Fusarium genetic traceability: Role for mycotoxin control in small grain cereals agro-food chains

Risks associated with mycotoxin contamination of cereals, that are included in the ten major staple foods and greatly contribute to the dietary energy intake, are of worldwide relevance. In small grain cereals, mycotoxins are produced by fungi such as Aspergillus, Penicillium, Alternaria and Fusarium that colonize the plant in the field and can grow during the post-harvest period, producing several classes of mycotoxins. The identification of mycotoxigenic fungal species and strains is essential for developing effective strategies for control. For this purpose, genetic traceability has proved to be a valuable tool that can be applied along the whole production chain, starting in the field for early diagnosis of FHB (Fusarium Head Blight) disease to the final processing steps, such as malting or pasta making. In this paper, DNA-based analytical tools that are currently available for the identification and quantification of mycotoxigenic fungal species and strains are reviewed, with particular emphasis on Fusarium, and their possible applications in mycotoxin control in small grain cereal chains are discussed.     

Antibacterial efficacy of polypyrrole in textile applications

This paper describes application and evaluation of polypyrrole as an antibacterial polymer. Polypyrrole was produced embedding two doping agents: chloride and dicyclohexyl sulfosuccinate ions. Stability of the antibacterial efficacy of polypyrrole deposited on cotton fabrics was assessed before and after three different kinds of washing (namely, laundering with anionic and non-ionic detergents and dry-cleaning). Polypyrrole showed excellent antibacterial properties (100 % of bacterial reduction) against Escherichia coli for both doping agents. Treated fabrics were further characterised by scanning electron microscopy, energy dispersive X-ray analysis and infrared spectroscopy. The antibacterial efficacy diminished after launderings with anionic and non-ionic detergents because of two different mechanisms: the neutralisation of positive charges under alkali conditions (dedoping), and a partial removal of polypyrrole by abrasion and surfactant action. After dry-cleaning, polypyrrole embedding chloride and dicyclohexyl sulfosuccinate ions still showed excellent antibacterial efficacy. Moreover, scanning electron microscopy investigations were used to intuitively explain the bactericidal mechanism of polypyrrole on Escherichia coli bacteria.     

Effect of maturity stage at harvest on the ensilability of maize hybrids in the early and late FAO classes,grown in areas differing in yield potential

The aim of this study was to assess the effects of earliness (according to FAO class), maturity stage at harvest and environmental conditions on the ensilability of maize hybrids described by their fermentation products and by a fermentation quality index (FQI). Maize hybrids belonging to early (n = 14) and late (n = 15) FAO classes were grown in low, medium and high potential yield areas and harvested at an early (EH), medium (MH) and late maturity stage (LH), that is, at 1/3, 2/3 and 5 d after the 2/3 milk line stage, respectively, according to a split‐plot design. Upon harvest, each sample (n = 522) was analysed for dry matter (DM) and water‐soluble carbohydrates (WSC) before being ensiled in vacuum‐packed bags (n = 1,044). After 60 days of conservation, samples were analysed for DM and fermentation products. In the pre‐ensiling phase, DM was higher in early hybrids (p = .001), low yield areas (p < .001) and at LH maturity (p < .001), whereas WSC contents were higher in early hybrids (p < .001), medium yield areas (p < .001) and at EH maturity (p < .001). With regard to silages, early hybrids had a higher FQI (p < .001), which was highest in areas with a high yield potential (p < .01) and at EH maturity (p < .01). Late hybrids proved to be better suited for low yield areas compared with early hybrids (p < .01) and had a higher FQI at EH and MH than at LH maturity (p < .01).     

A recombinant flagellin fragment,which includes the epitopes flg22 and flgII-28, provides a useful tool to study flagellin-triggered immunity

Plants and animals independently evolved the ability to recognize flagellin (also called FliC), the building block of the bacterial flagellum, as part of their innate immune response. While animals recognize a relatively large region of FliC, most plants recognize one or two short epitopes of FliC: flg22 and flgII-28. However, since most research in plants has focused on flg22 and flgII-28 and not the actual FliC protein, the importance of any FliC region beyond the two epitopes in plant immunity is poorly understood. Here we report cloning, overexpression, and purification of a Pseudomonas syringae FliC fragment from amino acid 1 to 143, which includes both FliC epitopes and the adjacent alpha helices. Exposing Arabidopsis thaliana leaves to FliC_1–143 did not reveal any additional FliC recognition capabilities beyond flg22. However, while the kiwifruit species Actinidia arguta did not respond to either flg22 or flgII-28, treatment of A. arguta leaves with FliC_1–143 triggered a significant reactive oxygen response, indicating recognition. This result suggests that in some plant species, recognition of FliC requires regions of FliC beyond the two well-known epitopes and that FliC_1–143 represents a useful tool in the study of plant immunity.     

Natural antimicrobials in spray-dried microparticles based on cellulose derivatives as potential eco-compatible agrochemicals

Journal of Plant Diseases and Protection - It has been demonstrated that some aromatic substances synthesized by plants serve as plant defense mechanisms. However, natural extracts are difficult to...     

An innovative stabilization/solidification treatment For contaminated soil remediation: demonstration project results

Background, aim, and scope

An innovative stabilization/solidification (S/S) process using high-performance additivated concrete technology was developed for remediating soil contaminated by metals from abandoned industrial sites. In order to verify the effectiveness of this new ex situ S/S procedure, an area highly contaminated by metallic pollutants (As, Cd, Hg, and Pb), due to the uncontrolled discharge of waste generated from artistic glass production on the island of Murano (Venice, Italy), was selected as a case study. The technique transforms the contaminated soil into an aggregate material suitable for reuse as on-site backfill. This paper reports the main results of the demonstration project performed in collaboration with the local environmental protection agency (ARPAV).

Materials and methods

An ex situ treatment for brownfield remediation, based on the transformation of contaminated soil into very dense, low porous, and mechanically resistant granular material, was set up and tested. Specific additives (water reducers and superplasticizers) to improve the stabilized material properties were developed and patented. A demonstration plant assembled on the study area to treat 6 m³ h^–1was then tested. After excavation, the contaminated soil was screened to remove coarse material. The fraction Ø?>?4 mm (coarse fraction), mainly composed of glass, brick, concrete, and stone debris, was directly reused on site after passing through a washing treatment section. The highly polluted fraction Ø?≤?4 mm (fine fraction) was treated in the S/S treatment division of the plant (European patent WO/2006/097272). The fine fraction was mixed with Portland cement and additives defined on the basis of the high performance concrete technique. the mixture was then granulated in a rolling-plate system. After 28 days curing in an onsite storage area to allow for cement hydration, the stabilized material was monitored before its in situ relocation. The chemical, mechanical, and ecotoxicological reliability and performance of the treatment was checked. Metal leachability was verified according to four leaching test methods: Italian Environmental Ministry Decree (1998), EN 12457 (2002) tout court, amended only with MgSO₄ and, lastly, with artificial sea water. The mechanical properties were measured according to BS (1990) and AASHTO (1999) to obtain the Aggregate Crushing Value and California Bearing Ratio, in that order. Moreover, leachate samples prepared with artificial seawater were assessed via the Crassostrea gigas embryotoxicity test and Vibrio fischeri bioluminescence inhibition test to discriminate the presence of potential ecotoxicological effects for the brackish and saltwater biota.

Results

Outcomes from all leachate samples highlighted the effectiveness of the remediation treatment, fully complying with the Italian legislation for non-hazardous material reuse under a physicochemical viewpoint. The stabilized granular material demonstrated high mechanical strength, low porosity, and leachability. Moreover, ecotoxicological surveys indicated the presence of low toxicity levels in leachate samples according to both toxicity tests.

Discussion

Remediated soil samples revealed a significant decrease in leachability of heavy metals as a consequence of the application of additivated cement that enhanced granular material properties, resulting in improved compactness due to the reduction in water content. The toxicity data confirmed this state-of-the-art technique, indicating that leachates could be deemed as minor acutely toxic.

Conclusions

The proposed S/S treatment proved to be able to remediate soil contaminated by heavy metals through trapping pollutants in pellet materials presenting adequate physicochemical, mechanical, and ecotoxicological properties in order to prevent leachability phenomena, their reclamation, and reuse being made easier by its granular form.

Recommendation and perspectives

This project foresees long-term monitoring activity over several years (until 2014) to consider treatment durability.