136 research outputs found

    Polymorphism of mycotoxin biosynthetic genes among Fusarium equiseti isolates from Italy and Poland

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    Fusarium equiseti (Corda) Saccardo is a soil saprophyte and a weak pathogen, associated with several diseases of fruit and other crops in subtropical and tropical areas, but also in countries with temperate climate. A wide range of secondary metabolites has been identified among natural F. equiseti populations, with zearalenone (ZEA), fusarochromanone and fusarenon-X being the most common. In present study, the genetic diversity of strains from two populations (from Italy and Poland) was evaluated by analysing the translation elongation factor 1α (tef-1α) sequences, two polyketide synthases from the ZEA biosynthetic pathway (PKS13 and PKS4) and the TRI5 gene from the trichothecene biosynthetic pathway. ZEA was produced in rice cultures by 20 of the 27 tested isolates in concentrations ranging from 1.34 ng/g to 34,000 ng/g). The ability to produce enniatins and trichothecenes was evaluated in all strains by identifying esyn1, TRI13 and TRI4 genes. The presence of PKS4 and PKS13 genes was confirmed by polymerase chain reaction (PCR) in only some ZEA-producing isolates. Similarly, the TRI5 gene was found in 14 of the 27 isolates tested. This is likely to have been caused by the divergence of those genes between F. equiseti and F. graminearum (the latter species was used for the primers design) and can be exploited in phylogenetic studies. The analysis of the mycotoxin biosynthetic gene sequences can be used to differentiate the studied genotypes even more precisely than the analysis of the non-coding regions (like tef-1α)

    Genetic and phenotypic variation of Fusarium proliferatum isolates from different host species

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    Fusarium proliferatum (Matsushima) Nirenberg is a common pathogen infecting numerous crop plants and occurring in various climatic zones. It produces large amounts of fumonisins, a group of polyketide-derived mycotoxins. Fumonisin biosynthesis is determined by the presence and activity of the FUM cluster, several co-regulated genes with a common expression pattern. In the present work, we analyzed 38 F. proliferatum isolates from different host plant species, demonstrating host-specific polymorphisms in partial sequences of the key FUM1 gene (encoding polyketide synthase). We also studied growth rates across different temperatures and sample origin and tried to establish the relationships between DNA sequence polymorphism and toxigenic potential. Phylogenetic analysis was conducted based on FUM1 and tef-1α sequences for all isolates. The results indicated the greatest variations of both toxigenic potential and growth patterns found across the wide selection of isolates derived from maize. Fumonisin production for maize isolates ranged from 3.74 to 4,500 μg/g of fumonisin B1. The most efficient producer isolates obtained from other host plants were only able to synthesize 1,820–2,419 μg/g of this metabolite. A weak negative rank correlation between fumonisin content and isolate growth rates was observed. All garlic-derived isolates formed a distinct group on a FUM1-based dendrogram. A second clade consisted of tropical and sub-tropical strains (isolated from pineapple and date palm). Interestingly, isolates with the fastest growth patterns were also grouped together and included both isolates originating from rice. The sequence of the FUM1 gene was found to be useful in revealing the intraspecific polymorphism, which is, to some extent, specifically correlated with the host plant

    APPLICATION OF WATERLOO MAPLE 9.5 AND WOLFRAM MATHEMATICA 5.1 SOFTWARE FOR ANALYTIC SOLVING OF CERTAIN NONLINEAR PARTIAL DIFFERENTIAL EQUATIONS OF PHYSICS

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    In the current paper some applications of the packet MAPLE (v. 9.5) for analytic solving ofcertain nonline partial differential equations have been presented. Additionally, for graphicpresentation of the found solutions packet MATHEMATICA (v. 5.1) has been applied

    Patogene plijesni u sjemenkama različitih sorti graška u Poljskoj

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    Legume crops are exposed to infection by fungal pathogens, which often results in contamination with mycotoxins. The aim of this study was to evaluate the level of field resistance/susceptibility of edible and fodder pea cultivars to the colonization of seeds by fungal pathogens in two subsequent seasons, as well as to identify the pathogens present in the seeds of the tested cultivars. Alternaria spp. were the most common fungi isolated from pea seeds in both seasons, followed by Fusarium spp., Stemphylium spp., Ulocladium spp., Botrytis cinerea Pers., Epicoccum nigrum Link., and Phoma pinodella L. K. Jones. The highest percentage of infected seeds (55 %) was recorded for cultivar Ezop. The presence of a large number of fungi was found in 2012 for cultivars Santana, Tarchalska, Medal, Cysterski, Mentor, Lasso, and Ezop. Fodder cultivars displayed a lower infection level than edible cultivars. We can conclude that Alternaria spp. were the most frequent fungi present in pea seeds in Poland and Fusarium spp. were likely the most dangerous, having in mind their established mycotoxigenic abilities.Cilj ovoga istraživanja bio je procijeniti stupanj otpornosti/podložnosti jestivih sorti graška i onih koji se koriste za krmivo na kolonizaciju sjemenki patogenim plijesnima tijekom dviju sezona te identificirati patogene u sjemenkama istraživanih sorti. Najčešća plijesan izdvojena iz sjemenki tijekom obiju sezona bila je Alternaria spp., a nju su brojnošću pratile Fusarium spp., Stemphylium spp., Ulocladium spp., Botrytis cinerea Pers., Epicoccum nigrum Link. i Phoma pinodella L. K. Jones. Najviši postotak zaraženih sjemenki (55 %) zabilježen je za sortu Ezop. Prisutnost većeg broja plijesni pronađen je 2012. u sortama Santana, Tarchalska, Medal, Cysterski, Mentor, Lasso i Ezop. Sorte korištene za krmivo pokazale su općenito nižu razinu zaraženosti od jestivih. Možemo zaključiti kako je Alternaria spp. bila najčešća plijesan u sjemenkama graška u Poljskoj, a Fusarium spp. vjerojatno najopasnija, uzimajući u obzir njene ustanovljene mikotoksigenične sposobnosti

    Modeling non-linear rheology of PLLA: comparison of Giesekus and Rolie-Poly constitutive models

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    Rheological models for biobased plastics can assist in predicting optimum processing parameters in industrial forming processes for biobased plastics and their composites such as film blowing, or injection stretch-blow molding in the packaging industry. Mathematical descriptions of polymer behavior during these forming processes are challenging, as they involve highly nonlinear, time-, temperature-, and strain-dependent physical deformation processes in the material, and have not been sufficiently tested against experimental data in those regimes. Therefore, the predictive capability of two polymer models, a classical Giesekus and a physically-based Rolie-Poly, is compared here for extensional and shear rheology data obtained on a poly(L-lactide) (PLLA) across a wide range of strain rates of relevance to those forming processes. Generally, elongational and shear melt flow behavior of PLLA was predicted to a satisfactory degree by both models across a wide range of strain rates (for strain rates 0.05–10.0 s−1), within the strain window up to 1.0. Both models show a better predictive capability for smaller strain rates, and no significant differences between their predictions were found. Hence, as the Giesekus model generally needs a smaller number of parameters, this class of models is more attractive when considering their use in computationally demanding forming simulations of biobased thermoplastics

    Prevalence and antibiotic resistance of Enterococcus strains isolated from poultry

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    The aim of this study was to evaluate the frequency of occurrence of bacteria of the genus Enterococcus in poultry, to identify them by means of matrixassisted laser desorption/ionisation time-of-flight mass spectrometry (MALDITOF MS), and to analyse the antimicrobial susceptibility of the isolated strains to the drugs most frequently used in poultry. The material for the bacteriological tests was obtained mainly from the heart (97%) of the birds investigated. Of a total of 2,970 samples tested, 911 (30.7%) tested positive for Enterococcus spp. Enterococci were detected in broilers (88.1%), laying hens (5.3%), turkeys (3.9%), breeding hens (2.2%), and geese (0.4%). The most commonly identified species were Enterococcus (E.) faecalis (74.7%), E. faecium (10.1%), E. gallinarum (5.5%), E. hirae (4.6%), and E. cecorum (4.1%). The most frequent resistance properties were resistance to sulphamethoxazole/trimethoprim (88%), tylosin (71.4%), enrofloxacin (69.4%), doxycycline (67.3%), and lincomycin/spectinomycin (56.1%). Only one vancomycin-resistant Enterococcus, E. cecorum from a broiler, was found

    Time Motion Differences between Romanian and Polish High Level Young Soccer Players during 6 vs. 6 Small Sided Games as an Effect of Training Program

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    The purpose of this study was to present a time motion differences between Romanian and Polish young soccer players during 6 vs 6 small sided games. Young male football players from Schools of Sports Masters in Oradea (Romania) and Łódź (Poland) participated in the study. During the training session the players participated in four small-sided games 6 vs. 6 with goalkeepers (4 × 4 min, 3 min of active recovery). Heart rate responses and distance covered during small-sided games were compared. There were significant differences in the distance covered by both nationality players and age groups in reference to each intensity zone. Polish players coverd significantly longer distance compared with romanian soccer players. The results of motion abilities of young players from two countries with different training systems show that training programs can have a significant effect on adoptive abilities of the players

    Disorders in the CMG helicase complex increase the proliferative capacity and delay chronological aging of budding yeast

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    The replication of DNA requires specialized and intricate machinery. This machinery is known as a replisome and is highly evolutionarily conserved, from simple unicellular organisms such as yeast to human cells. The replisome comprises multiple protein complexes responsible for various steps in the replication process. One crucial component of the replisome is the Cdc45-MCM-GINS (CMG) helicase complex, which unwinds double-stranded DNA and coordinates the assembly and function of other replisome components, including DNA polymerases. The genes encoding the CMG helicase components are essential for initiating DNA replication. In this study, we aimed to investigate how the absence of one copy of the CMG complex genes in heterozygous Saccharomyces cerevisiae cells impacts the cells' physiology and aging. Our data revealed that these cells exhibited a significant reduction in transcript levels for the respective CMG helicase complex proteins, as well as disruptions in the cell cycle, extended doubling times, and alterations in their biochemical profile. Notably, this study provided the first demonstration that cells heterozygous for genes encoding subunits of the CMG helicase exhibited a significantly increased reproductive potential and delayed chronological aging. Additionally, we observed a noteworthy correlation between RNA and polysaccharide levels in yeast and their reproductive potential, as well as a correlation between fatty acid levels and cell doubling times. Our findings also shed new light on the potential utility of yeast in investigating potential therapeutic targets for cancer treatment

    Depletion of the Origin Recognition Complex Subunits Delays Aging in Budding Yeast

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    Precise DNA replication is pivotal for ensuring the accurate inheritance of genetic information. To avoid genetic instability, each DNA fragment needs to be amplified only once per cell cycle. DNA replication in eukaryotes starts with the binding of the origin recognition complex (ORC) to the origins of DNA replication. The genes encoding ORC subunits have been conserved across eukaryotic evolution and are essential for the initiation of DNA replication. In this study, we conducted an extensive physiological and aging-dependent analysis of heterozygous cells lacking one copy of ORC genes in the BY4743 background. Cells with only one copy of the ORC genes showed a significant decrease in the level of ORC mRNA, a delay in the G1 phase of the cell cycle, and an extended doubling time. Here, we also show that the reducing the levels of Orc1-6 proteins significantly extends both the budding and average chronological lifespans. Heterozygous ORC/orcΔ and wild-type diploid cells easily undergo haploidization during chronological aging. This ploidy shift might be related to nutrient starvation or the inability to survive under stress conditions. A Raman spectroscopy analysis helped us to strengthen the hypothesis of the importance of lipid metabolism and homeostasis in aging
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