The effect of extraction process on polyphenol content, triterpene composition and bioactivity of yellow birch (Betula alleghaniensis Britton) extracts

Crude ethanol extracts from different tissues of Betula alleghaniensis: wood, inner and outer bark, foliage, and twigs were evaluated for their nitric oxide (NO)-radical scavenging activities and inhibitory effects on the production of NO in LPS/INFγ-stimulated RAW 264.7 macrophages. As a renewed interest in plant-derived drugs has led to an increased need for efficient extraction methods, ultrasonic-assisted extraction (UAE) was investigated and compared with conventional maceration. The lower energy consumption by the UAE process compared to maceration determined in our study qualifies also this extraction as an environmentally friendly process. Our results indicate that the foliage extract has the most potent radical scavenging capacity while wood and twigs extracts exert the highest inhibitory effects on the production of NO in LPS/INFγ-stimulated RAW 264.7 macrophages. Extracts obtained by UAE present lower cytotoxic activity on RAW cells. Our results also demonstrate that ultrasounds help to selectively extract the bioactive molecules from foliage, twigs and wood, which inhibit the production of NO by macrophages. The highest total phenol content has been determined for the inner bark extracts and the flavonoids are the major phenolics present in foliage extracts. Poor correlations determined between the total phenols and radical scavenging capacity of the extracts indicates to the synergistic or antagonist effects of molecules present, various polyphenols and triterpenes being identified in the extracts studied in this research.     

Characterization of resistance to Globodera rostochiensis pathotype Ro1 in cultivated and wild potato species accessions from the Vavilov Institute of Plant Industry

Potato cyst nematodes (PCN) collected in six localities in the Leningrad region of North West Russia were identified as Globodera rostochiensis pathotype Ro1 and were used for subsequent resistance tests. Seventy‐nine accessions of cultivated and closely related wild potato species from the VIR collection in Russia were screened on resistance to G. rostochiensis pathotype Ro1 and on the presence of molecular markers for H1 and Gro1‐4 resistance genes. No associations were detected between the resistance level of diploid and tetraploid Andean and tetraploid Chilean potato landraces (indigenous cultivars) and their related wild species and their geographical distribution or presence of PCR‐based markers that are associated with the H1 and Gro1‐4 genes. At the same time, all susceptible genotypes lacked such markers. New sources of resistance were found and could be used in breeding.     

Prevalence and genotypes of Giardia duodenalis in dairy and beef cattle in farms around Charlottetown, Prince Edward Island, Canada

Prevalence of Giardia duodenalis in dairy and beef cattle on farms around Charlottetown, Prince Edward Island (Canada) was determined by analyzing feces using direct immunofluorescence antibody microscopy. Genotypes were determined by 16S-rRNA sequencing. Fecal samples (n = 892) were collected from adult cattle in dairy tie-stall, dairy free-stall, and beef herds (10 herds each), and from calves (n = 183) from 11 dairy farms. Prevalence rates were 38% and 51% in cows and calves, respectively. Giardia duodenalis was present in all dairy herds, in 9/10 beef herds and in calves from 10/11 herds examined. Prevalence rates were 40% and 41% for cows in tie- and free-stall herds, respectively, and 27% for beef cows. Zoonotic Assemblage A was found in 12.2% of calves concomitantly infected with Assemblage E. All successfully sequenced samples (114/128) from cows corresponded to Assemblage E. Giardia duodenalis is highly prevalent in cattle herds in Prince Edward Island and Assemblage A in calves is a potential public health concern.     

A Simple Flow-through System for Toxicity Testing with Daphnids

A simple and accurate flow-through system was developed for toxicity evaluation of biodegradable substances, wastewaters, and surface waters. The chronic toxicity of phenol to the daphnid Daphnia magna was studied during a 21 d exposure period, first using a semi-static and later a flow-through test. The flow- through system was advantageous especially when lower concentrations of phenol were examined. Its use provided a constant concentration of phenol in all tested samples. Exposure to phenol showed a similar influence on both survival and reproduction of daphnids; the IC25 value was 3.18 mg L-1.     

Detection of Potyviral Nuclear Inclusion b Proteins by Monoclonal Antibodies Raised to Synthetic Peptides

Potyviral nuclear inclusion b protein (NIb), the RNA-dependent RNA polymerase, contains three highly conserved regions. Peptides corresponding to these regions were synthesised and used for immunisation. A panel of monoclonal antibodies was obtained. Most of the MAbs reacted with the peptides and a recombinant NIb of PVY in PTA-ELISA. Two of them specifically detected native NIb of potato A, potato V, potato Y, plum pox and turnip mosaic potyviruses in extracts of infected plants in Western blots. Time course experiments revealed that NIb protein can be first detected on the fifth day after infection.     

Distribution of trichothecenes, zearalenone, and ergosterol in a fractionated wheat harvest lot

To investigate possible co-occurrences of type B trichothecenes and zearalenone within a Fusarium culmorum-infected wheat harvest lot, kernels were fractionated into six groups by visual criteria. The Fusarium-damaged kernels were subdivided into white, shrunken, and red kernel groups, and the remaining kernels were sorted into healthy, black spotted, and nonspecific groups. The distribution patterns of nivalenol, deoxynivalenol, zearalenone, and ergosterol were determined for possible correlations. Significant correlations between the distribution patterns were found for the mycotoxins and ergosterol for the grouped kernels (r = 0.997-0.999, p < 0.0001). Additionally, remarkably outstanding levels of nivalenol (24-fold more than the mean at 1.16 mg/kg), deoxynivalenol (27-fold more than the mean at 0.16 mg/kg), zearalenone (25-fold more than the mean at 77 microg/kg), and ergosterol (17-fold more than the mean at 13.4 mg/kg) were found in the red kernel group. Further, detailed mycotoxin and ergosterol analyses were carried out on various segments (kernel surface, conidia, bran, and flour) of the red kernels. However, the mycotoxin and ergosterol distribution profiles revealed nonsignificant correlations for these kernel segments, with the exception of deoxynivalenol and nivalenol, which were moderately correlated (r = 0.948, p = 0.035).     

Past and present potential of the Adriatic deep sea sediments to produce methane hydrates

Journal of Soils and Sediments - There is a growing understanding that methane hydrates (MHs) distributed globally in permafrost and deep sea sediments present an enormous unconventional reservoir...     

Characterisation of a 16SrII phytoplasma strain associated with bushy stunt of hawkweed oxtongue (Picris hieracioides) in south-eastern Serbia and the role of the leafhopper Neoaliturus fenestratus (Deltocephalinae) as a natural vector

A 2-year study of host association, molecular characterisation and vector transmission of a phytoplasma related to the 16SrII group in a vineyard of south-eastern Serbia was conducted. Grapevine, eight common weeds and 31 Auchenorrhyncha species were collected and analysed for phytoplasma presence. PCR-RFLP analyses of the 16S rRNA gene identified the presence of a new strain of phytoplasma related to the 16SrII group in P. hieracioides with symptoms of stunting or bushy stunting. Grapevine samples, all without symptoms, were negative for phytoplasma presence. Plants of Erigeron annuus, Cynodon dactylon, Daucus carota and P. hieracioides, either exhibiting symptoms of yellowing or without symptoms, were positive for the presence of stolbur phytoplasma. Among the tested cicada species, seven were infected with phytoplasmas from the aster yellows group, two with stolbur phytoplasma, two with 16SrII phytoplasma, and one with the 16SrV-C phytoplasma subgroup. The phytoplasma strain of the 16SrII group was recorded in approximately 50?% of the collected leafhopper species Neoaliturus fenestratus and in a few specimens of the planthopper Dictyophara europaea. The vector status of N. fenestratus was tested using the second generation of the planthopper in two separate transmission trials with P. hieracioides and periwinkle seedlings. In both tests, the leafhopper successfully transmitted 16SrII phytoplasma to exposed plants, proving its role as a natural vector of this phytoplasma in Europe. A finer molecular characterisation and phylogenetic relatedness of the 16SrII phytoplasma strain by sequence analyses of the 16S rRNA and ribosomal protein genes rpl22-rps3 indicated that it was most closely related to the 16SrII-E subgroup.     

A Qualitative Multi-Attribute Model for The Multifunctional Assessment of ��Streuobst Stands�� in NE Slovenia

Streuobst stands, i.e., tall fruit trees on vigorous rootstock on traditional grassland, represent an important source of raw material for the processing industry and for traditional fruit processing on family-run farms. Apart from production aspects, the high-stem orchards also play a role in the conservation of the traditional landscape, and indirectly in maintenance of the viability of rural areas. In this paper, a qualitative multi-attribute model for the assessment of Streuobst stands with respect to their multifunctional characteristics is presented. The assessment is based on four groups of attributes: (1) production criteria (percentage of missing trees), (2) biodiversity (fruit species and varieties, artificial human intervention), (3) landscape diversity (visual appearance, eco-diversity and erosion protection), and (4) function of the stand (row or individual trees, countryside appearance). The assessment is based on the aggregation of input attribute values to an overall assessment through user-defined decision rules. The model was applied to 85 sample stands in NE Slovenia. The assessment shows that most of the stands (48) were rated as ??very poor?? or ??poor??, mainly as a result of poor cultivation and lack of maintenance.     

Short-term evolution of hydration effects on soil organic matter properties and resulting implications for sorption of naphthalene-2-ol

Purpose

Sorption of xenobiotics in soils and especially to soil organic matter (SOM) determines their mobility and bioavailability in ecosystems. However, SOM as the major sorbent may be altered in its physicochemical properties upon changes in boundary conditions such as hydration. Hence, the goal of this study was to determine the influence of soil hydration on physicochemical properties of SOM and the resulting effects on sorption of xenobiotics.

Materials and methods

Samples of a Histosol with 51?% SOM were adjusted to five water contents from 10 to 75?% (w/w based on dry soil mass) and aged for water contact times of 0?weeks to 3?years. The hydrated samples were characterized with respect to thermal properties of SOM and of the incorporated water via differential scanning calorimetry and with respect to hydration-induced swelling via ¹H-NMR relaxometry, and the sessile drop method was applied to determine their soil?Cwater contact angle. Sorption kinetics and isotherms of naphthalene-2-ol in the pre-treated peat samples were determined in batch experiments.

Results and discussion

SOM matrix rigidity varied with the water content and increased with water contact time. An initial minimum in SOM rigidity at ~30?% water content became maximum after ~20?weeks, also resulting in the strongest resistance towards water infiltration. We argue that the anomalies at 30?% water content are related to the critical water content for the formation of freezable water w _crit in the peat samples, which was 26.2?±?0.3?%. Conditions for water-assisted molecular bridging were assumably optimal at 30?% water content. Whereas parameters of naphthalene-2-ol sorption reflecting the sorbed amount were mainly altered by the wetting properties of SOM, sorption linearity and hysteresis were influenced by the anomalies in peat matrix properties at a water content around 30?%.

Conclusions

The study revealed that the interplay of SOM and water led to highly variable and complex changes in SOM physicochemical properties. These properties may serve as a predictor for sorption of xenobiotics in soil at varying hydration conditions enabling a more precise assessment of the environmental fate of xenobiotics.