Characterization of the acyl-ACP thioesterases from Koelreuteria paniculata reveals a new type of FatB thioesterase.

Koelreuteria paniculata is a deciduous tree, popular in temperate regions for its ornamental value, which accumulates unusual cyanolipids in its seeds. The seed oil of this plant is rich in the unusual cis-11-eicosenoic fatty acid (20:1, or gondoic acid), a monounsaturated oil of interest to the oleochemical industry. In higher plants, de novo fatty acid biosynthesis takes place in the plastids, a process that is terminated by hydrolysis of the thioester bond between the acyl moiety and the ACP by acyl-ACP thioesterases. The specificity of acyl-ACP thioesterases is fundamental in controlling the fatty acid composition of seed oil. To determine the mechanisms involved in fatty acid biosynthesis in K. paniculata seeds, we isolated, cloned and sequenced two cDNAs encoding acyl-ACP thioesterases in this plant, KpFatA and KpFatB. Both of them were expressed heterologously in Escherichia coli and characterized with different acyl-ACP substrates. The K. paniculata FatB2 displayed unusual substrate specificity, so that unlike most FatB2 type enzymes, it displayed preference for oleoyl-ACP instead of palmitoyl-ACP. This specificity was consistent with the changes in E. coli and N. benthamiana fatty acid composition following heterologous expression of this enzyme. KpFatB also showed certain genetic divergence relative to other FatB-type thioesterases and when modelled, its structure revealed differences at the active site. Together, these results suggest that this thioesterase could be a new class of FatB not described previously.

Removal of emerging organic contaminants in a poplar vegetation filter.

Vegetation filters (VFs), a type of land application system, are a robust technology based on natural treatment mechanisms for the removal of wastewater contaminants. Their capacity to attenuate emerging organic contaminants (EOCs) has not yet been evaluated. The present study reports the results of a 2-year EOC monitoring carried out using a poplar VF receiving wastewater primarily treated by an Imhoff tank. The compounds selected included analgesics, a ß-adrenergic blocker, stimulants, an anticonvulsant, an anti-depressant, an anti-inflammatory, an antibiotic and analgesic and stimulant metabolites. EOCs were analysed in the Imhoff tank effluent, in the infiltrated water at a depth of 90cm and in the groundwater at a depth of 10m. The results demonstrated that EOC attenuation was more significant in the first 90cm than in the rest of the soil profile. The removal efficiency for all of the selected EOCs was higher than 90% with the exception of ketoprofen, which may pose a higher threat of groundwater contamination. The observed attenuation correlated with the hydrophobicity and charge state of the EOCs. The higher persistence of the metabolites 4-AAA and 4-FAA shows that progression in the degradation pathway does not always imply a mitigation of contamination.

Phospholipase Dalpha from sunflower (Helianthus annuus): cloning and functional characterization.

D type phospholipases (PLD) are enzymes that hydrolyze the head group of phospholipids to produce phosphatidic acid. This activity is ubiquitous in plant tissues, and has been isolated and characterized from different species and organs. Several families of these proteins have been described in plants on the basis of their gene sequences (PLD alpha, beta, gamma, delta, zeta and epsilon). They have been shown to be involved in many metabolic events, such as response to abiotic stress, signal transduction, and membrane lipid turnover and degradation. In the present study, PLD activity was measured in the soluble fractions isolated from different organs of this plant. A PLD of alpha type was cloned from leaf cDNA that was responsible for most of this activity. The gene encoding this 810 aa protein was heterologously expressed in E. coli. This protein was not lethal for the eukaryotic host, although it altered its phospholipid profile. PLDalpha was purified to almost homogeneity by His-tag affinity chromatography, displaying an optimum pH of 6.5 and strong dependence on the presence of Ca(2+) and SDS in the assay medium. The enzyme was active towards phosphatidylcholine, Phosphatidylethanolamine and phosphatidylglycerol. Furthermore, the HaPLDalpha gene was found to be expressed at high levels in leaf and stem tissues.

Effect of the ferredoxin electron donor on sunflower (Helianthus annuus) desaturases.

Ferredoxins are proteins that participate in photosynthesis and in other processes that require reducing equivalents, such as the reduction of nitrogen or fatty acid desaturation. Two classes of ferredoxins have been described in plants: light-regulated photosynthetic ferredoxins and heterotrophic ferredoxins whose activity is not influenced by light. Genes encoding the two forms of ferredoxin have been cloned and characterized in developing sunflower cotyledons. Here, these genes were overexpressed in Escherichia coli and they were purified by ion exchange and size exclusion chromatography to study their capacity to supply electrons to two different sunflower desaturases: soluble stearoyl-ACP desaturase from sunflower cotyledons, and membrane bound desaturase FAD7 expressed in yeast. In both cases photosynthetic ferredoxin was the form that promoted the strongest desaturase activity.

Bypass gástrico convencional y laparoscópico en el tratamiento de la obsesidad mórbida. Evaluación comparativa de la calidad de vida por medio del Test de Baros / Laparoscopic or open gstric bypass for the treatment of morbid obesity. Comparative bariatric evaluation of the quality of life

La obesidad mórbida representa un problema mundial cuya prevalencia se encuentra en aumento, sólo el enfoque quirúrgico ha demostrado resultados persistentes en cuanto a la pérdida de peso de manera permanente. Objetivo: evaluación del impacto social de la pérdida de peso en el paciente obeso posterior al tratamiento quirúrgico por medio de un bypass laparoscópico o convencional y análisis de costos operativos.

Morbid obesity represents a health-related problem rising all over the world, just the surgical management has demonstrted persistent and constant outcome in weight lose. Objective: Evaluations of the social impact and operative cost in weight lose obese morbid patients after laparoscopic or open gastric bypass.

Bypass gástrico convencional y laparoscópico en el tratamiento de la obsesidad mórbida. Evaluación comparativa de la calidad de vida por medio del Test de Baros / Laparoscopic or open gstric bypass for the treatment of morbid obesity. Comparative bariatric evaluation of the quality of life

La obesidad mórbida representa un problema mundial cuya prevalencia se encuentra en aumento, sólo el enfoque quirúrgico ha demostrado resultados persistentes en cuanto a la pérdida de peso de manera permanente. Objetivo: evaluación del impacto social de la pérdida de peso en el paciente obeso posterior al tratamiento quirúrgico por medio de un bypass laparoscópico o convencional y análisis de costos operativos.(AU)

Morbid obesity represents a health-related problem rising all over the world, just the surgical management has demonstrted persistent and constant outcome in weight lose. Objective: Evaluations of the social impact and operative cost in weight lose obese morbid patients after laparoscopic or open gastric bypass.(AU)

Life cycle assessment of wastewater treatment options for small and decentralized communities.

Sustainability has strong implications on the practice of engineering. Life cycle assessment (LCA) is an appropriate methodology for assessing the sustainability of a wastewater treatment plant design. The present study used a LCA approach for comparing alternative wastewater treatment processes for small and decentralised rural communities. The assessment was focused on two energy-saving systems (constructed wetland and slow rate infiltration) and a conventional one (activated sludge process). The low environmental impact of the energy-saving wastewater treatment plants was demonstrated, the most relevant being the global warming indicator. Options for reduction of life cycle impacts were assessed including materials used in construction and operational lifetime of the systems. A 10% extension of operation lifetime of constructed wetland and slow rate infiltration systems led to a 1% decrease in CO2 emissions, in both systems. The decrease in the abiotic depletion was 5 and 7%, respectively. Also, replacing steel with HDPE in the activated sludge tank resulted in a 1% reduction in CO2 emission and 1% in the abiotic depletion indicator. In the case of the Imhoff tank a 1% reduction in CO2 emissions and 5% in the abiotic depletion indicator were observed when concrete was replaced by HDPE.

Lipoxygenase pathway in olive callus cultures (Olea europaea).

Stimulation of the lipoxygenase pathway in olive fruit initiates a cascade of reactions that begins with the regio- and stereospecific di-oxygenation of polyunsaturated fatty acids containing a cis, cis-1,4 pentadiene moiety. Later products of the pathway include volatiles that influence the organoleptic properties of harvested olive oil. In this study, we have investigated lipoxygenase activity in olive callus cultures, and found that there is evidence of several isoforms of the enzyme with different pH optima and substrate specificities. Endogenous lipoxygenase activity was detected throughout the growth cycle of olive callus, particularly during the log phase of growth, suggesting that olive lipoxygenases are intimately involved in growth. The most prominent lipoxygenase activity in tissue cultures was found to be soluble but significant activities were detected in the plastid fraction. In addition, hydroperoxide lyase (HPL) activity was measured in the calli; both 13- and 9-HPL activities were found which were particulate.

Alcohol dehydrogenases from olive (Olea europaea) fruit.

Alcohol dehydrogenase activity was detected in extracts from the pericarp tissues of developing olive fruits using hexanal as the substrate. Total activity in the crude extract was 20-fold higher with NADPH than with NADH. Three discrete enzymes were resolved by means of a purification protocol involving ammonium sulfate fractionation followed by ion-exchange and affinity chromatography. One of the enzymes was NAD-dependent and displayed a high K(m) for hexanal (K(m) = 2.1 mM). Two NADP-dependent alcohol dehydrogenases were resolved, one showing a high K(m) for hexanal (K(m) = 1.9 mM) and the second with a lower K(m) for the same substrate (K(m) = 0.04 mM). The three enzymes have been partially purified and their kinetic parameters and specificities for various aldehydes determined. The involvement of these enzymes in the biogenesis of six carbon alcohols constituent of the aroma of olive oil is discussed.

Compressive myelopathy due to dialysis-associated amyloidosis.

A 66-year-old woman presented a spastic quadriparesis due to compression of the cervical cord 6 years after the beginning of chronic hemodialysis. Five years later, she developed a second episode of compressive myelopathy affecting the lumbar spine. On both occasions, surgical laminectomy with removal of fibroligamentous rings that compressed the cord led to a total recovery of the patient. Histological study demonstrated the presence of massive amyloid deposits in the surgically excised material.