined. This work analyzes the performance of a photo-anaerobic membrane bioreactor treating a low-N wastewater contaminated with 25 EPs. The chemical oxygen demand (COD), N and P removal efficiencies were stable (76 ±â€¯8, 62 ±â€¯15 and 36 ±â€¯8 %, respectively) for EPs loading rate ranging from 50 to 200 ng L-1 d-1. The PPB community adapted to changes in both the EPs concentration and the organic loading rate (OLR) and maintained dominance with >85 % of total 16S gene copies. Indeed, an increment of the OLR caused an increase of the biomass growth and activity concomitantly with a higher EPs removal efficiency (30 ±â€¯13 vs 54 ±â€¯11 % removal for OLR of 307 ±â€¯4 and 590 ±â€¯8 mgCOD L-1 d-1, respectively). Biodegradation is the main mechanism of EPs removal due to low EPs accumulation on the biomass, the membrane or the reactor walls. Low EPs adsorption avoided biomass contamination, resulting in no effect on its biological methane potential. These results support the use of PPB technologies for resource recovery with low EPs contamination of the products.

Integrated heterogeneous sono-photo Fenton processes for the degradation of phenolic aqueous solutions.

The removal of organic compounds from aqueous solutions has been tackled by a novel integrated heterogeneous system. The efficacy of the different systems has been assessed using Fenton-like processes (H2O2/Fe2O3-SBA-15) and phenol as model pollutant. Sono- and photo-Fenton processes separately applied as well as combined systems were studied in order to evaluate of possible beneficial effects on the use of coupled systems. The sequential system evidences an enhancement in terms of phenol and TOC conversions compared to the ultrasound or UV-light irradiation processes. A total phenol degradation and ca. 90% TOC reduction are achieved by sequentially ultrasound followed by UV-visible light irradiation. These effects are ascribed cavitation effect of ultrasound producing a reduction of particle size that provides a higher amount of available active sites due to an increased surface area for the subsequent photo-Fenton system. These encouraging results open new paths for the existing oxidation technologies for potable water and wastewater treatment.

Inhibiting Human Parainfluenza Virus Infection by Preactivating the Cell Entry Mechanism.

Paramyxoviruses, specifically, the childhood pathogen human parainfluenza virus type 3, are internalized into host cells following fusion between the viral and target cell membranes. The receptor binding protein, hemagglutinin (HA)-neuraminidase (HN), and the fusion protein (F) facilitate viral fusion and entry into the cell through a coordinated process involving HN activation by receptor binding, which triggers conformational changes in the F protein to activate it to reach its fusion-competent state. Interfering with this process through premature activation of the F protein has been shown to be an effective antiviral strategy in vitro. Conformational changes in the F protein leading to adoption of the postfusion form of the protein-prior to receptor engagement of HN at the host cell membrane-render the virus noninfectious. We previously identified a small compound (CSC11) that implements this antiviral strategy through an interaction with HN, causing HN to activate F in an untimely process. To assess the functionality of such compounds, it is necessary to verify that the postfusion state of F has been achieved. As demonstrated by Melero and colleagues, soluble forms of the recombinant postfusion pneumovirus F proteins and of their six helix bundle (6HB) motifs can be used to generate postfusion-specific antibodies. We produced novel anti-HPIV3 F conformation-specific antibodies that can be used to assess the functionality of compounds designed to induce F activation. In this study, using systematic chemical modifications of CSC11, we synthesized a more potent derivative of this compound, CM9. Much like CSC11, CM9 causes premature triggering of the F protein through an interaction with HN prior to receptor engagement, thereby preventing fusion and subsequent infection. In addition to validating the potency of CM9 using plaque reduction, fusion inhibition, and binding avidity assays, we confirmed the transition to a postfusion conformation of F in the presence of CM9 using our novel anti-HPIV3 conformation-specific antibodies. We present both CM9 and these newly characterized postfusion antibodies as novel tools to explore and develop antiviral approaches. In turn, these advances in both our molecular toolset and our understanding of HN-F interaction will support development of more-effective antivirals. Combining the findings described here with our recently described physiologically relevant ex vivo system, we have the potential to inform the development of therapeutics to block viral infection.IMPORTANCE Paramyxoviruses, including human parainfluenza virus type 3, are internalized into host cells by fusion between viral and target cell membranes. The receptor binding protein, hemagglutinin-neuraminidase (HN), and the fusion protein (F) facilitate viral fusion and entry into cells through a process involving HN activation by receptor binding, which triggers conformational changes in F to activate it to reach its fusion-competent state. Interfering with this process through premature activation of the F protein may be an effective antiviral strategy in vitro We identified and optimized small compounds that implement this antiviral strategy through an interaction with HN, causing HN to activate F in an untimely fashion. To address that mechanism, we produced novel anti-HPIV3 F conformation-specific antibodies that can be used to assess the functionality of compounds designed to induce F activation. Both the novel antiviral compounds that we present and these newly characterized postfusion antibodies are novel tools for the exploration and development of antiviral approaches.

Toxicity assessment of pharmaceutical compounds on mixed culture from activated sludge using respirometric technique: The role of microbial community structure.

Micropollutants of emerging concern such as pharmaceuticals can significantly affect the performance of secondary biological processes in wastewater treatment plants. The present study is aimed to evaluate the toxicity and inhibition of three pharmaceutical compounds (caffeine, sulfamethoxazole and carbamazepine) on two cultures of microbial consortia enriched from wastewater aerobic activated sludge. One of them was acclimated to pharmaceuticals and the other was non-acclimated as control bioassay. The toxic and inhibitory effects on these cultures were assessed by respirometric tests through the oxygen uptake rate as an indicator of their capacity to degrade a readily available carbon source. Higher values of toxicity and inhibition of pharmaceutical compounds were observed for the control culture as compared to the acclimated one. Sulfamethoxazole and carbamazepine exhibited higher toxicity and inhibition effects than caffeine in both acclimated and control cultures. The microbial diversity of the two cultures was also studied. The composition of microbial community of acclimated and control cultures, was determined by targeting the 16S ribosomal RNA gene. It was observed that Proteobacteria was the most abundant phylum, with Gammaproteobacteria dominating both cultures. Control culture was dominated by Gammaproteobacteria and mostly by the genera Pseudomonas and Sodalis, which belong to common families present in wastewater. Results suggested that the acclimated culture to the three pharmaceuticals was mostly comprised of the extremely multiresistant genera Escherichia-Shigella (38%) of Gammaproteobacteria, resulting to higher resistance as compared to the control culture (Escherichia-Shigella, 7%). Finally, the microbial structure of the microorganisms present in a real bioreactor, which was initially seeded with the acclimated culture and fed in a continuous mode with the selected pharmaceuticals, was also analyzed. The continuous loading of pharmaceuticals in the bioreactor affected its microbial diversity, leading to the dominance of Betaproteobacteria and to the resistant genus Rhizobium of Alphaproteobacteria.

Catalytic wet peroxidation of phenol in a fixed bed reactor.

Iron-containing mesostructured materials (Fe-SBA-15) are suitable for continuous treatment of phenolic aqueous solutions by means of catalytic wet peroxide oxidation (CWPO) in a packed-bed reactor. These materials were successfully extruded, crushed and sieved with a particle size ranging from 1 to 1.6 mm using mineral clay and methyl cellulose as binders. Non-significant changes have been found in the textural and structural properties of the extruded material in comparison to the parent powder Fe-SBA-15 material. Activity of extruded catalyst in terms of phenol degradation and TOC reduction has been monitored in a continuous mode. The increase of residence time enhances significantly the TOC degradation. The catalyst stability, taking into account the loss of iron species from the catalyst into the aqueous solution, has also been examined. The catalytic results of Fe-SBA-15 material in comparison to a homogeneous catalytic test prove the relevant role of the solid catalyst in the oxidation process.

Wastewater sludges pretreated by different oxidation systems at mild conditions to promote the biogas formation in anaerobic processes.

The effect of different oxidation processes at mild conditions including the coupled-Fenton (sono-Fenton, photo-Fenton, and sono-photo-Fenton) and their blank systems (ultrasound, ultraviolet, zero valent iron, and Fenton) on anaerobic digestion of the sludge for biogas production was investigated. Ultrasounds led to the highest organic matter solubilization (3.8 up to 5.2 g chemical oxygen demand (COD)/L, for the raw and treated sludge, respectively), while for the rest, organic matter transformation was observed resulting in an almost soluble COD net balance. Results indicated that for the most oxidative processes, the released organic matter was probably mineralized by the hydroxyl radicals produced during the treatments. It is interesting to remark that even if the biochemical methane potential was barely enhanced by the different methods applied, all the methods demonstrated to enhance the overall kinetics of the biomethanation processes, increasing the rapidly biodegradable fraction of the sludge.

Subcellular distribution of DNA-binding proteins from cultured hamster fibroblasts.

The distribution between nuclei and cytoplasm of DNA-binding proteins from growing NIL cells was studied. To obtain the subcellular fractions, cell monolayers or cells previously detached from the culture dish were treated with non-ionic detergent N onidet P-40. Proteins with affinity for DNA were isolated from nuclear or cytoplasmic fractions by chromatography on DNA-cellulose columns and were further analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. The results show that P8, one of the major components in the 0.15 M NaC1-eluted proteins, is found predominantly in the cytoplasmic fractions, whereas P6, the other main protein peak in this eluate, is more prominent in the nuclear fraction. Among the other proteins eluted at 0.15 M NaC1 from the DNA-cellulose column, P5 and P5' are detected in both nuclear and cytoplasmic fractions. All the other proteins in the 0.15 M NaC1 eluate are present almost exclusively in the cytoplasmic fraction. On the other hand, most of the proteins with higher affinity for DNA, eluted from the column at 2 M NaC1, are present in the nuclear fraction, although they are also detected in the cytoplasm in amounts similar to those observed in the nuclei.

Activity and resistance of iron-containing amorphous, zeolitic and mesostructured materials for wet peroxide oxidation of phenol.

Iron-containing materials have been prepared following several strategies of synthesis and using different silica supports (amorphous, zeolitic and mesostructured materials). Activity and stability of these materials was evaluated on the wet peroxide oxidation of phenol under mild reaction conditions (100 degrees C, air pressure of 1MPa and stoichiometric amount of hydrogen peroxide for the complete mineralisation of phenol). Their catalytic performance was monitored in terms of phenol and total organic carbon (TOC) conversions, by-products distribution (aromatics compounds and carboxylic acids) and degree of metal leached into the aqueous solution. The nature and local environment of iron species is strongly dependent on the synthetic route, which dramatically influences their catalytic performance. Crystalline iron oxide species supported over mesostructured SBA-15 materials have demonstrated to be the most interesting catalysts for phenol degradation according to its high organic mineralisation, low sensitivity to leaching out and good oxidant efficiency.

Oriented synthesis and cloning of influenza virus nucleoprotein cDNA that leads to its expression in mammalian cells.

The influenza virus nucleoprotein gene has been cloned by a procedure that involves direct cDNA synthesis onto the primer-vector pBSV9, a pBR322-SV40 recombinant plasmid. dT-tailed pBSV9 was used to prime the synthesis of cDNA on a template of in vitro synthesized viral mRNA. The synthesis of ds-cDNA was initiated by a specific oligodeoxynucleotide and the resulting recombinant was circularized by intramolecular ligation. Recombinant pSVa963 contained the viral nucleoprotein gene directly fused to the SV40 early promoter region included in pBSV9 and followed by a dA:dT tail and the SV40 polyadenylation signal. When pSVa963 was used to transfect COS-1 cells, the presence of three NP-specific mRNAs of 1600, 1900 and 2500 nucleotides in length could be detected. Pulse labelling experiments of COS-1 transfected cells and immunobinding to a nucleoprotein monoclonal antibody indicated the synthesis of nucleoprotein. This nucleoprotein accumulated in the nucleus of transfected cells at a level similar to that found in infected cells. The vector and method described may be useful for the specific cloning and expression of any mRNA for which a 5'-terminal sequence is known.

Nucleotide sequence of the fusion and phosphoprotein genes of human respiratory syncytial (RS) virus Long strain: evidence of subtype genetic heterogeneity.

The nucleotide and deduced amino acid sequences of the fusion (F) and phosphoprotein (P) genes of the Long strain of human respiratory syncytial (RS) virus have been determined from cDNA copies cloned into pBSV9 shuttle vector. Comparison of these sequences with their counterparts of other strains reveals genetic heterogeneity within the same subtype. The percentage of nucleotide and amino acid changes occurring in both proteins is similar. Thus, the Long F and P proteins share 97.9% and 98.3% amino acid identity, respectively, with their homologs of the A2 strain. Nevertheless the F2 subunit of the fusion protein accumulates 3.1 times more amino acid changes than the F1 subunit. In addition, the percentage of nucleotide changes in the 3' extracistronic sequences is 6 times higher in the P than in the F gene. These results are discussed in terms of selective pressures operating in the evolution of RS virus in nature.