Microscale direct transesterification of microbial biomass with ethanol for screening of microorganisms by its fatty acid content

Abstract We present an improved method of direct transesterification suitable for the quantitative analysis of multiple dry samples for its fatty acid content, using a minimal amount of biomass and reactants. The method features an acid-catalyzed direct alcoholysis of microgram samples of dry biomass; the rationale behind the solvent and reagent proportions chosen is discussed. The method was validated using seven microbial strains with diverse lipid content (Saccharomyces cerevisiae, Saccharomyces boulardii, Candida tropicalis, Haematococcus pluvialis, Chlorella vulgaris, Spirulina platensis and Schizochytrium limacinum), and compared with a macroscale direct transesterification method, and with gravimetric analysis of lipids extracted with solvents. The microscale method showed a conversion of 98.06 ± 0.87% of the lipids, using approximately 3 mg of dry biomass, 1mL of 0.2M H2SO4 dissolved in anhydrous ethanol (the acid is the catalyzer and ethanol the reactant)). The mixture was maintained at 70 °C for 20 h with periodic mixing, and then extracted with 2mL n-heptane and analyzed by GC-FID. The lipid content was then calculated considering dilution and sample mass. This method is effective, reliable, and technically attractive for analytical and comparative purposes.

Desinfectantes en aerosol como alternativa de control ambiental de los hongos anemófilos en viviendas / Disinfectant spray as an alternative environmental control of airborne fungi in houses

El objetivo de este trabajo fue evaluar el efecto de productos desinfectantes comerciales en aerosol sobre la carga de hongos ambientales en habitaciones de viviendas, teniendo en cuenta que las personas, principalmente los niños, pasan la mayor parte del día en las mismas. Además, se estudió, a través de encuestas, las preferencias del público a la hora de adquirir los desinfectantes comerciales ensayados. El número de UFC/placa fue variable dentro de la misma habitación para las distintas mediciones realizadas antes de la aplicación de los productos desinfectantes. Los porcentajes de inhibición del crecimiento fúngico fueron variables dependiendo del producto desinfectante ensayado y de la habitación muestreada. Dichos porcentajes no fueron diferentes significativamente entre los desinfectantes. Los valores de temperatura estuvieron dentro de un rango de 11 a 19,5 ºC y el porcentaje de humedad relativa varió entre un 64 a 85 por ciento. El 89 por ciento de los encuestados conocía la existencia de desinfectantes ambientales en aerosol. El 78 por ciento conocía el Lysoform®, seguido por Glade® antitabaco y Ayudin®. Dentro de los productos más utilizados, el 54 por ciento de los encuestados indicó el producto Lysoform®. La mayoría de los consumidores eligieron a los desinfectantes por lo que conocen y los medios de comunicación influyeron en el 29 por ciento de los consumidores al momento de elegir el desinfectante. Estos productos ensayados son recomendables en una habitación para disminuir la carga de hongos ambientales y así reducir el efecto perjudicial de estos hongos sobre las personas que la utilizan.

The aim of this study was to evaluate the effect of commercial disinfectant spray on the concentration of airborne fungi in bedrooms, considering that people, especially children, spend most of the day in them. Also, public preferences through surveys were studied when acquiring commercial disinfectants tested. The number of CFU/Petri dish was variable within the same bedroom for the different measurements performed before application of the disinfectant. Percent inhibition of fungal growth were variable, depending on the disinfecting product tested and sampled bedroom. These percentages were not significantly different between the disinfectants. The temperature values were within a range of 11 to 19.5° C and relative humidity percentage ranged from 64 to 85 percent. Eighty nine percent of respondents knew about environmental disinfectant spray. Seventy-eight percent knew about Lysoform®, followed by antismoking Glade® and Ayudin®. Among the most widely used products, 54 percent of respondents said the Lysoform® product was the most used. Most consumers chose known disinfectants and, when choosing a disinfectant, the media influenced 29 percent of consumers. The used products are recommended to be used in a bedroom to decrease the number of airborne fungi and thus reduce the harmful effect of these fungi on the people that use this room.

Validación in-house y determinación de grasa por gravimetría en conservas de raciones de combate del Ejército de Tierra / Validation in-house and uncertainty estimation by recovery assays in fat gravimetric determination in canned foods of combat rations Spanish Army

OBJETIVOS: Validación in-house y estimación de la incertidumbre mediante ensayos de recuperación en la determinación de grasa en conservas de raciones de combate, utilizando la información generada en el proceso de validación. MATERIAL Y MÉTODOS: La determinación de la grasa se realiza por gravimetría, previa hidrólisis con ácido clorhídrico y extracción de la grasa con éter de petróleo 40-60 º, mediante el sistema Soxtec System Tecator. Se analizan matrices y concentraciones (baja, media y alta) representativas de las muestras de rutina utilizando un diseño anidado de tres factores. La veracidad del método se evalúa estimando el sesgo proporcional a partir de los ensayos de recuperación. La estimación de la incertidumbre se realiza aplicando la ley de propagación de la incertidumbre, agrupando términos relativos de incertidumbre de precisión, recuperación y pureza del estándar. La incertidumbre expandida se obtiene aplicando un factor de cobertura K=2 (nivel de confianza del 95%). RESULTADOS: Se obtienen recuperaciones medias de grasa entre 0,95 y el 1,01 en tres niveles de concentración, por lo que la exactitud del método se considera buena. Los porcentajes de incertidumbre expandida relativa que se declaran para cada nivel de concentración de grasa son los siguientes: 0,50% (17,64%); 0,5-1,00% (13,09%); 1,00-16,55% (6,62%); 16,55-35,14% (6,00%); 35,14-50% (7,00%). CONCLUSIONES: La incertidumbre se estima utilizando la información generada durante el proceso de estimación del sesgo proporcional y puede aplicarse al análisis de futuras muestras de rutina con este método analítico

OBJECTIVES: Validation in-house and estimation of the uncertainty through recovery assays in determination of fat in canned foods of combat rations by gravimetríc using the information generated in the validation process. MATERIAL AND METHODS: Fat determination is carried out by gravimetríc, previously hydrolyzed with hydrochloric acid and extraction of fat with ether of petroleum 40-60 º, by means of Soxtec System Tecator. Representative matrix and concentrations of the future routine samples are analyzed (low, medium, high) by using a nested design of three factors. The trueness of the method is evaluated by estimating the proportional bias starting from the recovery assays. The uncertainty estimate is carried out by applying the propagation law of errors, that contains terms of uncertainty of precision, recovery and standard purity. The expanded uncertainty is obtained applying a coverage factor K=2 (confidence level of 95%). RESULTS: The accuracy of the method can be considered good. Fat recoveries are obtained between 0,95 and 1,01 for the three concentration levels. The percentages of relative expanded uncertainty that are declared for each concentration level of fat in the samples of routines are the following ones: 0,50% (17,64%); 0,50-1,00% (13,09%); 1,00-16,55% (6,62%); 16,55-35,14% (6,00%); 35,14-50% (7,00%). CONCLUSIONS: The estimated uncertainty is carried out by using the information generated during the proportional bias estimate process, and it can be applied to the future routine samples analysis by this analytic method

Uso de la metodología Seis Sigma en la preparación de mezclas de nutrición parenteral / Use of the Six Sigma methodology for the preparation of parenteral nutrition mixtures

Objetivo: Usar las herramientas de la metodología Seis Sigma para el control estadístico de elaboración de mezclas de nutrición parenteral en el punto crítico de control gravimétrico. Métodos: Entre agosto de 2010 y septiembre de 2013 se realizó análisis gravimétrico al 100% de las mezclas dividiendo los datos en dos grupos adultos y neonatos. Se determina el porcentaje de aceptación, las gráficas de tendencia y el nivel de sigma. Se realizo análisis de normalidad con el test Shapiro Wilk y se calcula el porcentaje total de mezclas dentro de límites de especificación. Resultados: Los datos de gravimetría entre agosto de 2010 y septiembre de 2013 cumplen con el test de normalidad (W = 0,94) y presentan mejoramiento en el nivel de sigma a través del tiempo llegando a 6/6 en adultos y 3.8/6 para neonatos. Se logra que el 100% de las mezclas para adultos y neonatos cumplan con límites de especificación, estando siempre dentro de los límites de control del proceso. Conclusión: Los planes de mejoramiento junto a las herramientas de la metodología Seis Sigma permiten controlar el proceso, garantizando la concordancia entre la orden médica y el contenido de la mezcla

Objective: To use the tools of the Six Sigma methodology for the statistical control in the elaboration of parenteral nutrition mixtures at the critical checkpoint of specific density. Methods: Between August of 2010 and September of 2013, specific density analysis was performed to 100% of the samples, and the data were divided in two groups, adults and neonates. The percentage of acceptance, the trend graphs, and the sigma level were determined. A normality analysis was carried out by using the Shapiro Wilk test and the total percentage of mixtures within the specification limits was calculated. Results: The specific density data between August of 2010 and September of 2013 comply with the normality test (W = 0.94) and show improvement in sigma level through time, reaching 6/6 in adults and 3.8/6 in neonates. 100% of the mixtures comply with the specification limits for adults and neonates, always within the control limits during the process. Conclusion: The improvement plans together with the Six Sigma methodology allow controlling the process, and warrant the agreement between the medical prescription and the content of the mixture

Control gravimétrico en la nutrición parenteral: de la teoría a la práctica / Weight monitoring in parenteral nutrition: from theory to practice

Objetivo: Valorar la utilidad de un control gravimétrico rutinario como control de calidad tras la elaboración de nutriciones parenterales (NP) con un error gravimétrico inferior al ± 5%. Material y métodos: Estudio prospectivo, en el que durante 2 meses se pesaron diariamente de 5 a 8 NP de gran volumen y durante 4 meses todas las NP de pequeño volumen, considerándose este valor el peso real. El peso teórico se calculó teniendo en cuenta las densidades, los volúmenes de todos los productos utilizados en la elaboración y el peso de las bolsas multicapas utilizadas. El error gravimétrico se calculó en porcentaje con respecto al peso teórico. Resultados: Se pesaron 168 NP de gran volumen y 42 de pequeño volumen, las medias de los errores gravimétricos fueron 1,42% (SD = 1,31) y 1,26% (SD = 0,64), con un error gravimétrico inferior al 5% en el 98,8% y 100% respectivamente. Conclusión: Establecer un control gravimétrico rutinario es una estrategia útil que puede ayudar a garantizar la calidad de la elaboración de NP (AU)

Objective: To assess the usefulness of establishing a routine gravimetric as quality assurance after the development of parenteral nutrition (PN) with a gravimetric error less than ± 5%. Material and methods: Prospective study in which 5 to 8 large volume PN were weighed daily during 2 months and for 4 months all small volume PN, considering this the real weight. The theoretical weight was calculated taking into account the densities, volumes of all products used in processing and the weight of the bags used. The gravimetric error was calculated as a percentage compared to the theoretical weight. Results: 168 large volume PN and 42 small volume were weighed, gravimetric errors measures were 1,42% (SD = 1,31) and 1,26% (SD = 0,64), with a gravimetric error less than 5% in 98,8% and 100% respectively. Conclusion: Establishing a routine gravimetric control is an useful strategy that can help to guarantee the quality of the PN development (AU)

Métodos de secagem e rendimento dos extratos de folhas de Plectranthus barbatus (boldo-da-terra) e P. ornatus (boldo-miúdo) / Methods estimated drying and percentage of extracts in leaves of Plectranthus barbatus (Brazilian bold) and P. ornatus (false bold)

Plectranthus sp. pertence à família Lamiaceae e inclui cerca de 300 espécies. Duas delas, P. barbatus (PB) e P. ornatus (PO) destacam-se pelo interesse medicinal. As principais substâncias encontradas em Plectranthus sp. são os diterpenóides, óleos essenciais e compostos fenólicos. A melhor forma de utilizar as folhas de PB e PO é a fresco; porém, na comercialização há necessidade de recorrer a processos de secagem. Entretanto, isto pode interferir no princípio ativo, desta forma, estudos para determinar o melhor método gravimétrico são importantes. O objetivo deste estudo foi avaliar qual o melhor método de secagem, onde haja maior perda de água possível, e calcular os rendimentos dos extratos visando avaliar se o método gravimétrico interfere na quantidade de extrato produzido. Desta forma, utilizou-se quatro métodos de secagem e após evaporação do solvente, fez-se o cálculo do rendimento dos extratos secos. O percentual de água foi superior em PB e PO (média geral de 90,12±8,22 por cento). Dentre as secagens, em estufa de ventilação forçada (EVF) foi mais eficiente em PB (88,87 por cento) e em estufa convencional (ECO) foi melhor em PO (95,13 por cento). O maior rendimento do extrato seco em PB foi na secagem em camada delgada (CD) (20,96 por cento), enquanto que em PO foi ECO (41,34 por cento). Não houve correlação entre o método de secagem e o rendimento de extrato obtido.

Plectranthus sp. belongs to the family Lamiaceae and includes about 300 species. Two of them, P. barbatus (PB) and P. ornatus (PO), have medicinal interest. The main substances found in Plectranthus sp. are the diterpenoids, essential oils and phenolic compounds. The best way to use the leaves of PB and PO is cool; but for marketing there is a need of resort to drying processes. However, this may interfere on the values of active principle; thus, studies to determine the best gravimetric methods are important. The objective of this study was to evaluate the best method of drying, where there the greater loss of water possible, and calculate the percentage of the extracts to assess whether the gravimetric method interferes with the amount of extract produced. To this was done by drying four different methods ventilated dry (EVF), conventional drying (ECO), microwave (MCO) and layer thing (CD) and after evaporation of the solvent, was made the calculation the percentage of the dried extract. The water content was higher in PB and PO (overall average of 90.12±8.22 percent). Among the drying, EVF was more efficient for PB (88.87 percent) and ECO was better for PO (95.13 percent). The highest content of dry extract was for PB in to CD (20.96 percent), whereas for PO was in to ECO (41.34 percent). There is no relationship between the drying method and in the quantity of extract obtained.

Atividade antioxidante dos principais chás consumidos na cidade de Natal-RN / Antioxidant activity of the most consumed teas in the city of Natal-RN

This work investigated the most consumed teas in Natal city and evaluated their antioxidant effect. A research of the most consumed teas in Natal was carried out with subsequent analysis of in vitro antioxidant activity of such teas in oxidative aqueous system using beta-carotene/ linoleic acid. The most consumed teas were: boldo (Pneumus boldus), chamomile (Matriacaria recutica), lemongrass (Cymbopogon citratus) and anise (Pimpinella anisum). The best protection against the oxidation was given by a concentration of 200mg/Kg for teas made from boldo, lemongrass, anise, chamomile and a blend of herbs (mustard, cinnamon and anise), whilst teas made from boldo, chamomile and the blend of herbs showed an important antioxidant activity, without statistical differences between them. However, these teas showed superior antioxidant activity than anise and lemongrass teas. The results suggest an antioxidant effect of teas consumed in Natal city. However, further investigation and biological assays are necessary to make sure about the effect of those drinks in the organism as functional foods.

Este trabajo investigó la actividad antioxidante de los principales tés consumidos en la ciudad de Natal. Fue realizado un levantamiento de datos sobre los tés más consumidos en la ciudad de Natal y analizada la actividad antioxidante in Vitro, en sistema acuoso oxidativo utilizando beta-caroteno/ácido linoleico. Los tés más consumidos fueron: boldo (Pneumus boldus), manzanilla (Matriacaria recutita), caña santa o caña de limón (Cymbopogon citratus) y té de anís o hierba dulce (Pimpinella anisum). La concentración de 200mg/Kg fue la que presentó la mejor protección contra la oxidación, para los tés de boldo, caña santa, hierba dulce, mezcla de hierbas (mostaza, canela y anís) y manzanilla, presentando el té de boldo, manzanilla y mezcla de hierbas, papel antioxidante relevante sin diferencia estadística entre sí, pero superior a los tés de anís y caña santa. Los datos sugieren un efecto antioxidante de los tés consumidos en la ciudad de Natal/RN. Sin embargo, son necesarias otras investigaciones con el objetivo de comprobar el efecto como alimento funcional de estas bebidas en el organismo.

Este trabalho investigou os principais chás consumidos na cidade de Natal e avaliou o efeito antioxidante dos mesmos. Foi realizado um levantamento dos chás mais consumidos na cidade de Natal com posterior análise da atividade antioxidante in vitro desses chás em sistema aquoso oxidativo, utilizando beta-caroteno/ ácido linoléico. Os chás mais consumidos foram: boldo (Pneumus boldus), camomila (Matriacaria recutica), erva-cidreira (Cymbopogon citratus) e erva-doce (Pimpinella anisum). A concentração de 200mg/Kg foi a que mais apresentou a melhor proteção contra oxidação, para os chás de boldo, erva-cidreira, erva-doce, mistura de ervas (mostarda, canela e erva-doce) e camomila, enquanto os chás de boldo, camomila e mistura de ervas apresentaram relevante papel antioxidante sem diferença estatística entre si, porém, superior aos chás de erva-doce e cidreira. Estes dados sugerem, portanto um efeito antioxidante de chás consumidos na cidade de Natal/RN. Contudo, maiores investigações e ensaios biológicos são necessários a fi m de assegurar que haja efeito destas bebidas no organismo como alimento funcional.

Importância de compostos organossulfurados em sementes de leguminosas e em outros vegetais / Importance of organosulfur compounds in seeds of legumes and in other vegetables

Os compostos organossulfurados, representados pelos peptídeos ´GAMA`-glutamilsulfurados, são encontrados em grande quantidade em vegetais das famílias Alliaceae, Cruciferae e Leguminosae. A seus produtos de metabolização se atribui propriedades organolépticas típicas e quando são ingeridos por mamíferos, causam efeitos biológicos diversos. Estes efeitos são diferentes nestas três famílias, devido à formação de metabólitos secundários que dependem da presença ou ausência de enzimas específicas nestes vegetais. Na família Alliaceae, representada pelo alho e pela cebola, são produzidos compostos sulfurados, que além de serem precursores de aroma e de flavor característicos após a ruptura do tecido vegetal e a ação enzimática, se tornaram conhecidos pelos efeitos benéficos para a saúde humana. A via metabólica percorrida pelos compostos organossulfurados na família Cruciferae, dá origem, além do flavor, a compostos secundários diversos, incluindo o metanotiol e dissulfetos, altamente tóxicos para ruminantes, causando anemia hemolítica. Na família Leguminosae, os dipeptídeos sulfurados são encontrados principalmente nas sementes, sendo que o feijão Phaseolus vulgaris, L., dentre os gêneros estudados, os possui em maior concentração. A ´BETA’-glutamil-S-metil-L-cisteina e a S-metil-L-cisteina livre, podem em conjunto, representar ate ´50 POR CENTO1’ do conteúdo total de metionina presente no feijão, desaparecendo somente por ocasião da sua germinação...