Fermentation enhances the biological activity of Allium cepa bulb extracts

In this study, we compared the analytical fingerprint and bioactivity of three onion extracts, including an aqueous, a methanol, and a fermented aqueous extract. The extracts were characterized by HPLC-DAD, LC-MS, and GC-MS analyses. The antibacterial, antigenotoxic, and antiproliferative activity of these extracts was assessed by means of agar disk diffusion, bacterial growth kinetics, a comet assay, cell cycle distribution analysis, and cell viability testing. Both the aqueous and methanolic extracts showed a typical flavonol-fingerprint as assessed by HPLC measurements and showed little to no bioactivity. The fermented aqueous extract, which lacks the usual onion flavonoid profile, was found to be the most active in all of the assays. This finding indicates that metabolites of onion compounds, generated by lactic acid fermentation, may be more active than their precursor substances.     

Protein profiling of urine from dogs with renal disease using ProteinChip analysis.

Measurement of total urinary proteins in individuals that tested positive by urinary dipstick is a typical method for assessing the presence of potentially serious renal disorders. In the absence of such overt proteinuria, however, measurement of specific urinary proteins may be useful in the diagnosis of nephropathies and may provide greater insight into the pathogenesis. The urine of 28 dogs (16 with renal disease and 12 healthy) was evaluated to determine whether specific low-molecular-weight proteins or the pattern of protein excretion could also be used as a marker of tubular dysfunction in dogs. Specific proteins were assessed by immunological methods, whereas protein profiles were determined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (MS). In particular, changes in the excretion of retinol-binding protein (RBP) and Tamm-Horsfall protein (THP) appear to be of clinical relevance in the diagnosis of canine kidney diseases. The pattern of urinary protein and peptides revealed specific changes in abundance in dogs with renal disease at molecular masses (kD) of 11.58, 12.41, 12.60, 14.58, 20.95 (RBP), 27.85, and 65.69 (albumin). In conclusion, comparable proteins as in humans might be used as urinary markers for proximal (RBP) and distal (THP) tubular dysfunction in dogs. Surface-enhanced laser desorption/ionization time-of-flight MS is a promising tool for the study of kidney physiology and pathophysiology and might aid in the discovery of new biomarkers of renal disease.     

Effects of chronic renal disease on the transport of vitamin A in plasma and urine of dogs

OBJECTIVE: To determine plasma and urine concentrations of retinol, retinyl esters, retinol-binding protein (RBP), and Tamm-Horsfall protein (THP) in dogs with chronic renal disease (CRD). ANIMALS: 17 dogs with naturally developing CRD and 21 healthy control dogs. PROCEDURE: A diagnosis of CRD was established on the basis of clinical signs, plasma concentrations of creatinine and urea, and results of urinalysis. Concentrations of retinol and retinyl esters were measured by use of reverse-phase high-performance liquid chromatography. Concentrations of RBP and THP were measured by use of sensitive ELISA systems. RESULTS: Dogs with CRD had higher plasma concentrations of retinol, which were not paralleled by differences in plasma concentrations of RBP. Calculated ratio of urinary total vitamin A (sum of concentrations of retinol and retinyl esters to creatinine concentration) and ratio of the concentration of urinary retinyl esters to creatinine concentration did not differ between groups. However, we detected a significantly higher retinol-to-creatinine ratio in the urine of dogs with CRD, which was paralleled by a higher urinary RBP-to-creatinine ratio. Thus, in dogs with CRD, the estimated fractional clearance of total vitamin A, retinol, and RBP was increased. Furthermore, dogs with CRD had a reduced urinary THP-to-creatinine ratio. CONCLUSIONS AND CLINICAL RELEVANCE: Results of this study documented that CRD affects the concentrations of retinol in plasma and urine of dogs. Analysis of the data indicates that measurement of urinary RBP and urinary THP concentrations provides valuable information that can be helpful in follow-up monitoring of dogs with CRD.     

Release of C and N from roots of peas and oats and their availability to soil microorganisms

Nutrient mobilisation in the rhizosphere is driven by soil microorganisms and controlled by the release of available C compounds from roots. It is not known how the quality of release influences this process in situ. Therefore, the present study was conducted to investigate the amount and turnover of rhizodeposition, in this study defined as root-derived C or N present in the soil after removal of roots and root fragments, released at different growth stages of peas (Pisum sativum L.) and oats (Avena sativa L.). Plants were grown in soil columns placed in a raised bed under outdoor conditions and simultaneously pulse labelled in situ with a ¹³C-glucose-¹⁵N-urea solution using a stem feeding method. After harvest, ¹³C and ¹⁵N was recovered in plant parts and soil pools, including the microbial biomass. Net rhizodeposition of C and N as a percentage of total plant C and N was higher in peas than in oats. Moreover, the C-to-N ratio of the rhizodeposits was lower in peas, and a higher proportion of the microbial biomass and inorganic N was derived from rhizodeposition. These results suggest a positive plant-soil feedback shaping nutrient mobilisation. This process is driven by the C and N supply of roots, which has a higher availability in peas than in oats.     

Stem labeling results in different patterns of 14C rhizorespiration and 15N distribution in plants compared to natural assimilation pathways

To investigate C and N rhizodeposition, plants can be ¹³C‐¹⁵N double‐labeled with glucose and urea using a stem‐feeding method (wick method). However, it is unclear how the ¹³C applied as glucose is released into the soil as rhizorespiration in comparison with the ¹³C applied as CO₂ using a natural uptake pathway. In the present study, we therefore compared the short‐term fate of ¹⁴C and ¹⁵N in white lupine and pea plants applied either by the wick method or the natural pathways of C and N assimilation. Plants were pulse‐labeled in ¹⁴CO₂‐enriched atmosphere and ¹⁵N urea was applied to the roots (atmosphere–soil) following the natural assimilation pathways, or plants were simultaneously labeled with ¹⁴C and ¹⁵N by applying a ¹⁴C glucose–¹⁵N urea solution into the stem using the wick method. Plant development, soil microbial biomass, total rhizorespiration, and distribution of N in plants were not affected by the labeling method used but by plant species. However, the ¹⁵N : N ratio in plant parts was significantly (p < 0.05) affected by the labeling method, indicating more homogeneous ¹⁵N enrichment of plants labeled via root uptake. After ¹⁴CO₂ atmosphere labeling of plants, the cumulated ¹⁴CO₂ release from roots and soil showed the common saturation dynamics. In contrast, after ¹⁴C‐glucose labeling by the wick method, the cumulated ¹⁴CO₂ release increased linearly. These results show that ¹⁴C applied as glucose using the wick method is not rapidly transferred to the roots as compared to a short‐term ¹⁴CO₂ pulse. This is partly due to a slower ¹⁴C uptake and partly due to slow distribution within the plant. Consequently, ¹⁴C‐glucose application by the wick method is no pulse‐labeling approach. However, the advantages of the wick method for ¹³C‐¹⁵N double labeling for estimating rhizodeposition especially under field conditions requires further methodological research.     

Bacterial Community Composition and Genes for Herbicide Degradation in a Stormwater Wetland Collecting Herbicide Runoff

Stormwater wetlands collect and attenuate runoff-related herbicides, limiting their transport into aquatic ecosystems. Knowledge on wetland bacterial communities with respect to herbicide dissipation is scarce. Previous studies showed that hydrological and hydrochemical conditions, including pesticide removal capacity, may change from spring to summer in stormwater wetlands. We hypothesized that these changes alter bacterial communities, which, in turn, influence pesticide degradation capacities in stormwater wetland. Here, we report on bacterial community changes in a stormwater wetland exposed to pesticide runoff, and the occurrence of trz, atz, puh, and phn genes potentially involved in the biodegradation of simazine, diuron, and glyphosate. Based on T-RFLP analysis of amplified 16S rRNA genes, a response of bacterial communities to pesticide exposure was not detected. Changes in stormwater wetland bacterial community mainly followed seasonal variations in the wetland. Hydrological and hydrochemical fluctuations and vegetation development in the wetland presumably contributed to prevent detection of effects of pesticide exposure on overall bacterial community. End point PCR assays for trz, atz, phn, and puh genes associated with herbicide degradation were positive for several environmental samples, which suggest that microbial degradation contributes to pesticide dissipation. However, a correlation of corresponding genes with herbicide concentrations could not be detected. Overall, this study represents a first step to identify changes in bacterial community associated with the presence of pesticides and their degradation in stormwater wetland.     

Drought effects on C,N, and P nutrition and the antioxidative system of beech seedlings depend on geographic origin

In future, prolonged summer drought and heat will constitute a major risk for the cultivation of shallow‐rooting beech in Central Europe and will negatively affect the productivity of beech forests. In a pot experiment under controlled conditions, the influence of long‐term (28 d) water deprivation on nitrogen (N), carbon (C), phosphate (P_i), and ascorbate (ASC) concentrations was examined in leaves and fine roots of beech seedlings (Fagus sylvatica L.) from six provenances originating from Central Europe (Germany: Neidenstein and Illertissen, intermediate habitats), the Balkan peninsula (Croatia: Zagreb and Gospic, wet habitats), and Southeast Europe (Bulgaria: Kotel, Greece: Paikos; dry habitats). The goal of the study was to identify beech provenances well adapted to water limitation during summer drought events. Our results suggest that N might be involved in the alleviation of water scarcity, whereas P_i might become a limiting factor for forest growth during drought periods. Drought stress resulted in significant changes of ASC pools in leaves and fine roots and the ASC redox state. Under well‐watered and under drought conditions, ASC in leaves was the most important factor causing differences between the provenances examined. Finally, a link between P nutrition and the capacity of antioxidative stress defense by ascorbate could be highlighted. Based on observations from this study, beech seedlings from three origins (Paikos, Zagreb, and Neidenstein) might constitute beech provenances well adapted to water shortage in summer. This conclusion is drawn from the high potential of these provenances to alleviate oxidative stress during water shortage.