Inactivation of Viruses and Bacteriophages as Models for Swine Hepatitis E Virus in Food Matrices

Hepatitis E virus has been recognised as a food-borne virus hazard in pork products, due to its zoonotic properties. This risk can be reduced by adequate treatment of the food to inactivate food-borne viruses. We used a spectrum of viruses and bacteriophages to evaluate the effect of three food treatments: high pressure processing (HPP), lactic acid (LA) and intense light pulse (ILP) treatments. On swine liver at 400 MPa for 10 min, HPP gave log₁₀ reductions of ≥4.2, ≥5.0 and 3.4 for feline calicivirus (FCV) 2280, FCV wildtype (wt) and murine norovirus 1 (MNV 1), respectively. Escherichia coli coliphage ?X174 displayed a lower reduction of 1.1, while Escherichia coli coliphage MS2 was unaffected. For ham at 600 MPa, the corresponding reductions were 4.1, 4.4, 2.9, 1.7 and 1.3 log₁₀. LA treatment at 2.2 M gave log₁₀ reductions in the viral spectrum of 0.29–2.1 for swine liver and 0.87–3.1 for ham, with ?X174 and MNV 1, respectively, as the most stable microorganisms. The ILP treatment gave log₁₀ reductions of 1.6–2.8 for swine liver, 0.97–2.2 for ham and 1.3–2.3 for sausage, at 15–60 J cm^?2, with MS2 as the most stable microorganism. The HPP treatment gave significantly (p < 0.05) greater virus reduction on swine liver than ham for the viruses at equivalent pressure/time combinations. For ILP treatment, reductions on swine liver were significantly (p < 0.05) greater than on ham for all microorganisms. The results presented here could be used in assessments of different strategies to protect consumers against virus contamination and in advice to food producers. Conservative model indicators for the pathogenic viruses could be suggested.     

Rapid and Sensitive Detection of Lymphocystis Disease Virus Genotype VII by Loop-Mediated Isothermal Amplification

Lymphocystis disease virus (LCDV) infections have been described in gilthead seabream (Sparus aurata L.) and Senegalese sole (Solea senegalensis, Kaup), two of the most important marine fish species in the Mediterranean aquaculture. In this study, a rapid, specific, and sensitive detection method for LCDV genotype VII based on loop-mediated isothermal amplification (LAMP) was developed. The LAMP assay, performed using an apparatus with real-time amplification monitoring, was able to specifically detect LCDV genotype VII from clinically positive samples in less than 12 min. In addition, the assay allowed the detection of LCDV in all asymptomatic carrier fish analysed, identified by qPCR, showing an analytical sensitivity of ten copies of viral DNA per reaction. The LCDV LAMP assay has proven to be a promising diagnostic method that can be used easily in fish farms to detect the presence and spread of this iridovirus.     

Removal of natural organic matter by cationic hydrogel with magnetic properties

Magnetic cationic hydrogel (MCH) was synthesized, and its removal efficiency and mechanisms in regard to natural organic matter (NOM, represented by humic acid and fulvic acid) from the aqueous environment were studied. The effects of time, adsorbent dosage, initial pH, ionic strength, background ions, and NOM types were also investigated. MCH was characterized and found to have a strong magnetic character, yielding an extra advantage for recycling and reuse. Batch studies showed that the removal of Aldrich humic acid (AHA) by MCH was effective. The main mechanism for the removal of NOM is believed to be due to electrostatic interaction. NOM with larger molecular weight tended to be preferentially removed. Solutions with low pH, high ionic strength, and background electrolytes containing calcium, sulfate and bicarbonate were unfavorable for AHA removal. The adsorption-desorption of MCH was evaluated in three cycles, and demonstrated high regeneration rates.     

Levels of antibiotic resistance genes in manure, biosolids, and fertilized soil

Increasing antibiotic resistance genes in the environment may pose a threat to public health. In this study, tetracycline and sulfonamide resistance genes (Tet-W, Tet-O, and Sul-I) were quantified in 24 manure samples from three farms and 18 biosolids samples from seven different wastewater treatment plants using quantitative polymerase chain reaction methods. Concentrations of Tet-W and Tet-O genes were observed to be significantly higher (p < 0.05) in manure than in biosolids samples. The background soil samples showed significantly lower concentration of the above genes compared with manure and biosolids. Lime-stabilized biosolids showed significantly (p < 0.05) lower concentration of antibiotic resistance genes compared with other biosolids treatment methods. Elevated levels of antibiotic resistance genes (Tet-W, Tet-O, and Sul-I) were observed in the amended soil samples after the land application of manure or biosolids (Site A) monitored for a period of about 4 mo. However, at another site (Site B), no significant increase (p > 0.05) in concentration of antibiotic resistance genes was observed after biosolids application on soil. Even though the concentration of antibiotic resistance genes in manure was statistically higher than that in biosolids, when they were applied on land, the contribution to the soil depended on the background soil concentration and the soil characteristics. Further study of multiple soil samples in various locations is needed.     

The Duero Diatom Index (DDI) for river water quality assessment in NW Spain: design and validation

Diatom indices developed in certain geographic regions are frequently used elsewhere, despite the strong evidence that such metrics are less useful when applied in regions other than that where species–environment relationships were originally assessed, showing that species have particular autoecological requirements in different geographic areas. The goal of this study was to develop a new metric, the Duero Diatom Index (DDI), aimed at monitoring water quality in Duero basin watercourses (NW Spain). In summer 2008 and 2009, a total of 355 epilithic diatom samples were collected following standard protocols. The 2008 samples were used to develop the DDI, whereas the samples collected during 2009 were used in the index testing. Weighted averages method was used to derive the autoecological profiles of diatoms with respect to pH, conductivity, biological oxygen demand, ammonia, nitrates, and phosphates. The optimum and tolerance values for the measured environmental variables were determined for 137 taxa with abundances and frequencies of occurrence above 1 %, and subsequent trophic indicator and sensitivity values were defined for the DDI. The correlation between the observed and the diatom-inferred nutrient concentrations was highest for phosphates (ρ _S?=?0.72). Significant statistical relationship were observed between DDI values and the chemistry-based General Quality Index values (p?=?0.006) and the specific pollution index (SPI) diatom metric (p?=?0.04). DDI has demonstrated a better correlation with water chemistry than SPI diatom metric.     

Trace elemental characterization of fly ash

The purpose of this study was to determine heavy metal concentrations in ash samples taken from the filter of the gas cleaning system of biomass incinerators in Austria. Knowing the concentrations of heavy metals is important for the decision of further treatment or utilization of the ashes. The heavy metals contained in the ashes remain in the bottom ash of the incinerator or leave the incinerator with the off-gas and are collected in the off-gas filter. The amount of the metals in the collected fly ash depends on the composition of the input material. The aim of this study was to examine this influence and compare the results with literature data. For measurement, the fly ash samples were at first dissolved in a microwave digestion unit using nitric acid and hydrochloric acid. Afterwards, 20 metals were analyzed by inductively coupled plasma optical emission spectrometry. Al, Fe, Mg, Mn, and Zn were found in higher concentrations in the fly ash samples. The enrichment factor between the concentrations in the fly ash and the concentrations in the input material was on average in the range of 18.     

Thermoplasticized Pectin by Extrusion/Thermo-Compression for Film Industrial Application

Journal of Polymers and the Environment - Researches for the development of materials with less environmental impact have been more common. Pectin is a natural polysaccharide, presenting in plants...     

Sorption of arsenic from soil-washing leachate by surfactant-modified zeolite

Post-treatment of leachate from soil-washing remedial actions may be necessary depending on the amounts of dissolved contaminants present. Uptake of arsenic species by surfactant-modified zeolite (SMZ) from a synthetic soil leachate (pH of approximately 12 [NaOH]) was measured as a test of SMZ as a post-treatment sorbent. Batch sorption isotherms were prepared using leachate to SMZ ratios from 40:1 to 4:1, and temperatures of 25 and 15 degrees C. Equilibrium levels of dissolved and total solution arsenic were similar. At each temperature, sorption appeared to reach a plateau or maximum, then decreased at the highest solution concentration, corresponding to the lowest amount of zeolite added (2.5 g). A maximum sorption value of 72.0 mmol of arsenic per kg of SMZ (5400 mg/kg) was observed at 25 degrees C, and 42.1 mmol/kg (3150 mg/kg) at 15 degrees C. Total arsenic recoveries varied from 74 to 125%. Surfactant-modified zeolite removed up to 97% of dissolved organic carbon and decolorized the leachate solutions. Excluding the points for the highest arsenic to SMZ ratio, the sorption isotherms were well described by the linearized form of the Langmuir equation, with coefficients of determination greater than 0.90 at both temperatures. Sorption of arsenic by SMZ is attributed to anion exchange with counterions on the surfactant head groups, and/or partitioning of organic carbon-complexed arsenic into the surfactant bilayer.