Highest Percentage Contribution Research Articles

Contribution of low molecular weight antioxidants to the antioxidant screen of germinated soybean seeds

Soybean seed of the Mazovia variety (Glycine max) were germinated in the dark at a constant temperature of 25°C up to 168 h (24 h × 7). Changes in content of low molecular weight antioxidants (LMWA) in the course of germination were studied. The analyzed compounds were: total phenolics, soluble proteins, tocopherols (α-T, β-T, γ -T, δ -T), reduced and oxidized glutathione, L-ascorbic acid and L-dehydroascorbic acid. The changes in total antioxidant status (TAS) and the peroxyl radical-trapping capacity (PRTC) of the processed seeds were measured and compared to those of the raw seeds. On the basis of data obtained, the contribution of LMWA to the TAS of raw and germinated soybean seeds was calculated. The results showed a very high molar percentage contribution of phenolic compounds (49.7%) in opposition to glutathione (7.0%), tocopherols (4.0%) and soluble protein (5.7%) to the total TAS of raw soybean seeds. The germination process led to the increased contribution of phenolic compounds (67.7%), soluble proteins (9.3%) and ascorbic acid (4.4%) to the total TAS of germinated seeds and as a result, a decrease in the antioxidant gap was observed compared to the total TAS of raw soybean seeds. This study showed that the contribution of experimentally obtained total PRTC to the total TAS of raw and germinated soybean seeds after seven days ofthe process was 48% and 25.2%, respectively. The PRTC results were comparable to those obtained in TAS only when calculation was done by multiple mean values for content of investigated compounds and their relative potency with respect to Trolox. The PRTC values obtained in this manner were higher than those obtained experimentally indicating that high molecular weight antioxidants as well as are able to quench peroxyl radicals as well as low molecular weight antioxidants. Therefore, calculation of PRTC is a more accurate method that eliminates the puzzling question of unidentified antioxidants shown as the antioxidant gap in the TAS assay.

Rates of Mitochondrial and Peroxisomal β-Oxidation of Palmitate Change during Postnatal Development and Food Deprivation in Liver, Kidney and Heart of Pigs , ,

We measured total, mitochondrial and peroxisomal capacities for β-oxidation of [1-14C]palmitate in homogenates of liver, kidney and heart from pigs within 0.5 h after birth (0 h, unfed) and at 24 h (suckled or unfed), 10 d (suckled or 24-h food-deprived), 21 d (suckled or 24-h food-deprived) and 5 mo (overnight food-deprived) of age. Assays were conducted in the absence (total β-oxidation) or presence (peroxisomal β-oxidation) of antimycin A and rotenone. Mitochondrial β-oxidation was calculated as total minus peroxisomal β-oxidation. Acid-soluble products (ASP) from incubation of tissue homogenates from 24-h-old unfed pigs with [1-14C]palmitate were analyzed by radio-HPLC. Total and mitochondrial β-oxidation capacities were greater (P < 0.05) at 24 h after birth in liver, and at 10 d in kidney and heart, than at 0 or 24 h. Peroxisomal β-oxidation capacity was increased (P < 0.05) at 24 h after birth in liver and at 10 and 21 d in heart; in kidney, the capacity was higher during the preweaning period than in adults. Across ages, peroxisomal β-oxidation capacity represented 37 to 51%, 28 to 41%, and 26 to 31% of total β-oxidation capacity in liver, kidney, and heart, respectively. Food deprivation increased hepatic total β-oxidation at 10 d and decreased peroxisomal β-oxidation at 24 h but had no effect in kidney and heart. Regardless of the presence of respiratory inhibitors, 32%, 31 to 40%, and 45 to 50% of palmitate carboxyl carbon in acid-soluble products was accumulated in acetate in liver, kidney, and heart, respectively. We suggest that a high percentage contribution of peroxisomal β-oxidation may act as a compensatory mechanism for piglets to oxidize milk fatty acids during postnatal development. Furthermore, acetogenesis may be an important fate of acetyl-CoA from β-oxidation of fatty acids in various piglet tissues.

Osmolality and electrolyte concentration of hemolymph and the problem of ion and volume regulation of cells in higher insects

1. 1. The study was carried out on 22 species of insects from 5 orders. The osmolality of their hemolymph varied from 319 to 421 mOsm/kg H 2O, concentration of Na + 4.6 to 118 mM/l, K + 6.3 to 73mM/l, Ca 2+ 3.6 to 12.9 mM/l, Mg 2+ 2.3 to 76 mM/l. The most abundant cation in the hemolymph of insects from higher orders is either K + or Mg 2+. 2. 2. In the muscles of lower and higher insects K + is usually within 80–120 mM/kg wet wt. 3. 3. Most Ca 2+ and Mg 2+ in hemolymph is bound with protein and low molecular anions, concentration of free Ca 2+ is 0.9-2.1mM/l Mg 2+ 3.7–8.0 mM/l. 4. 4. It is concluded that, in insects, potassium hemolymph, cell volume regulation and accumulation of ions in the cell, are ensured by an increased osmolality of hemolymph due to a high percentage contribution of low molecular organic substances which are retained in the hemolymph due to the absence of filtration apparatus in the Malpighian tubules.

The case of the Itata estuary (Bio-Bio Region-Chile) plant formations: anthropogenic interference or natural disturbance-induced diversity enrichment?

The current study examined the relationship between native and introduced plant species, as indicators of the state of anthropogenic influence on plant formations in the area of the Itata estuary (Bío-Bío Region, Chile). A total of 186 vegetation samples were collected in different plant communities in the wetlands and adjacent areas of the Itata River during 2011 and 2012. The communities of four terrestrial plant formations were sampled within dunes, prairies, shrub lands and food crops, and within two aquatic habitats (freshwater and salt marsh). The total flora comprised of 222 species, these were dominated by introduced taxa with thirty-three species considered invasive for Chile. The high percentage contribution of these alien weeds to the total community could be interpreted as signs of a strong degree of anthropogenic interference in the natural plant formations. However, some habitats such as salt marshes are subjected to periodic natural disturbances (e.g. tsunamis), lacking human interference. Consequently, in some habitats, alien species, which are more resilient, represent the primary plant formations.

Mechanisms Involved in Soil Aggregate Stabilization by Fungi and Bacteria

AbstractMicrobial mechanisms of soil aggregate stabilization were investigated as a function of microbiological and water‐stability changes of incubated artificial aggregates, 2 to 4.76 mm. in size composed of soil particles &lt; 0.5 mm., prepared from Waupun silt loam. Aggregate water‐stability was determined by wet‐sieving and expressed as the percentage of soil material bound into water‐stable aggregates 0.5 to 1 mm., 1 to 2 mm. and &gt; 2 mm. in size. Microbial development was investigated by dilution plate and microscopic methods.Aggregate stabilization was a function more of microbial synthesis of soil‐binding substances than of numbers of microorganisms. Extensive production of mycelium and spores in soil aggregates by a fungus known to be capable of aggregate stabilization, did not, necessarily, result in an increase in the stability of the aggregates. Stabilization of aggregates by Mucor silvaticus involved the binding of soil particles into &gt; 2 mm. water‐stable aggregates at all stages of incubation. Aggregates stabilized under anaerobic conditions exhibited a high percentage contribution of 0.5‐ to 1‐mm. and 1‐ to 2‐mm. aggregates to total stability in the early stages of incubation. A relatively high proportion of the total water‐stability of sucrose‐amended aggregates possessing the indigenous mixed microflora was attributable to stable 0.5‐ to 2‐mm. aggregates in the early stages of aerobic incubation, an indication that bacteria were more important than fungi in the initial stabilization of these aggregates.