Bioremediation of diesel oil in a co-contaminated soil by bioaugmentation with a microbial formula tailored with native strains selected for heavy metals resistance

The aim of the work is to assess the feasibility of bioremediation of a soil, containing heavy metals and spiked with diesel oil (DO), through a bioaugmentation strategy based on the use of a microbial formula tailored with selected native strains. The soil originated from the metallurgic area of Bagnoli (Naples, Italy). The formula, named ENEA-LAM, combines ten bacterial strains selected for multiple resistance to heavy metals among the native microbial community. The biodegradation process of diesel oil was assessed in biometer flasks by monitoring the following parameters: DO composition by GC-MS, CO₂ evolution rate, microbial load and composition of the community by T-RFLP, physiological profile in Biolog® ECOplates and ecotoxicity of the system. The application of this microbial formula allowed to obtain, in the presence of heavy metals, the complete degradation of n-C_12-20, the total disappearance of phenantrene, a 60% reduction of isoprenoids and an overall reduction of about 75% of the total diesel hydrocarbons in 42 days. Concurrently with the increase of metabolic activity at community level and the microbial load, the gradual abatement of the ecotoxicity was observed. The T-RFLP analysis highlighted that most of the ENEA-LAM strains survived and some minor native strains, undetectable in the soil at the beginning of the experiment, developed. Such a bioaugmentation approach allows the newly established microbial community to strike a balance between the introduced and the naturally present microorganisms. The results indicate that the use of a tailored microbial formula may efficiently facilitate and speed up the bioremediation of matrices co-contaminated with hydrocarbons and heavy metals. The study represents the first step for the scale up of the system and should be verified at a larger scale. In this view, this bioaugmentation strategy may contribute to overcome a critical bottleneck of the bioremediation technology.     

A ferromagnetic linear trinuclear Ni(II)-Schiff base complex supported by phenoxo and cinnamato bridges

A new linear trinuclear nickel(II) complex, [Ni₃(salme)₂(OCn)₄] (Hsalme = 2-[(3-methylamino-propylimino)-methyl]-phenol, OCn = cinnamate), showing weak ferromagnetic coupling (J = 1.8(1) cm⁻¹) through phenoxo and a novel tridentate bridging mode (1κ²OO′:2κO′) of the cinnamate ligand has been synthesized and structurally characterized by X-ray crystallography.     

A wide range kinetic modeling study of pyrolysis and oxidation of methyl butanoate and methyl decanoate – Note II: Lumped kinetic model of decomposition and combustion of methyl esters up to methyl decanoate

The aim of this work is to develop and discuss a lumped kinetic model to simulate the pyrolysis and combustion behavior of methyl decanoate. Validation of the lumped kinetic model of methyl decanoate in a very wide range of conditions, with temperature ranging from 500 to more than 2000 K, pressures up to 16 bar and equivalent ratios from lean to pyrolysis conditions, proved that, despite the drastic simplifications, the model can properly reproduce the experimental measurements in pyrolysis as well as in an oxidation environment, in both the low temperature regime and in flame conditions. This model is an extension of the lumped model of methyl butanoate developed and discussed in the first part of this work [1]. Thus, the lumped kinetic model of methyl butanoate and methyl decanoate is also quite simply applied to simulating the combustion behavior of intermediate methyl esters, by using the lever rule between the two reference components. The overall agreement with experimental measurements is very encouraging and lays the basis for the extension to the lumped kinetic scheme to soy and rapeseed biodiesel fuels.     

Influence of NaCl,Na2SO4 and O2 on power generation from microbial fuel cells with non-catalyzed carbon electrodes and natural inocula

Microbial fuel cells (MFCs) are facing several technological challenges before they can be considered as reliable energy sources. Although several feasible inocula, materials and catalysts have been employed to produce energy, the design of a MFC should be done under realistic conditions: abundant and economic feedstock. In this study, two different MFC designs (parallel plate and tank reactors) are tested with non-catalyzed carbon electrodes and natural inocula. In both approaches cathodic oxygen reduction is performed on two different non-catalyzed carbon materials: carbon fabric and reticulate vitreous carbon. This study shows that power and current densities can be boosted by systematically decreasing the catholyte resistance (by additions of NaCl or Na₂SO₄) and dissolved oxygen concentration. In the parallel plate cell configuration, a mixed culture coming from sludge wastewater was used and power outputs up to 73 mW m^?2 (2867 mW m^?3) coupled to 187 mA m^?2 (anode surface area), were achieved. In the Sediment MFC cell configuration, lagoon sediment was used as both organic source of energy and natural supply of bacteria. Under this approach, the concentration of the organic matter is limited but it is demonstrated that bacteria can be adapted to degrade acetate. Power outputs up to 3.9 mW m^?2 normalized to the anodic electrode footprint area, coupled to 13 mA m^?2 were achieved.     

Ammunition identification by means of the organic analysis of gunshot residues using Raman spectroscopy

The ability to unequivocally identify a gunshot residue (GSR) when a firearm is discharged is a very important and crucial part of crime scene investigation. To date, the great majority of the analyses have focused on the inorganic components of GSR, but the introduction of "lead-free" or "nontoxic" ammunitions makes it difficult to prevent false negatives. This study introduces a fast methodology for the organic analysis of GSR using Raman spectroscopy. Six different types of ammunition were fired at short distances into cloth targets, and the Raman spectra produced by the GSR were measured and compared with the spectra from the unfired gunpowder ammunition. The GSR spectrum shows high similarity to the spectrum of the unfired ammunition, allowing the GSR to be traced to the ammunition used. Additionally, other substances that might be found on the victim's, shooter's, or suspect's clothes and might be confused with GSR, such as sand, dried blood, or black ink from a common ballpoint pen, were analyzed to test the screening capability of the Raman technique. The results obtained evidenced that Raman spectroscopy is a useful screening tool when fast analysis is desired and that little sample preparation is required for the analysis of GSR evidence.     

Spark-plasma-sintering temperature dependence of structural and piezoelectric properties of BNT–BT<Subscript>0.08</Subscript> nanostructured ceramics

(Bi_0.5Na_0.5)TiO₃ doped with 8 mol% BaTiO₃ powder prepared by sol–gel was compacted and sintered by spark-plasma-sintering method. The influence of spark-plasma-sintering temperature on the densification and piezoelectric properties of these ceramics was studied. Starting from BNT–BT_0.08 powder gel with a microstructure consisting of particles with average size of 50 nm, ceramics with grain size of 60–90 nm and density of about 98.9–99.6% of the theoretical density were obtained by spark-plasma-sintering at 800–900 °C. Increasing the sintering temperature by SPS from 800 to 900 °C lead to the increase of d ₃₃, k _p, ε₃₃^T and, decrease of Q _m. Typical d ₃₃ and k _p values of BNT–BT_0.08 ceramics sintered by spark-plasma-sintering at 900 °C were 8 and 0.029, respectively.     

Occurrence of ochratoxin A in raw ham muscle,salami and dry-cured ham from pigs fed with contaminated diet

Pork meat-derived products can contribute to the overall ochratoxin A intake, either by carry-over effect, or by environmental mould population cross-contamination. In order to assess the role of these different contamination routes, a study was carried out with pigs challenged orally with OTA contaminated feed at subchronical level. After slaughtering, thighs and minced meat from control and treated groups were transformed into dry-cured hams and salami, respectively, which were analysed for OTA determination after ripening. From collected data, the carry-over in muscle was generally low, whereas a significant contribution to the OTA contamination in dry-cured hams was due to toxinogenic mould population growing on their surface during ripening. Finally, a survey of different types of dry-cured ham (n = 110), from the Italian market, was performed, showing the occurrence of OTA on the surface portion in 84 out of 110 samples with a median value of 0.53 μg/kg and in the inner core in 32 out of 110 samples with a median value lower than 0.1 μg/kg.     

Characterisation of the most odour-active compounds of bone tainted dry-cured Iberian ham

The most odour-active compounds of different bone tainted dry-cured Iberian hams were researched using the detection frequency method. Most of the odourants identified were found in all the Iberian hams (spoiled and unspoiled). Some compounds (ethyl butanoate, dimethyl disulfide, phenylacetaldehyde, acetic, propanoic, butanoic, 3-methylbutanoic and pentanoic acids) were identified in the spoiled hams as Iberian ham odourants for the first time. The detection frequency (DF) values for the spoiled and the unspoiled hams were markedly different. The main differences were found for 2-methylpropanal, ethyl-2-methylpropanoate, ethyl-2-methylbutanoate, phenylacetaldehyde and methional (the lowest DF values were found in the unspoiled ham) and hexanal (the largest DF value was found in the unspoiled ham). Spoiled hams with a different global odour had different DF values.     

Synthesis of cyclopropane fatty acids in Lactobacillus helveticus and Lactobacillus sanfranciscensis and their cellular fatty acids changes following short term acid and cold stresses

An implemented GC method to separate and quantify the cell cyclopropane fatty acids lactobacillic (C19cyc11) and dehydrosterculic (C19cyc9) was used to study the adaptive response to sublethal acid and cold stresses in Lactobacillus helveticus and Lactobacillus sanfranciscensis. The comparison of the composition of cellular fatty acids of the two strains and their changes after 2 h of stress exposure under micro-aerobic and anaerobic conditions indicated that the aerobic biosynthetic pathway for unsaturated fatty acids is prevalent in L. sanfranciscensis, while the anaerobic pathway is prevalent in L. helveticus. Indeed in the latter strain, in the presence of a source of oleic acid and under micro-aerobic conditions, C18:1n11 and its post-synthetic derivative C19cyc11 accounted for overall proportion ranging from 52 to 28% of the total FAs. On the other hand L. sanfranciscensis synthesizes by aerobic pathway C18:1n9 and transforms it to C19cyc9. However in this species the cumulative level of these two FAs did not exceed 30%. The relevant proportion of dodecanoic acid in the latter species suggests that carbon chain shortening is the principal strategy of L. sanfranciscensis to modulate fluidity or chemico-physical properties of the membranes.     

Carotenoid composition and vitamin A value in ají (Capsicum baccatum L.) and rocoto (C. pubescens R. & P.), 2 pepper species from the Andean region

The carotenoid patterns of fully ripe fruits from 12 Bolivian accessions of the Andean peppers Capsicum baccatum (ají) and C. pubescens (rocoto) were determined by high-performance liquid chromatography (HPLC)-photodiode array detector (PDA)-mass spectrometry (MS). We include 2 California Wonder cultivars as C. annuum controls. A total of 16 carotenoids were identified and differences among species were mostly found at the quantitative level. Among red-fruited genotypes, capsanthin was the main carotenoid in the 3 species (25% to 50% contribution to carotenoid fraction), although ajíes contained the lowest contribution of this carotenoid. In addition, the contribution of capsanthin 5,6-epoxide to total carotenoids in this species was high (11% to 27%) in comparison to rocotos and red C. annuum. Antheraxanthin and violaxanthin were, in general, the next most relevant carotenoids in the red Andean peppers (6.1% to 10.6%). Violaxanthin was the major carotenoid in yellow-/orange-fruited genotypes of the 3 species (37% to 68% total carotenoids), although yellow rocotos were characterized by lower levels (<45%). Cis-violaxanthin, antheraxanthin, and lutein were the next most relevant carotenoids in the yellow/orange Andean peppers (5% to 14%). As a whole, rocotos showed the highest contributions of provitamin A carotenoids to the carotenoid fraction. In terms of nutritional contribution, both ajíes and rocotos provide a remarkable provitamin A activity, with several accessions showing a content in retinol equivalents higher than California Wonder controls. Furthermore, levels of lutein in yellow/orange ajíes and rocotos were clearly higher than California Wonder pepper (≥1000 μg·100/g). Finally, the Andean peppers, particularly red ajíes, can be also considered as a noticeable source of capsanthin, the most powerful antioxidant compound among pepper carotenoids. Practical Application: Capsicum peppers are known for their content in carotenoids, although there is no information about 2 species with Andean origin: ajíes and rocotos. Due to their relevance for the Andean cuisine and increasing importance in ethnic restaurants in Europe, we studied their carotenoid pattern and vitamin A contribution.