Phosphorus bioavailability of biochars produced by thermo‐chemical conversion

Recycling of P is a common strategy in efficient use of P. The aims of our investigation were to study the P extractability of biochars produced by low temperature conversion and to determine the effect of soda application on low‐temperature conversion of organic compounds and the bioavailability of P to rye grass (Lolium perenne L., cv. Grazer). In this study canola cake, dried distillers grains with solubles, and meat‐and‐bone meal were converted to biochars with thermo‐chemical conversion at 400°C. The P availability was measured in terms of solubility in water, 2% citric, and 2% formic acid, and in a pot experiment with rye grass (Lolium perenne L.) which was cut three times. Application of 8% (w/w) soda to the process of thermo‐chemical conversion of canola cake, dried distillers grains with soluble and meat‐and‐bone meal resulted in an increase of water‐, 2% citric‐, and 2% formic‐acid‐extractable P in the biochars. In contrast to the application of soda, addition of 12% wood ash (w/w) to the conversion of dried distillers grains with solubles resulted in a lower increase of water‐soluble P in the corresponding biochar compared to processing biochar without additives. Addition of biochar P (100 mg P [kg soil]^–1) to a Luvisol resulted in an increase of CAL‐extractable soil P. The P uptake of rye grass from biochars produced with the addition of soda was as effective as basic slag and MgNH₄ phosphate fertilizers and even better than rock phosphate.     

Assistance of microbial glycolipid antigen processing by CD1e

Complexes between CD1 molecules and self or microbial glycolipids represent important immunogenic ligands for specific subsets of T cells. However, the function of one of the CD1 family members, CD1e, has yet to be determined. Here, we show that the mycobacterial antigens hexamannosylated phosphatidyl-myo-inositols (PIM6) stimulate CD1b-restricted T cells only after partial digestion of the oligomannose moiety by lysosomal alpha-mannosidase and that soluble CD1e is required for this processing. Furthermore, recombinant CD1e was able to bind glycolipids and assist in the digestion of PIM6. We propose that, through this form of glycolipid editing, CD1e helps expand the repertoire of glycolipidic T cell antigens to optimize antimicrobial immune responses.     

Effectiveness of donor natural killer cell alloreactivity in mismatched hematopoietic transplants

T cells that accompany allogeneic hematopoietic grafts for treating leukemia enhance engraftment and mediate the graft-versus-leukemia effect. Unfortunately, alloreactive T cells also cause graft-versus-host disease (GVHD). T cell depletion prevents GVHD but increases the risk of graft rejection and leukemic relapse. In human transplants, we show that donor-versus-recipient natural killer (NK)-cell alloreactivity could eliminate leukemia relapse and graft rejection and protect patients against GVHD. In mice, the pretransplant infusion of alloreactive NK cells obviated the need for high-intensity conditioning and reduced GVHD. NK cell alloreactivity may thus provide a powerful tool for enhancing the efficacy and safety of allogeneic hematopoietic transplantation.     

A study of the prevalence and genotypes of Giardia duodenalis infecting kennelled dogs

Giardia duodenalis is a protozoan parasite of animals that is zoonotic. Given the capacity of this organism to spread via the faecal–oral route, animals held in overcrowded and unhygienic conditions are at high risk of infection. Faecal samples from dogs in three kennels in Rome were examined by microscopy and PCR for G. duodenalis, and the prevalence data generated were correlated with variables such as kennel identity, age of dog, length of time the dog had been kennelled and clinical signs.The overall prevalence of the parasite in the faecal samples was 20.5% and was higher in samples from the largest kennel, which had the greatest turnover of dogs, and in faecal samples from younger animals. Giardia cysts were found more frequently in diarrhoeic animals but were also found in dogs with no clinical signs. Although the finding that the majority of isolates were dog-specific rather than zoonotic genotypes suggests that the zoonotic risk from this pathogen is less than previously thought, the higher prevalence of infection in younger dogs may pose a specific public health issue as such animals are more frequently re-homed with families.     

Shifts in the Holstein dairy cow milk fat globule membrane proteome that occur during the first week of lactation are affected by parity

Background: The milk fat globule membrane(MFGM) proteomes of colostrum and transition milk are rich sources of proteins that are likely important for neonatal calf health. In addition, characterization of these proteomes could also yield valuable information regarding mammary gland physiology of the early postpartum lactating cow. The objectives of this research were to characterize the MFGM proteomes of colostrum and transition milk through sample collections at four timepoints postpartum, including the first milking(M1, colostrum), second milking(M2, transition milk), fourth milking(M4, transition milk), and fourteenth milking(M14, mature milk), and compare these proteomes between multiparous(MP; n = 10) and primiparous(PP; n = 10) Holstein dairy cows. Isolated MFGM proteins were labeled using Tandem Mass tagging and analyzed using liquid chromatography-tandem mass spectrometry(LC-MS/MS). Protein identification was completed using MASCOT and Sequest in Proteome Discoverer 2.2. The scaled abundance values were analyzed using PROC MIXED in SAS to determine the effects of milking(MIL), parity(PAR), and MIL × PAR. The adaptive false-discovery rate(FDR)-adjusted P values were determined using PROC MULTTEST. Protein characterization and bioinformatic analysis were completed using a combination of PANTHER, Blast, and Uniprot.Results: A total of 104 common proteins were identified in each of the MFGM samples. Statistical analysis revealed that70.2% of identified proteins were affected by MIL. Of these, 78.1% were lower in M14 compared with M1, including immune-related proteins lactotransferrin, lactadherin and hemopexin. Parity affected 44.2% of proteins. Of the proteins affected by PAR, 84.8% were higher in MP cows compared with PP cows, including apolipoprotein E and histones 2 A, 2 B, 3,and 4 b. Butyrophilin subfamily 1 member 1 A and annexin 5 were higher in samples from PP cows. Milking × parity affected32.7% of identified proteins, including lactotransferrin, gelsolin, vitamin D binding protein, and S100 proteins.Conclusions: This research supports previous findings that the Holstein MFGM proteome changes rapidly during the first week of lactation. In addition, this research identifies the impact of parity on the colostrum and transition milk MFGM proteomes, which may be important for milk-fed calf health or for the identification of protein biomarkers for mammary functionality.     

Polycyclic Aromatic Hydrocarbons (PAHs) Slurry Phase Bioremediation of a Manufacturing Gas Plant (MGP) Site Aged Soil

Bench scale tests have been carried out in order to investigatebioremediation feasibility of a Manufacturing Gas Plant site(Bovisa Gasometri – MI – I) aged soil, highly contaminated bypolyaromatic hydrocarbons (PAHs) and mineral oils. Biodegradationstudies were carried out at 22 °C in a slurry system reactor, with a solid to liquid ratio of 10% w/w. Three testswere performed, over a period of 23, 24 and 91 days respectively.In the first test, only soil and water were put into the system.In the second test, microbial activity was inhibited to evaluatethe amount of abiotic losses. In the third test, macronutrientswere added to the reactor; bioaugmentation was also carried outby an inoculum of autochthonous PAH-degrading microorganisms. Saturated hydrocarbons, PAHs, transformation products, heterotropic and PAH-degrading bacteria and fungi were monitored.Tests showed that high removal efficiency could be obtained following 23 days of treatment for all PAHs, including high molecular weight compounds. Abiotic losses were an importantprocess contributing to concentration abatement in soil, especially in the first phase of the treatment. Lag time lackfor all polyaromatic hydrocarbons revealed that autochthonousmicroorganisms were well adapted to these contaminants; bioaugmentation did not seem to speed up the process. The higherremoval rate and efficiency for high molecular weight PAHs obtained in the third test suggested that nutrient addition could play an important role in the biodegradation process ofthese compounds, whereas it did not significantly modify total(abiotic + biotic) removal of light compounds.     

Influence of environmental factors on the biological treatment of organic compounds in contaminated lagoon sediments

Background and Scope  Many technologies available to remediate soils are not cost-effective when applied to marine and lagoon sediments, due to the physico-chemical characteristics of these matrices (high percentages of small particle size material, high moisture and organic matter content, many different types of inorganic and organic contamination). For these types of waste, slurry phase bioreactors can provide versatile processes, with very high removal efficiencies of recalcitrant organic compounds. The biodegradation of these contaminants strictly depends on the specific structure of the molecules and on environmental factors, such as the dissolved oxygen concentration, salinity, pH, and macronutrient availability. This paper presents the results of lab-scale tests performed to investigate the effect of the above-mentioned factors on the removal efficiency of saturated hydrocarbons, polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBs) in slurry phase biological treatment of lagoon sediments. Methods  Sediments were contaminated by saturated hydrocarbons (958 mg/kg d.w.), polyaromatic hydrocarbons (PAHs) (29 mg/kg d.w.) and polychlorobiphenyls (PCBs) (236 μg/kg d.w.). Carbon to nitrogen to phosphorous ratios in the matrix were not properly balanced for biological treatment. High concentrations of metals were also present (Cu: 200 mg/kg d.w.; Zn: 1710 mg/kg d.w.; As: 33 mg/kg d.w.; Cd: 13 mg/kg d.w.; Pb: 244 mg/kg d.w.). Biodegradation studies were carried out at 21 ± 1°C, in completely mixed slurry phase aerobic, anaerobic and sequential anaerobic/aerobic batch systems (3.5 1), with a solid to liquid ratio of 10% w/w. Where required, anaerobic conditions occurred naturally within three days of not aerated treatment. The aerated reactors were also equipped with traps for the waste vapors. Twelve tests were performed, over a period between ten and twenty-two days, mixing water, sediments and different amounts of various additives (macronutrients to balance C:N:P to 100:10:1 w/w, sodium chloride from 0 to 20 g/1, pH buffer solution) in the reactors, depending on the test being performed. Results and Discussion  No significant differences among the removal efficiencies of saturated hydrocarbons in tests could be observed. Abatements between 63% and 93% were obtained. The dissolved oxygen concentration was the most critical factor affecting the treatment of PAHs. Removal efficiencies below 20% were obtained for two and three-ring PAHs in the non-aerated tests. Higher values, between 45% and 61%, were obtained for these compounds in the aerated treatments; however, large (16% to 21%) abiotic losses (volatilization) were observed in these cases. Four-ring PAH removal efficiency was below 5% in all the non-aerated treatments, except for test performed without additions (30%); in the aerobic processes, removal efficiencies between 40% and 50% were obtained, except for test performed with nutrient addition and 10 g NaCl/1 (16%). Abatements of five and six-ring PAHs were between 43% and 69% in the aerated tests, and between 17% and 51% in the non-aerated treatments. Concerning PCBs, tests evidenced that reductive dehalogenation mechanisms have occurred in the anaerobic reactors with the most stable pH values, resulting in an increase of 2,4,4′-CB and 2,2′,5,5′-CB concentrations; the aerobic treatments did not modify the PCB mixture. In both types of systems, no variation of the total PCB concentration could be observed. Conclusions  This study showed that saturated hydrocarbon removal efficiency was nearly insensitive to the environmental factors investigated. The molecule structure and the dissolved oxygen concentration were the most affecting factors the removal efficiency of PAHs. PCB degradation under anaerobic conditions could be related to the pH values measured during the tests. Evaluation of results suggested that the abatement of pollutants investigated was not limited by a high salinity. High concentrations of dissolved metals and macronutrient addition did not influence the removal efficiency. Recommendations and Outlook. The slurry phase biological treatment of contaminated sediments could be applied whenever moderate removal efficiencies were required for remediation from saturated hydrocarbons and PAHs within a few days; further studies should be performed to improve the PCB abatement. Aerobic conditions should be maintained for the biodegradation of polyaromatic compounds; seawater or lagoon water could be used in the system.     

Methods for Extracting Heavy Metals in Soils from the Southwestern Amazon,Brazil

There are significant concerns about the impact of heavy metal contamination in soils as a consequence of urbanisation and industrialisation in developing countries. Routine chemical analysis of soils is used to measure the total concentration of metals from point source or diffuse activities, but this fails to put in context the bioavailability of the analyte or the potential toxicity of multiple contaminants. Bacterial biosensors provide a useful tool for assessing the toxicity of the bioavailable fraction of heavy metals in soils and for complementing chemical analysis. There are few examples of genuine environmental applications of biosensors for pollutant diagnosis. This study applied constitutively marked biosensors (which were comprehensively characterised) to soils collected from across Northern China (60,000 km²). The biosensors were responsive to soils impacted by As, Cd, Cr, Cu, Hg, Pb, and Zn when compared to ‘uncontaminated controls’. The response of the biosensor correlated with individual (or groups of) metals related to their concentration and source. The geo-accumulation index (I _geo) assisted in explaining the biosensor response. The constitutively marked biosensors offered a focussed understanding of analyte bioavailability and placed in a relevant context the elemental analysis. When matrix-matched control samples can be collected, then such a biosensor procedure (as adopted here) is applicable to contrasting soils exposed to a wide range of contaminants. Biosensor applications complemented routine soil chemical analysis for this regional-scale study.     

Lab-scale feasibility tests for sediment treatment using different physico-chemical techniques

Purpose  

The fairly high amounts of sediments dredged in coastal or internal water bodies for navigational and/or environmental purposes claims for the identification of appropriate management strategies. Dredged sediments are frequently affected by organic and inorganic contamination, so that their reuse, as an alternative to final landfill disposal, could need remediation. In this framework, a two-year joint research project was carried out to assess the feasibility of different remediation technologies for the treatment of polluted sediments.