Élelmiszerek mirohullámú dielektromos jellemzőinek vizsgálata és alkalmazása a technológiai fejlesztésben és minőségbiztosításban = Research of microwave dielectric properties of foods, their use in technological development and in the quality assurance

A kutatás első fázisában üregrezonátoros és csőtápvonalas mérőrendszereket fejlesztettünk ki élelmiszerek dielektromos jellemzőinek vizsgálata céljából. Mérési és számítási eredményeink alapján algoritmust állítottunk fel, amellyel gyorsan és egyszerűen tudjuk megbecsülni különböző nedvességtartalmú és halmazsűrűségű gabonák dielektromos állandóját. Tej és sör mikrohullámú pasztőrözése céljából folyamatos üzemű laboratóriumi hőkezelő berendezést fejlesztettünk ki. A folyamatos üzemet a mikrohullámú készülékbe helyezett üveg-spirál segítségével alakítottuk ki. A technikai jellemzők vizsgálatán túl mikrobiológiai vizsgálatot is végeztünk hőkezelt tej és sörmintákon. A vizsgálatok eredményeként megállapítható, hogy a spirálcsöves mikrohullámú hőkezelő berendezés alkalmas pasztőrözésre. A kutatómunka keretében kisérletet tettünk palackozott sör mikrohullámú hőkezelésére alkalmas folyamatosüzemű berendezés kifejlesztésére.A kifejlesztett változat a megengedhetőnél nagyobb háttér sugárzást okoz,ezért továbbfejlesztése szükséges. A kutatás befejező fázisában tojáslé mikrohullámú pasztőrözésével kapcsolatos vizsgálatokba kezdtünk, ezek eredménye és további fejlesztése folyamatban van. | A measuring system with a resonant cavity and with a rectangular waveguide was set up to investigate the dielectric properties of food products. Based on the results of the measurements and calculations an algorithm was set up, which makes possible the quick and simple estimation of the complex permittivity of wheat samples of different moisture content and bulk density. A laboratory pasteurizations device was developed for the continuous microwave heat treatment of milk and beer. Continuous operation was achieved by putting glass spiral insets in the oven. In addition to the measurement of physical attributes some microbiological examinations were also carried out on the pasteurized milk and beer samples. The results of the investigations show that the microwave heat treatment device with spiral pipes is suitable for pasteurization. In the framework of this research an attempt was made to set up a continuously operating device that is suitable for the microwave heat treatment of bottled beer. However the background radiation of the device exceeds occupational safety limits, thus it is not appropriate for investigations in its current form. In the final stages of this research some investigations were carried out related to the microwave pasteurization of liquid eggs. The determination of results and the further development of the method is still underway

Neofabraea kienholzii, a novel causal agent of grapevine trunk diseases in Hungary

Recently, more and more new fungal pathogens have been described as causal agents of grapevine trunk diseases (GTDs), which lead to increasingly significant economic losses in viticulture worldwide. The genus Neofabraea consists of species mainly known as important plant pathogens causing perennial canker and bull’s eye rot, a common postharvest disease of apple (Malus domestica) and pear (Pyrus communis) fruits. Neofabraea kienholzii also causes lesions on pome fruits and canker on woody tissues, but its pathogenicity has not been demonstrated on grapevine yet. In 2015, two strains, identified as N. kienholzii based on ITS sequence data, were isolated from vines showing symptoms of GTDs in Hungary. For an unambiguous taxonomic placement of the isolates, four loci (ITS, LSU, TUB2 and RPB2) were amplified and sequenced. The phylogenetic analysis confirmed that the two isolates represent N. kienholzii. Pathogenicity tests performed on potted grapevines, shoots, and canes confirmed the virulence of these fungi. Their growth and sporulation on different media were also investigated. To the best of our knowledge, this is the first proof of N. kienholzii might cause symptoms on Vitis and might have a role in GTDs

Improved DNA extraction and quantitative real-time PCR for genotyping Erysiphe necator and detecting the DMI fungicide resistance marker A495T, using single ascocarps

DNA extraction from minute fungal samples is challenging in all genetic studies. Identification of genetic groups and population biology mostly rely on the laborious production of single conidium isolates or on field samples, including infected plant materials. This paper reports a simple and cost-effective protocol for DNA extraction from individual chasmothecia of Erysiphe necator for subsequent applications. It is a less laborious alternative for genotyping purposes than production and analysis of single conidium isolates or analysis of infected plant material from the field. Using the protocols described here for 186 E. necator samples tested, genetic groups A and B were assigned. Based on CYP51 sequences, all the samples belonged to group B, while TUB2 sequences exhibited SNPs also diagnostic for group A. Additionally, a quantitative real-time PCR detection method of single nucleotide polymorphism in the CYP51 gene associated with DMI fungicide resistance was applied. The A495T marker, associated with DMI resistance, and here reported for the first time from Hungary, was detected by quantitative real-time PCR assays and direct sequencing of CYP51. The methods developed in this study can be applied as routine tests to monitor powdery mildew populations for fungicide resistance and other genetic characteristics

The fungus Kalmusia longispora is able to cause vascular necrosis on Vitis vinifera

Fungal diseases in agronomically important plants such as grapevines result in significantly reduced production, pecuniary losses, and increased use of environmentally damaging chemicals. Beside the well-known diseases, there is an increased interest in wood-colonizing fungal pathogens that infect the woody tissues of grapevines. In 2015, a traditional isolation method was performed on grapevine trunks showing symptoms of trunk diseases in Hungary. One isolate (T15142) was identified as Kalmusia longispora (formerly Dendrothyrium longisporum) according to morphological and phylogenetic analyses. To evaluate the pathogenicity of this fungus on grapevines, artificial infections were carried out under greenhouse and field conditions, including the CBS 824.84 and ex-type CBS 582.83 strains. All isolates could be re-isolated from inoculated plants; however, varying virulence was observed among them in terms of the vascular necrosis caused. The incidence and severity of this symptom seemed to be congruent with the laccase-producing capabilities of the isolates. This is the first report on the ability of Kalmusia longispora to cause symptoms on grapevines, and on its possible dependence on laccase secretion

Protective Effects of Pituitary Adenylate-Cyclase-Activating Polypeptide on Retinal Vasculature and Molecular Responses in a Rat Model of Moderate Glaucoma

Despite the high probability of glaucoma-related blindness, its cause is not fully understood and there is no efficient therapeutic strategy for neuroprotection. Vascular factors have been suggested to play an important role in glaucoma development and progression. Previously, we have proven the neuroprotective effects of pituitary adenylate-cyclase-activating polypeptide (PACAP) eye drops in an inducible, microbeads model in rats that is able to reproduce many clinically relevant features of human glaucoma. In the present study, we examined the potential protective effects of PACAP1-38 on the retinal vasculature and the molecular changes in hypoxia. Ocular hypertension was induced by injection of microbeads into the anterior chamber, while control rats received PBS. PACAP dissolved in vehicle (1 µg/drop) or vehicle treatment was started one day after the injections for four weeks three times a day. Retinal degeneration was assessed with optical coherence tomography (OCT), and vascular and molecular changes were assessed by immunofluorescence labeling. HIF1-α and VEGF-A protein levels were measured by Western blot. OCT images proved severe retinal degeneration in the glaucomatous group, while PACAP1-38 eye drops had a retinoprotective effect. Vascular parameters were deteriorated and molecular analysis suggested hypoxic conditions in glaucoma. PACAP treatment exerted a positive effect against these alterations. In summary, PACAP could prevent the severe damage to the retina and its vasculature induced by ocular hypertension in a microbeads model

Redox and Hormonal Changes in the Transcriptome of Grape (Vitis vinifera) Berries During Natural Noble Rot Development

Noble rot is a favorable form of the interaction between grape (Vitis spp.) berries and the phytopathogenic fungus Botrytis cinerea. The transcriptome pattern of grapevine cells subject to natural noble rot development in the historic Hungarian Tokaj wine region has not been previously published. Furmint, a traditional white Tokaj variety suited to develop great quality noble rot was used in the experiments. Exploring a subset of the Furmint transcriptome redox and hormonal changes distinguishing between noble rot and bunch rot was revealed. Noble rot is defined by an early spike in abscisic acid (ABA) accumulation and a pronounced remodeling of ABA-related gene expression. Transcription of glutathione S-transferase isoforms is uniquely upregulated, whereas gene expression of some sectors of the antioxidative apparatus (e.g., catalases, carotenoid biosynthesis) is downregulated. These mRNA responses are lacking in berries exposed to bunch rot. Our results help to explain molecular details behind the fine and dynamic balance between noble rot and bunch rot development

Protective Effects of Pituitary Adenylate-Cyclase-Activating Polypeptide on Retinal Vasculature and Molecular Responses in a Rat Model of Moderate Glaucoma

Despite the high probability of glaucoma-related blindness, its cause is not fully understood and there is no efficient therapeutic strategy for neuroprotection. Vascular factors have been suggested to play an important role in glaucoma development and progression. Previously, we have proven the neuroprotective effects of pituitary adenylate-cyclase-activating polypeptide (PACAP) eye drops in an inducible, microbeads model in rats that is able to reproduce many clinically relevant features of human glaucoma. In the present study, we examined the potential protective effects of PACAP1-38 on the retinal vasculature and the molecular changes in hypoxia. Ocular hypertension was induced by injection of microbeads into the anterior chamber, while control rats received PBS. PACAP dissolved in vehicle (1 µg/drop) or vehicle treatment was started one day after the injections for four weeks three times a day. Retinal degeneration was assessed with optical coherence tomography (OCT), and vascular and molecular changes were assessed by immunofluorescence labeling. HIF1-α and VEGF-A protein levels were measured by Western blot. OCT images proved severe retinal degeneration in the glaucomatous group, while PACAP1-38 eye drops had a retinoprotective effect. Vascular parameters were deteriorated and molecular analysis suggested hypoxic conditions in glaucoma. PACAP treatment exerted a positive effect against these alterations. In summary, PACAP could prevent the severe damage to the retina and its vasculature induced by ocular hypertension in a microbeads model

Above-ground parts of white grapevine Vitis vinifera cv. Furmint share core members of the fungal microbiome

Grapevine (Vitis vinifera) is a reservoir of fungal endophytes that may affect its growth, health status and grape production. Although there is growing interest in comparing fungal communities of mainly red grape varieties across various factors using only high-throughput sequencing, the small-scale mycobiome variations in geographically close vineyards need further examination. We aimed to characterize the fungal microbiome of the above-ground tissues of V. vinifera cv. Furmint in different plant parts, seasons and sites using culture-dependent and culture-independent methods, and in planta fluorescent microscopic visualization techniques. Samples were collected from four sites of the Tokaj wine region in Mad and two reference sites in Eger, � Hungary, across different seasons for 2 years. Fungal endophytes of young and mature leaves, flowers and grape bunches were collected at different phenological stages. Based on each technique, Aureobasidium pullulans, Cladosporium spp. and the complex species Alternaria alternata dominated the community at every site, season and plant organ. We found no significant difference among communities in distinct neighbouring vineyards, nor when compared with the distant reference sites. We can conclude that the different shoot parts of the Furmint grapevines harbour a common core group of fungal community in these regions

Retinoprotective Effects of PACAP Eye Drops in Microbead-Induced Glaucoma Model in Rats

Glaucoma is associated with increased intraocular pressure (IOP), causing the apoptosis of retinal ganglion cells (RGCs) and the loss of their axons leading to blindness. Pituitary adenylate cyclase activating polypeptide (PACAP) is neuroprotective in several neural injuries, including retinopathies. The aim of this study was to investigate the effects of PACAP1-38 eye drops in a model of glaucoma. IOP was elevated bilaterally by injections of microbeads to block the aqueous humor outflow. The control groups received the same volume of saline. Animals were treated with PACAP1-38 (1 µg/drop, 3 × 1 drop/day) or vehicle for 4 weeks starting one day after the injections. Retinal morphology by histology and optical coherence tomography, function by electroretinography, and IOP changes were analyzed. Animals were sacrificed 8 weeks after the injections. Microbeads injections induced a significant increase in the IOP, while PACAP1-38 treatment lowered it to normal levels (~10 mmHg). Significant retinal degeneration and functional impairment were observed in the microbead-injected group without PACAP1-38 treatment. In the microbeads + PACAP1-38 group, the retinal morphology and functionality were close to the normal values. In summary, our results show that PACAP1-38, given in form of eye drops, is neuroprotective in glaucoma, providing the basis for potential future therapeutic administration

Untargeted metabolomic analyses support the main phylogenetic groups of the common plant-associated Alternaria fungi isolated from grapevine (Vitis vinifera)

Alternaria, a cosmopolitan fungal genus is a dominant member of the grapevine (Vitis vinifera) microbiome. Several Alternaria species are known to produce a variety of secondary metabolites, which are particularly relevant to plant protection and food safety in field crops. According to previous findings, the majority of Alternaria species inhabiting grapevine belong to Alternaria sect. Alternaria. However, the phylogenetic diversity and secondary metabolite production of the distinct Alternaria species has remained unclear. In this study, our aim was to examine the genetic and metabolic diversity of endophytic Alternaria isolates associated with the above-ground tissues of the grapevine. Altogether, 270 Alternaria isolates were collected from asymptomatic leaves and grape clusters of different grapevine varieties in the Eger wine region of Hungary. After analyses of the nuclear ribosomal DNA internal transcribed spacer (ITS) and RNA polymerase second largest subunit (rpb2) sequences, 170 isolates were chosen for further analyses. Sequences of the Alternaria major allergen gene (Alt a 1), endopolygalacturonase (endoPG), OPA10-2, and KOG1058 were also included in the phylogenetic analyses. Identification of secondary metabolites and metabolite profiling of the isolates were performed using high-performance liquid chromatography (HPLC)–high-resolution tandem mass spectrometry (HR-MS/MS). The multilocus phylogeny results revealed two distinct groups in grapevine, namely A. alternata and the A. arborescens species complex (AASC). Eight main metabolites were identified in all collected Alternaria isolates, regardless of their affiliation to the species and lineages. Multivariate analyses of untargeted metabolites found no clear separations; however, a partial least squares-discriminant analysis model was able to successfully discriminate between the metabolic datasets from isolates belonging to the AASC and A. alternata. By conducting univariate analysis based on the discriminant ability of the metabolites, we also identified several features exhibiting large and significant variation between A. alternata and the AASC. The separation of these groups may suggest functional differences, which may also play a role in the functioning of the plant microbiome