RESUMO
Introdução: as indústrias de processamento de frutas geram grande quantidade de biomassa residual que poderia ser reaproveitada. Considerando o elevado volume de resíduos produzidos pelo descarte das sementes do abacate e destacando o alto teor de compostos bioativos, é um produto interessante para ser avaliado. Objetivo: avaliar a composição centesimal da farinha das sementes de abacate e as propriedades antioxidantes e antimicrobianos dos seus extratos. Métodos: os extratos foram obtidos por maceração da farinha do caroço do abacate desidratada em diferentes temperaturas (4,25 e 60 °C) utilizando n-hexano e etanol como solventes. Resultados: verificou-se que a farinha é uma excelente fonte de carboidratos, com alto teor de fibras, proteínas e minerais (N, K, Mg e Ca, entre outros). A temperatura da extração influenciou tanto no rendimento como no conteúdo de fenóis totais, atividades antioxidantes e antimicrobianas dos extratos. Os extratos etanoicos obtidos à 60 °C apresentaram maior rendimento (18%) e teor de compostos fenólicos totais (~840 mgEAG/g). Também os extratos etanoicos apresentaram maior atividade antioxidante (IC50= 0,013 mg/mL e 0,018 mg/mL) em temperaturas mais baixas de extração, 4 °C e 25 °C, respectivamente. Já extrato hexanóico obtido à 4 °C apresentou maior atividade antimicrobiana para as quatro bactérias testadas (L. monocytogenes, S. aureus, S. choleraesuis e E. coli). Conclusão: a farinha obtida das sementes de abacate, apresentam alto valor biológico e podem ser usadas como suplementos na alimentação humana.
SUMMARY Introduction: The fruit processing industries generate a large amount of residual biomass that could be reused. Considering the high volume of residues produced by the disposal of avocado seeds and highlighting the high content of bioactive compounds. Aim: To evaluate the centesimal composition of avocado seed flour and the antioxidant and antimicrobial properties of its extracts. Methodology: The extracts were obtained by macerating the avocado seed flour dehydrated at different temperatures (4,25 and 60 °C) using n-hexane and ethanol as solvents. Results: The flour is an excellent source of carbohydrates, with a high content of fibers, proteins and minerals (N, K, Mg and Ca, among others). The extraction temperature has influence in the yield and the content of total phenols, antioxidant and antimicrobial activities of the extracts. The ethanolic extracts obtained at 60 °C showed high yield (18%) and content of total phenolic compounds (~840 mg GAE/g). In addition, ethanol extracts showed high antioxidant activity (IC50= 0.013 mg/mL and 0.018 mg/mL) at lower extraction temperatures, 4 °C and 25 °C, respectively. Hexanoic extract obtained at 4 °C, on the other hand, showed greater antimicrobial activity for the four tested bacteria (L. monocytogenes, S. aureus, S. choleraesuis and E. coli). Conclusion: The flour obtained from avocado seeds has a high biological value and can be used as supplements in human food.
Introducción: las industrias de procesamiento de frutas generan una gran cantidad de biomasa residual que podría reutilizarse. Considerando el alto volumen de residuos que produce la disposición de semillas de aguacate y destacando el alto contenido de compuestos bioactivos. Objetivo: evaluar la composición centesimal de la harina de semilla de aguacate y las propiedades antioxidantes y antimicrobianas de sus extractos. Metodología: los extractos se obtuvieron macerando la harina de semilla de aguacate deshidratada a diferentes temperaturas (4, 25 y 60 °C) utilizando n-hexano y etanol como solventes. Resultados: la harina es una excelente fuente de carbohidratos, con un alto contenido en fibras, proteínas y minerales (N, K, Mg y Ca, entre otros). La temperatura de extracción influye en el rendimiento y el contenido de fenoles totales, actividades antioxidantes y antimicrobianas de los extractos. Los extractos etanólicos obtenidos a 60 °C mostraron alto rendimiento (18%) y contenido de compuestos fenólicos totales (~ 840 mg GAE/g). Además, los extractos de etanol mostraron una alta actividad antioxidante (IC50 = 0,013 mg/mL y 0,018 mg/mL) a temperaturas de extracción más bajas, 4 °C y 25 °C, respectivamente. El extracto hexano obtenido a 4 °C, en cambio, mostró mayor actividad antimicrobiana para las cuatro bacterias ensayadas (L. monocytogenes, S. aureus, S. choleraesuis y E. coli). Conclusión: la harina obtenida a partir de semillas de aguacate tiene un alto valor biológico y puede ser utilizada como complemento en la alimentación humana.
RESUMO
This review compiles and discusses the use of genetic markers applied in the study of the fish genus Hypostomus Lacépède, 1803 (Siluriformes: Loricariidae). The database comprises 51 peer-review articles that were published in the last 52 years (1968-2020) and that approach analysis based on different classes of genetic markers. The use of cytogenetic and enzymatic markers was predominantly especially in population studies with the genus Hypostomus, while mitochondrial markers were the majority in phylogenetic studies. Although significant methodological advances have occurred for molecular evaluation, they are still modestly applied to the study of neotropical fish genera, in which Hypostomus is included. New perspectives, especially on integrative approaches, are needed to improve our knowledge of the genetic functionality of fishes.
Assuntos
Peixes-Gato/genética , Animais , Código de Barras de DNA Taxonômico , Proteínas de Peixes/genética , Cariótipo , Repetições de Microssatélites , FilogeniaRESUMO
The subtropical riverine forests present a variation in soil water availability throughout the year, following precipitation seasonality. The objective of this work was to evaluate the responses of Cordia americana to different light intensities combined with soil flooding. Seedlings were acclimated to light treatments, with full sun and shade conditions. Sun and shade plants were subjected to soil flooding during periods of 10 (short) and 30 (longer) days. After 10 days, flooded plants had a higher root dry mass accumulation and soluble sugars content, regardless of the light condition. Shade plants presented higher shoot soluble sugars content in relation to the sun plants. After 30 days, a higher shoot soluble sugar content was observed in sun and shade flooded plants. In addition, a higher root soluble sugar content was also observed in sun plants under flood. Periods of short flooding, characterized in subtropical forests as from 5 to 15 days, favor the growth of shade plants and the roots sugar accumulation, fact that can explain the species distribution. However, long periods of flooding may be associated with light environment plasticity, suggesting that the sun plants present a higher flooding tolerance, directly associated with the ability to maintain the sugar content.
Assuntos
Aclimatação/fisiologia , Cordia/fisiologia , Inundações , Luz , Açúcares/metabolismo , Estações do Ano , Solo , Fatores de TempoRESUMO
This study aims at investigating pectin lyase bioproduction in submerged fermentation with synthetic medium and agro-industrial residues, using the filamentous fungus Aspergillus brasiliensis. The maximum pectin lyase activity in a synthetic medium (42 g/l pectin, 40 g/l yeast extract, and 0.02 g/l iron sulfate) was 31 U/ml, and 46 U/ml in the agro-industrial medium (160 g/l orange peel, 150 g/l corn steep liquor, and 300 g/l parboiled rice water), obtained over 60 and 124 h of bioproduction, 180 r/min, 30 â, pHinitial 5.5, and 5·106 spores/ml, respectively. Partial characterization of pectin lyase crude enzyme extract obtained from the synthetic medium and the one made of agro-industrial residues showed optimum conditions at pH of 5.5 and 4.5 and temperatures of 37 and 55 â, respectively. The Ed obtained was 3.13 and 9.15 kJ/mol, and the half-life time (t1/2) was 5.71 and 80 h at 55 â for pectin lyase produced in synthetic and agro-industrial medium, respectively.
Assuntos
Aspergillus/enzimologia , Biotecnologia/métodos , Proteínas Fúngicas/biossíntese , Resíduos Industriais/análise , Polissacarídeo-Liases/biossíntese , Agricultura/economia , Aspergillus/crescimento & desenvolvimento , Aspergillus/metabolismo , Biotecnologia/tendências , Brasil , Citrus sinensis/química , Produtos Agrícolas/química , Produtos Agrícolas/economia , Estabilidade Enzimática , Fermentação , Manipulação de Alimentos , Indústria de Processamento de Alimentos/economia , Frutas/química , Frutas/economia , Proteínas Fúngicas/química , Proteínas Fúngicas/economia , Proteínas Fúngicas/genética , Temperatura Alta , Concentração de Íons de Hidrogênio , Resíduos Industriais/economia , Cinética , Oryza/química , Polissacarídeo-Liases/química , Polissacarídeo-Liases/economia , Polissacarídeo-Liases/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/economia , Proteínas Recombinantes/isolamento & purificação , Zea mays/químicaRESUMO
The present work introduces new functional bionanocomposite materials based on layered montmorillonite and fibrous sepiolite clays and two biopolymers (carboxymethylcellulose polysaccharide and zein protein) to produce drug-loaded bionanocomposite films for antibiotic topical delivery. Neomycin, an antibiotic indicated for wound infections, was employed as the model drug in this study. The physical properties and the antimicrobial activity of these materials were evaluated as a function of the type of hybrid and the amount of zein protein incorporated in the bionanocomposite films. In addition, the interfacial and physicochemical properties of these new clay-drug hybrids have been studied through a combination of experimental and computational methodologies, where the computational studies confirm the intercalation of neomycin into the montmorillonite layers and the possible penetration of the drug in the tunnels of sepiolite, as pointed out by N2 adsorption and X-ray diffraction techniques. The antimicrobial activity of these bionanocomposite materials show that the films based on montmorillonite-neomycin display a more pronounced inhibitory effect of the bacterial growth than those prepared with the sepiolite-neomycin hybrid. Such effect can be related to the difficult release of neomycin adsorbed on sepiolite due to a strong interaction between both components.
RESUMO
Streams in urban areas are strongly impacted by the input of organic matter and metals, for instance copper (Cu) and zinc (Zn). These metals are essential for the aquatic biota, but when absorbed in excess they are toxic. In Chiro nomidae larvae, the deleterious effects of heavy metals can be ascertained by analyzing the morphological deformities of the larval mentum, a structure of the oral cavity. In this study, we evaluated I) the bioavailability of Cu and Zn in urban stream sediments and II) the relationship between Cu and Zn concentrations and the incidence of deformities in the mentum of Chironomus larvae. Chironomid flies were collected from four locations in two streams at an urban area in southern Brazil. They were identified and the incidence of deformities in the mentum was quantified. Sediment samples were collected at the same locations where larvae were collected, to quantify the bioavailable fractions of Cu and Zn. The concentrations of Cu in the sediment were similar between the collection sites. However, Zn concentrations varied among sites, being greater in the stretch directly influenced by the input of the organic waste. In total, 2,895 Chironomid larvae were collected. The incidence of deformities in the mentum was above 30% and was correlated with the concentrations of Cu (r = 0.68) and Zn (r = 0.87). This correlation indicates that the municipal waste that is thrown into the citys streams has influenced the occurrence of deformities.
Assuntos
Animais , Chironomidae/anatomia & histologia , Cobre/intoxicação , Monitoramento Ambiental , Zinco/intoxicação , Qualidade Ambiental , Área UrbanaRESUMO
Streams in urban areas are strongly impacted by the input of organic matter and metals, for instance copper (Cu) and zinc (Zn). These metals are essential for the aquatic biota, but when absorbed in excess they are toxic. In Chiro nomidae larvae, the deleterious effects of heavy metals can be ascertained by analyzing the morphological deformities of the larval mentum, a structure of the oral cavity. In this study, we evaluated I) the bioavailability of Cu and Zn in urban stream sediments and II) the relationship between Cu and Zn concentrations and the incidence of deformities in the mentum of Chironomus larvae. Chironomid flies were collected from four locations in two streams at an urban area in southern Brazil. They were identified and the incidence of deformities in the mentum was quantified. Sediment samples were collected at the same locations where larvae were collected, to quantify the bioavailable fractions of Cu and Zn. The concentrations of Cu in the sediment were similar between the collection sites. However, Zn concentrations varied among sites, being greater in the stretch directly influenced by the input of the organic waste. In total, 2,895 Chironomid larvae were collected. The incidence of deformities in the mentum was above 30% and was correlated with the concentrations of Cu (r = 0.68) and Zn (r = 0.87). This correlation indicates that the municipal waste that is thrown into the citys streams has influenced the occurrence of deformities.(AU)
Assuntos
Animais , Chironomidae/anatomia & histologia , Cobre/intoxicação , Zinco/intoxicação , Monitoramento Ambiental , Qualidade Ambiental , Área UrbanaRESUMO
This work reports the maximization of eugenyl acetate production by esterification of essential oil of clove in a solvent-free system using Novozym 435 as catalyst. The antimicrobial and antioxidant activities of clove essential oil and eugenyl acetate produced were determined. The conditions that maximized eugenyl acetate production were 60 °C, essential oil of clove to acetic anhydride ratio of 1:5, 150 rpm, and 10 wt% of enzyme, with a conversion of 99.87 %. A kinetic study was performed to assess the influence of substrates' molar ratio, enzyme concentration, and temperature on product yield. Results show that an excess of anhydride, enzyme concentration of 5.5 wt%, 50 °C, and essential oil of clove to acetic anhydride ratio of 1:5 afforded nearly a complete conversion after 2 h of reaction. Comparing the antibacterial activity of the essential oil of clove before and after esterification, we observed a decrease in the antimicrobial activity of eugenyl acetate, particularly with regard to minimum inhibitory concentration (MIC). Both eugenyl acetate and clove essential oil were most effective to the gram-negative than gram-positive bacteria group. The results showed a high antioxidant potential for essential oil before and particularly after the esterification reaction thus becoming an option for the formulation of new antioxidant products.
Assuntos
Anti-Infecciosos/química , Antioxidantes/química , Óleo de Cravo/química , Lipase/química , Óleos Voláteis/química , Syzygium/química , Enzimas Imobilizadas , Eugenol/química , Proteínas Fúngicas , CinéticaRESUMO
The objective of this work was to evaluate the kinetic of inactivation of Listeria monocytogenes using peracetic acid, chlorhexidine, and organic acids as active agent, determining the respective D-, Z-, and F-values. From our knowledge, these important results from an industrial view point are not available in the current literature, mainly for organic acids, pointing out the main contribution of the present work. Lower D-values were obtained for peracetic acid and chlorhexidine, compared with the organic acids. For the reduction of 6 log10 of L. monocytogenes using peracetic acid, at 0.2, 0.1, and 0.05% are necessary 7.08, 31.08, and 130.44 min of contact, respectively. The mathematical models of F-values showed that at concentrations lower than 0.15% one can verify an exponential increase in F-values, for both de chlorhexidine and peracetic acid. The organic acids presented a linear behavior, showing slight variation in F-values, is even more effective in under dosage. The results obtained are of fundamental importance in terms of industrial strategy for sanitization procedure, permitting to choose the best relation product concentration/exposure time, aiming at reducing costs without compromising the disinfectant efficiency.
RESUMO
Enzymatic esterification of citronella essential oil towards the production of geranyl and citronellyl esters may present great scientific and technological interest due to the well-known drawbacks of the chemical-catalyzed route. In this context, this work reports the maximization of geranyl and citronellyl esters production by esterification of oleic and propionic acids in a solvent-free system using a commercial immobilized lipase as catalyst. Results of the reactions showed that the strategy adopted for the experimental design proved to be useful in evaluating the effects of the studied variables on the reaction conversion using Novozym 435 as catalyst. The operating conditions that maximized the production of each ester were determined, leading, in a general way, to conversions of about 90% for all systems. New experimental data on enzymatic esterification of crude citronella essential oil for geranyl and citronellyl esters production in solvent-free system are reported in this work.
Assuntos
Cymbopogon/química , Aromatizantes/síntese química , Óleos Voláteis/química , Esterificação , Solventes/químicaRESUMO
The main objective of this work is to present the optimization of the biotransformation of R-(+)-limonene and (-)-ß-pinene aiming at the production of α-terpineol by strains of fungal and yeasts previously isolated by our research group using the methodology of experimental design. New optimized experimental data on α-terpineol production by the biotransformation of R-(+)-limonene and (-)-ß-pinene using newly isolated microorganisms are reported in this work. Conversion of about 1,700 mg/L was achieved when R-(+)-limonene was used as substrate and the newly isolated strain 05.01.35 as microorganism at the central point of the experimental design, corresponding to a substrate concentration of 1.75%, mass of inoculum of 2 g, and substrate to ethanol volume ratio of 1:1. The same experimental condition led to higher conversions when (-)-ß-pinene was used as substrates and the strains coded as 04.05.08 and 01.04.03 as microorganism. Here, conversions of about 770 mg/L were achieved.
Assuntos
Compostos Bicíclicos com Pontes/química , Cicloexenos/química , Cicloexenos/metabolismo , Monoterpenos/química , Monoterpenos/metabolismo , Terpenos/química , Aspergillus/metabolismo , Monoterpenos Bicíclicos , Biodegradação Ambiental , Compostos Bicíclicos com Pontes/metabolismo , Monoterpenos Cicloexânicos , Limoneno , Estereoisomerismo , Terpenos/metabolismoRESUMO
This work reports the optimization of geranyl propionate production by esterification of geraniol and propionic acid in a solvent-free system using a commercial lipase as catalyst. For this purpose, a sequential strategy was performed applying two experimental designs. The operating conditions that optimized geranyl propionate production were determined to be 40 °C, geraniol to propionic acid molar ratio of 3:1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the optimum reaction parameters, a kinetic study was carried out evaluating the influence of substrates molar ratio, enzyme concentration and temperature on reaction conversion. Results obtained in this step allow to conclude that an excess of alcohol (acid to alcohol molar ratio of 1:6), relatively low enzyme concentration (5 wt%), temperature of 40 °C and substrates molar ratio of 1:1 afforded nearly complete reaction conversion after 30 min of reaction. New experimental data on enzymatic esterification of geraniol and propionic acid for geranyl propionate production are reported in this work, showing a promising perspective of the technique to overcome the well-known drawbacks of the chemical-catalyzed route.
Assuntos
Lipase/metabolismo , Ácidos Oleicos/síntese química , Propionatos/síntese química , Propionatos/metabolismo , Solventes/química , Terpenos/metabolismo , Monoterpenos Acíclicos , Biotecnologia , Catálise , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Esterificação , Proteínas Fúngicas , Cinética , Lipase/química , Ácido Oleico/síntese química , Propionatos/química , Temperatura , Terpenos/químicaRESUMO
The aim of this work was to perform the screening of microorganisms, previously isolated from samples of agro-industrial waste and belonging to the culture collection of our laboratory, able to produce polygalacturonases (PG). A total of 107 microorganisms, 92 newly isolated and 15 pre-identified, were selected as potential producers of enzymes with PG activity. From these microorganisms, 20 strains were able to synthesize PG with activities above 3 U mL(-1). After the kinetic study, the enzyme activity was increased up to 13 times and the microorganism identified as Aspergillus niger ATCC 9642 and the newly isolated W23, W43, and D2 (Penicillium sp.) after 24 h of fermentation led to PG activities of 30, 41, 43, and 45 U mL(-1), respectively. The RAPD analysis demonstrated that the selected strains differs genetically, indicating that no duplication of strains among them in the experiments for polygalacturonases production was verified.
Assuntos
Fungos/enzimologia , Poligalacturonase/biossíntese , Poligalacturonase/metabolismo , Fermentação , Fungos/genética , Fungos/isolamento & purificação , Concentração de Íons de Hidrogênio , Filogenia , Fatores de TempoRESUMO
This study reports the maximization of geranyl oleate production by esterification of geraniol and oleic acid in a solvent-free system using a commercial lipase as catalyst. The operating conditions that maximized geranyl oleate production were determined to be 40 °C, geraniol to oleic acid molar ratio of 5:1, 150 rpm and 10 wt% of enzyme, with a resulting reaction conversion of about 93%. After determining the best reaction parameters, a kinetic study was performed and the results obtained in this step allow to conclude that an excess of alcohol (alcohol to acid molar ratio of 5:1), relatively low enzyme concentration (5 wt%) and temperature of 50 °C afforded nearly complete reaction conversion after 1 h of reaction. New experimental data on enzymatic esterification of geraniol and oleic acid for geranyl oleate production are reported in this work, showing a promising perspective of the technique to overcome the inconvenience of the chemical-catalyzed route.
Assuntos
Lipase/metabolismo , Ácidos Oleicos/síntese química , Ácidos Oleicos/metabolismo , Solventes/química , Monoterpenos Acíclicos , Biotecnologia , Catálise , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Esterificação , Proteínas Fúngicas , Cinética , Lipase/química , Ácidos Oleicos/química , Temperatura , Terpenos/química , Terpenos/metabolismoRESUMO
Verbenol is a bicyclicbicycle secondary allylic alcohol, with pronounced camphor and mint flavor notes, mainly used as food flavoring. This compound is also used to control harmful insects, and hence has potential for using in agriculture, and is an intermediate in the synthesis of valuable perfume and medicinal substances. This work is focused on the microbial oxidation of (-)-α-pinene to verbenol production. To carry out the present study, 405 microorganisms were tested for their ability to bioconvert the substrate. From the isolated microorganisms, 193 were selected in the pre-screening using mineral medium for limonene degradation. At the screening step, 31 strains were able to convert (-)-α-pinene in verbenol. The highest concentration in verbenol from (-)-α-pinene was about 125.6 mg/L for yeast isolated from orange juice industrial residue.
Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Fungos/isolamento & purificação , Fungos/metabolismo , Monoterpenos/metabolismo , Bebidas/microbiologia , Monoterpenos Bicíclicos , Biotransformação , Citrus/microbiologia , Indústria Alimentícia , Cinética , OxirreduçãoRESUMO
This work investigated the influence of temperature, enzyme concentration, substrates molar ratio, in the absence and presence of organic solvent, at two molar ratios of the substrates on the enzymatic production of linalil esters using the immobilized lipase Novozym 435 as catalyst, different acids and linalool and Ho-Sho essential oil as substrates. The best reaction conversion was obtained at the highest temperature (70 degrees C), for both solvent free (3.81%) and with solvent addition (2.25%), for a solvent to substrates molar ratio of 2:1, enzyme concentration of 5 wt% and acid to alcohol molar ratio of 1:1. The reaction kinetics revealed that Ho-Sho essential oil afforded the greatest conversions when compared with pure linalool. Higher linalil esters production were achieved after 10 h reaction (5.58%) in 2:1 solvent to substrates molar ratio, with enzyme concentration of 5 wt%, at 70 degrees C and anhydride to alcohol molar ratio of 1:1 using Ho-Sho essential oil as substrate.
Assuntos
Candida/enzimologia , Proteínas Fúngicas/química , Lipase/química , Monoterpenos/síntese química , Solventes/química , Monoterpenos Acíclicos , Enzimas Imobilizadas , Ésteres , Monoterpenos/químicaRESUMO
This work is focused on the biotransformation of R-(+)-limonene and (-)-beta-pinene to bioflavor production. To carry out the present study, 405 microorganisms were tested for their ability to bioconvert the substrates. From the isolated microorganisms, 193 were selected in the prescreening using mineral medium for limonene degradation. At the screening step, eight strains were able to convert R-(+)-limonene and 15 to transform (-)-beta-pinene, both in alpha-terpineol. The highest concentration in alpha-terpineol from R-(+)-limonene was about 3,450 mg/L for Penicillium sp. isolated from eucalyptus steam. From (-)-beta-pinene, the highest product concentration of 675.5 mg/L was achieved using an Aspergillus sp. strain isolated from orange tree stem.
Assuntos
Compostos Bicíclicos com Pontes/metabolismo , Cicloexenos/metabolismo , Monoterpenos/metabolismo , Terpenos/metabolismo , Aspergillus/metabolismo , Monoterpenos Bicíclicos , Monoterpenos Cicloexânicos , Limoneno , Penicillium/metabolismoRESUMO
This work aimed to evaluate the effects of particle size, solid/solvent ratio (w/v), and reaction time on hydrolytic and esterification activities of a lipase extract from wheat seeds. The higher hydrolytic activity was 5.9 U/g with a particle size of 425 microm, solid/solvent ratio of 30:60 (w/v), and reaction time of 15 h, with maximum hydrolytic activity of 14.47 U/g after 24 h of precipitation. For esterification activity the best result was 57.88 U/g with a particle size of 425 microm and solid/solvent ratio of 30:120 (w/v) for 5 h, with a maximum value after 10 h of precipitation reaching 208.20 U/g. The partial characterization showed that the optimal pH and temperature were found to be 5.5 and 32-37 degrees C, respectively. The extract stability at low temperatures was kept after 48 h of storage in terms of esterification activity. The hydrolytic activity was kept constant at -10 degrees C during 72 h and diminished considerably after 24 h at 4 degrees C.
Assuntos
Fracionamento Químico/métodos , Lipase/isolamento & purificação , Proteínas de Plantas/isolamento & purificação , Triticum/enzimologia , Acetona/química , Esterificação , Concentração de Íons de Hidrogênio , Hidrólise , Lipase/química , Tamanho da Partícula , Proteínas de Plantas/química , Sementes/química , Sementes/enzimologia , Temperatura , Triticum/químicaRESUMO
The use of microorganisms for biotransformations of monoterpenes has stimulated the biotechnological market. Aiming at the highest efficiency in the process of strains screening, the application of molecular biology techniques have been proposed. Based on these aspects, the objective of this work was to select different strains able to convert limonene using fermentative process and random amplified polymorphic DNA (RAPD) markers. The results obtained in the fermentative screening, from 17 strains tested, pointed out that four microorganisms were able to convert limonene into oxygenated derivatives. The RAPD study showed a polymorphism of 96.02% and a similarity from 16.02 to 51.51%. Based on this it was possible to observe a high genetic diversity, even among strains of same species, concluding that the RAPD was not able to correlate the genetic characteristics of the microorganism with the results obtained from the biotransformation process.
Assuntos
Bactérias/isolamento & purificação , Bactérias/metabolismo , Citrus/microbiologia , Terpenos/metabolismo , Bactérias/genética , Biotransformação , Cicloexenos , Marcadores Genéticos/genética , Limoneno , Técnica de Amplificação ao Acaso de DNA Polimórfico , Especificidade da EspécieRESUMO
This work is focused on the chemical characterization of Maytenus ilicifolia extracts obtained from high-pressure CO2 extraction. The experiments were performed in a laboratory-scale unit, where the effect of particle size (35-200 mesh), CO2 mass flow rate (1-3 g/min), temperature (293-323 K), pressure (100-250 bar), and extraction time was investigated in terms of liquid yield and chemical composition of the extracts. Results show that the particle size and CO2 mass flow rate did not affect the liquid yield, whereas the extraction temperature and solvent density exerted a pronounced effect on both liquid yield and chemical distribution of volatile compounds. The extracts were chemically analyzed with regard to phytol, squalene, vitamin E, stigmasterol, friedelan-3-ol, friedelin, dodecanoic acid and geranyl acetate in a GC/MSD.