Effects of Application of Organic and Inorganic Wastes for Restoration of Sulphur-Mine Soil

In situ remediation with waste material is an inexpensive method to reduce contaminant availability in polluted soil. The experiments were done to investigate the effects of possible in situ application of two different amendments: inorganic material (marble sludge) and organic material (horticultural waste compost) on chemical and biological properties of abandoned metalliferous mine wastes. The results show that the application of inorganic material raises the pH above neutrality and the combination of inorganic and organic material would produce the highest ratio of biological activity. The reductions of available Zn, Pb and As in lime, organic and lime/organic amendments were favoured by incubation time. However, available Cd content increased after 275?days of incubation, except the treatment with inorganic amendment. This work denoted that the application of lime with organic amendments has a better effect than the lime alone because the addition of both amendments improves both soil chemical and biological properties.     

Methyl jasmonate reduces chilling injury and maintains postharvest quality of mango fruit

Exposure of mango (Mangifera indica cv. Tommy Atkins) fruit to methyl jasmonate (MJ) vapors (10(-)(4) M) for 24 h at 25 degrees C reduced chilling injury during subsequent storage for 21 days at 7 degrees C and after 5 days of shelf life at 20 degrees C. The chilling tolerance induced by MJ was positively correlated with the reduction in the percent ion leakage of mango tissue. The overall quality of MJ-treated fruit was also better than that of control fruit. MJ treatment increased the total soluble solids but did not affect titratable acidity or pH. MJ also did not change the normal climacteric rise in respiration, water loss, and softening rates. The efficacy of MJ to reduce chilling injury and decay of mango could be related to the tolerance induced at low temperature. It was concluded that MJ treatment may prevent chilling injury symptoms of mango without altering the ripening process.     

Grape Seed-Derived Procyanidins Decrease Dipeptidyl-peptidase 4 Activity and Expression

Dipeptidyl-peptidase 4 (DPP4) inhibitors are among the newest treatments against type 2 diabetes. Since some flavonoids modulate DPP4 activity, we evaluated whether grape seed-derived procyanidins (GSPEs), which are antihyperglycemic, modulate DPP4 activity and/or expression. In vitro inhibition assays showed that GSPEs inhibit pure DPP4. Chronic GSPE treatments in intestinal human cells (Caco-2) showed a decrease of DPP4 activity and gene expression. GSPE was also assayed in vivo. Intestinal but not plasmatic DPP4 activity and gene expression were decreased by GSPE in healthy and diet-induced obese animals. Healthy rats also showed glycemia improvement after oral glucose consumption but not after an intraperitoneal glucose challenge. In genetically obese rats, only DPP4 gene expression was down-regulated. Thus, procyanidin inhibition of intestinal DPP4 activity, either directly and/or via gene expression down-regulation, could be responsible for some of their effects in glucose homeostasis.     

Late nitrogen fertilization affects nitrogen remobilization in wheat

A pot experiment with wheat plants was carried out to study how late application of nitrogen (N) fertilizer affects the use of pre‐anthesis N reserves during the grain‐filling period. Increasing doses of N fertilizer were applied (0, 40, and 52 mg N plant^–1), either in two amendments (growth stages GS20 and GS30, according to Zadoks scale) or in three amendments (GS20, GS30, and GS37). The experiment was arranged in a complete randomized three‐block design with 129 plants per treatment. The plants were watered daily, harvested every 2 d between anthesis and maturity, and were separated into roots, leaf sheaths, leaf blades, and ears for further N determination. Grain N concentration improved due to a late N application in GS37 by 14% (higher N dose) and by 7% (further splitting the same N‐fertilizer dose, respectively). The higher the N‐fertilizer dose applied, the greater was the amount of pre‐anthesis reserves in vegetative organs, these reserves became later available for remobilization. Although splitting the same N dose in three amendments did not increase the N reserves, these reserves were more efficiently remobilized allowing an improvement in grain N concentration. The fertilizer management did not change the temporary pattern of N accumulation in the ear, but did induce a change in the amount of N remobilized and in the contribution of each organ (root, leaf sheath, leaf blade) to this remobilization. Late N amendment allowed a greater N availability of leaf blades and ear N reserves (from 20% up to 26% and from 19% up to 22%, respectively) for remobilization towards the grain, decreasing the root contribution from 28% down to 15%, while the contribution of leaf sheaths was maintained around 35% irrespective of the N applied.     

Nitrosation of phenolic compounds: inhibition and enhancement

The nitrosation of phenol, m-, o-, and p-cresol, 2,3-, 3,5-, and 2, 6-dimethylphenol, 3,5-di-tert-butylphenol, 2,4,6-trimethylphenol, o-chlorophenol, and o-bromophenol was studied. Kinetic monitoring of the reactions was accomplished by spectrophotometric analysis of the products at 345 nm. At pH > 3, the dominant reaction was C-nitrosation through a mechanism that appears to consist of an attack on the nitrosatable substrate by NO(+)/NO(2)H(2)(+), followed by a slow proton transfer. The finding of an isokinetic relationship supports the idea that the same mechanism operates throughout the series. The observed sequence of nitrosatable substrate reactivities is explained by (i) the preferred para-orientation of the hydroxyl group for the electrophilic attack of nitrosating agents, (ii) steric hindrance of alkyl substituents, which reduces or prevents attack by nitrosating agents, and (iii) the hyperconjugative effect of the methyl substituent, which causes electronic charge to flow into the aromatic nucleus, as well as the opposite electronic withdrawing effect induced by halogen substituents. The results show that potential nitrosation of widespread environmental species such as chlorophenols is negligible, but more attention should be paid to polyphenols with strongly nucleophilic carbon atoms.     

The genetic diversity associated with seed proteins in a collection of Spanish underground vetches (<Emphasis Type="Italic">Vicia sativa</Emphasis> L. subsp. <Emphasis Type="Italic">amphicarpa</Emphasis> (Dorthes) Asch. et Graebn.)

The characterization of plant genetic resources is the first step towards improving their use. The Spanish Plant Genetic Resources Centre, which belongs to the National Institute for Agricultural and Food Technology Research (CRF-INIA), conserves accessions of wild underground vetches collected in Spain. In the present work, 26 underground vetch accessions were characterized in terms of their seed storage proteins (separated by SDS-PAGE) as a means of assessing the genetic variation of these plants and their agronomic value. Vicia sativa cv. Vereda was used as control. A total of 54 bands were detected, of which 49 were polymorphic. Fifty eight different electrophoretic patterns were observed in total. Protein bands were scored in terms of their presence (1) or absence (0) for all the seeds studied, and two matrices constructed, one with all the bands present in each accession, the other with the different patterns for each accession. Dendrograms based on the Jaccard similarity index and the UPGMA clustering method were produced from these matrices, and the degree of genetic variation between and within accessions was calculated. The groups obtained were compared with the chromosome number for each accession. The results reflect the great diversity of underground vetch seed storage proteins. The aerial and underground seeds of 16 accessions were then analysed separately. In some cases, the aerial and underground flowers of the same plant produced different proteins.     

Ultrasensitive detection of genetically modified maize DNA by capillary gel electrophoresis with laser-induced fluorescence using different fluorescent intercalating dyes

In this work, four different fluorescent intercalating dyes are compared for the ultrasensitive CGE-LIF detection of DNA from transgenic maize in flours. The fluorescent intercalating dyes compared are YOPRO-1, SYBR-Green-I, Ethidium bromide (EthBr), and EnhanCE. For all the four dyes optimum concentrations are established, and efficient separations of DNA fragments ranging in size from 80 to 1000 bp are obtained. The comparative study demonstrates that SYBR-Green-I and YOPRO-1 provide better limits of detection (LODs) than EnhanCE or EthBr (i.e., LODs are, respectively, 700, 1000, 11300, and 97400 zmol, calculated for a 200-bp DNA fragment). Separations using YOPRO-1 are faster than those using SYBR-Green-I (30 min vs 47 min for the analysis of the 80-1000 bp DNA fragments). Also, separations using YOPRO-1 are more efficient than those using SYBR-Green-I (e.g., 2.4 x 10(6) plates/m vs 1.6 x 10(6) plates/m, respectively, calculated for the 200-bp fragment). Also, buffer depletion and cost per analysis are worse with SYBR-Green-I than with YOPRO-1. Therefore, YOPRO-1 was selected as the preferred intercalating dye. Using this fluorescent compound, analysis time reproducibility for the CGE-LIF separation of the DNA fragments is determined to be better than 1.7% (% RSD, n = 10) within the same day, and better than 1.9% (% RSD, n = 30) for three different days. Moreover, the fluorescence signal obtained using this dye is shown to vary linearly with the DNA concentration in the range studied, i.e., 1-500 ng/microL. It is demonstrated that by using this method 0.01% of transgenic maize can be detected in flour by direct injection of the PCR-amplified sample.     

Volatile compounds in Hispánico cheese manufactured using a mesophilic starter,a thermophilic starter,and bacteriocin-producing Lactococcus lactis subsp. lactis INIA 415

The effect of the addition of Lactococcus lactis subsp. lactis INIA 415, a strain harboring the structural genes of nisin Z and lacticin 481, on the formation of volatile compounds in Hispánico cheese manufactured with a mesophilic starter or with the mesophilic starter and a thermophilic starter was investigated. Addition of bacteriocin-producing L. lactis subsp. lactis INIA 415 to milk enhanced the formation of 2-methyl-propanal, 2-methylbutanal, 3-methylbutanal, 2-methyl-1-propanol, 3-methyl-1-butanol, 1-octanol, 2-butanone, and 2,3-butanedione. On the other hand, addition of thermophilic starter enhanced the formation of acetaldehyde, ethanol, 3-methyl-2-buten-1-ol, ethyl butanoate, ethyl hexanoate, 2-butanone, and 2,3-butanedione in Hispánico cheese. Stepwise discriminant analysis using the relative abundances of volatile compounds classified cheeses by type of starter, with function 1 related to thermophilic starter and function 2 to bacteriocin producer.     

Kinetic and Thermodynamic Behavior on the Sorption of Clindamycin from an Aqueous Medium by Modified Surface Zeolitic Tuffs

Clindamycin (CLD), an antibiotic derivate of lincomycin, is widely used; the presence of this drug in the wastewater and the environment could produce resistance in bacteria. In this work, the sorption of this drug by two surfactant-modified zeolitic tuffs was studied considering contact time, initial concentration, pH, and temperature. The kinetic behavior indicates that the equilibrium times were between 15 and 12 h for all materials, and the results were best adjusted to Ho and Mc Kay model. The highest adsorption was obtained with the hexadecyltrimethylammonium-modified zeolitic tuff from Oaxaca, Mexico (1.56 mg/g). The sorption isotherms obtained showed a linear behavior, indicating a partition mechanism. The thermodynamic parameters were determined from the isotherms at different temperatures and Van Ho equation; the processes are exothermic and not spontaneous. The best pH for the adsorption is between 8 and 11. The results show that the modified zeolitic tuffs are potential materials for the adsorption of CLD from water.     

Phylogenetic position of the disjunct species <Emphasis Type="Italic">Musa ornata</Emphasis> (Musaceae): first approach to understand its distribution

Musa L. commonly known as the banana group is one of the most important and oldest food crops of humankind. Among the wild relatives with ornamental interest in the genus, Musa ornata Roxb. shows a disjunct distribution between Asia and North America (Mexico). The wild occurrence of this species in Mexico has led to speculation about the evolutionary relationships with its Asian relatives. This study examined the phylogenetic relationships between intercontinental specimens of this species and, based on registered evidence, explored the more likely hypothesis about the origins of its distribution. The phylogeny of intercontinental specimens, along with other representatives of the same genus, was carried out using three molecular markers (ITS, trnL-F, and atpB-rbcL) and applying three phylogenetic reconstruction methods: maximum parsimony, maximum likelihood, and Bayesian inference. The genetic analysis of the combined dataset grouped together all the Mexican and most Asian specimens, but the monophyly of the species was not supported. The relationships suggest that Mexican populations may have originated from an Asian invasion. However, several studies and historical documents suggest the presence of Musa in America long before the arrival of Europeans. Based on its current distribution, phylogenetic evidence, and fossil record, this species’ disjunct distribution could be explained in terms of an ancestral distribution range that encompassed America and Asia, followed by its subsequent restriction to the Old World and a secondary dispersal by humans. However, further studies are necessary to shed more light on the origins of this disjunct distribution.