Laboratory tests on the biocontrol of chestnut insect pests on Etna (Sicily, Italy) by means of entomopathogenic nematodes

The virulence of seventeen strains of entomopathogenic nematodes, belonging to four species of Steinernema and two of Heterorhabditis, against the chestnut insect parasites Curculio elephas, C. glandium, Pammene castanicola, Cydia splendana and C. fagiglandana, was tested in laboratory. The bioassays were conducted on the insect larvae collected in three different years (2010-2012) in chestnut groves of Etna. Most of the strains tested resulted good biocontrol agents for all the treated insect pests. The strains S. feltiae ESA and S. feltiae EPP were the most effective strains autochthonous of Etna when all the species of insect pests are considered as a whole

The complex and multiform relationship between Nematoda and Bacteria

The relationship between nematodes and bacteria has taken place in different ways, from the simple trophic relation to the most sophisticated forms of symbiosis. Such symbiosis is not a primitive condition but it appeared and was established, being advantageous, during the evolution of different nematode taxa, independently and with different, sometimes complex, modalities ranging from mutualism to parasitism. The most significant modalities of mutualism are exposed here with particular stress on the highly specific relationship between entomopathogenic nematodes of the families Heterorhabditidae and Steinernematidae and their symbionts. This relationship, fruit of co-evolution between the nematodes and their bacteria, is treated from different points of view and at the light of the most recent genetic research

ENDOSYMBIONTS OF ENTOMOPATHOGENIC NEMATODES FROM SOUTH ITALY:A PHENOTYPIC STUDY

We examined different Xenorhabdusstrains (five of X. bovieniiand two of X. kozodoii), obtained from EPNisolates belonging to the genus Steinernema(S. feltiae, S. ichnusae, S. apuliae, S. vulcanicum) of different geographicorigin by both genotypic and phenotypic analysis. Common laboratory assays were done for traits such as antibioticresistance, haemolytic activity, lactose utilisation, biofilm production, chosen as the least selectable traits for EPN life-cycle, and thus as (presumably) neutral traits. As selective marker, the activity of the endosymbiont’s toxins was verified inan in vivoassay on G. mellonellalarvae. Genotyping done by 16S partial sequencing was used for identification purposes.Xenorhabdusbovieniiisolates showed a broad phenotypic spectrum; on the other hand, X. kozodoiishowed a less degreeof phenotypic variation, reduced ability of biofilm production and conspicuous β-galactosidase activity. However, all thestrains were able to kill G. mellonellalarvae with high efficiency

Cerebellar degeneration-related protein 1 expression in fibroblasts of patients affected by down syndrome

Down syndrome (DS) is the most common genetic cause of intellectual disability, resulting from lack of disjunction of sister chromatids of human chromosome 21 or not partial disjunction of chromoso..

Effect of the surface morphology of TiO2 nanotubes on photocatalytic efficacy using electron-transfer-based assays and antimicrobial tests

The application of titanium oxide nanotubes for the removal of contaminants from freshwater is a rapidly growing scientific interest, especially when it comes to water conservation strategies. In this study we employed four different titanium oxide nanotube surfaces, prepared by a two-electrode anodic oxidation. Two of the surfaces were synthesised in aqueous media, while the other two surfaces were synthesised in ethylene glycol. One of the arrays synthesised in the organic medium was impregnated with silver nanoparticles, while the remaining surfaces were not. The chemical reactivity of the various surfaces was assessed using 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,20 -azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) as free electron sensitive probe molecules, in parallel with tannic acid degradation and copper ion reducing capacity. The potential antimicrobial activity of the surfaces was assessed against a panel of microorganisms composed of yeast, fungi, Gram-positive and Gram-negative bacteria. Field emission scanning electron microscopy revealed that surfaces produced in the aqueous medium had a smaller tube length and a smaller tube diameter. It was noted that one of the materials using sodium sulfate as the supporting electrolyte had the most irregular nanostructure morphology with tubes growing to the side rather than vertically. The structural variation of the surfaces directly reflected both the chemical and biological activity, with the nanotubes formed in ethylene glycol showing the fastest rates in the stabilization of DPPH and ABTS radicals, the fastest tannic acid decomposition under various pH conditions and the fastest metal reducing activity. Furthermore, the surface containing silver and its bare counterpart showed the most effectivepeer-reviewe

Suitability of different titanium dioxide nanotube morphologies for photocatalytic water treatment

Photocatalysis has long been touted as one of the most promising technologies for environmental remediation. The ability of photocatalysts to degrade a host of different pollutants, especially recalcitrant molecules, is certainly appealing. Titanium dioxide (TiO2) has been used extensively for this purpose. Anodic oxidation allows for the synthesis of a highly ordered nanotubular structure with a high degree of tunability. In this study, a series of TiO2 arrays were synthesised using different electrolytes and different potentials. Mixed anatase-rutile photocatalysts with excellent wettability were achieved with all the experimental iterations. Under UVA light, all the materials showed significant photoactivity towards different organic pollutants. The nanotubes synthesised in the ethylene glycol-based electrolyte exhibited the best performance, with near complete degradation of all the pollutants. The antibacterial activity of this same material was similarly high, with extremely low bacterial survival rates. Increasing the voltage resulted in wider and longer nanotubes, characteristics which increase the level of photocatalytic activity. The ease of synthesis coupled with the excellent activity makes this a viable material that can be used in flat-plate reactors and that is suitable for photocatalytic water treatment.peer-reviewe

Ag/ZnO/PMMA nanocomposites for efficient water reuse

This work attempts to produce photocatalytic surfaces for large-scale applications by depositing nanostructured coatings on polymeric substrates. ZnO/poly(methyl methacrylate) (PMMA) composites were prepared by low-temperature atomic layer deposition (ALD) of ZnO on PMMA substrates. In addition, to increase the photocatalytic and antibacterial activities of ZnO films, Ag nanoparticles were added on ZnO surfaces using plasma-enhanced ALD. The morphology, crystallinity, and chemical composition of the specimens were meticulously examined by scanning and transmission electron microscopies, energy-dispersive X-ray spectroscopy, and X-ray diffraction analyses. The noteworthy photocatalytic activity of the nanocomposites was proved by the degradation of the following organic pollutants in aqueous solution: methylene blue, paracetamol, and sodium lauryl sulfate. The antibacterial properties of the samples were tested using Escherichia coli as a model organism. Moreover, the possible toxic effects of the specimens were checked by biological tests. The present results unambiguously indicate the Ag/ZnO/PMMA nanocomposite as a powerful tool for an advanced wastewater treatment technology.peer-reviewe