Polyethylene glycol (PEG) is polymer that was used to replace NaCl (reference media) as an osmotic stress agent for the synthesis of erythritol by the osmophilic yeast
Yarrowia lipolytica
. Two ...strains, the wild-type strain IMUFRJ 50682 and the lab strain W29, were grown in the presence of PEG of different molecular weights. For strain IMUFRJ 50682, the erythritol titer was increased by 40% in the presence of PEG2000 as compared to the reference media (with NaCl). A similar increase was also observed for strain W29, except that it occurred in the presence of PEG6000. Moreover, in those experimental conditions neither strain produced mannitol, in contrast to the control medium. These results highlight that PEG could be used to increase erythritol productivity and to simultaneously inhibit mannitol synthesis, representing a good substitute for NaCl as an osmotic stress agent.
Nitrogen-limiting condition is essential for citric acid production by
Yarrowia lipolytica
. Mitochondrial protein expression profiles of
Y. lipolytica
IMUFRJ 50,682 cells cultivated in biomass ...proliferation medium (YPG medium, yeast extract, peptone and glycerol) and citric acid production medium (CA medium) were analyzed to identify differences in expressed proteins in response to medium composition. The identification of 45 proteins in mitochondria of YPG medium cells and 48 proteins in mitochondria of CA medium cells were possible with proteomic analyses. Only 11 proteins were common to both conditions, showing a different expression pattern in relation to limiting and non-limiting nitrogen conditions. For both conditions, most proteins (52%—CA medium, 46%—YPG medium) were related to energy metabolism. CA medium cells expressed more carbohydrate metabolism proteins (six proteins) then YPG medium cells (three proteins) and the opposite was detected for translation proteins.
A synthetic medium containing glucose, glycerol, yeast extract (YE), and ammonium sulfate (AS) was compared to several low-cost media in their ability to produce high emulsification index (EI). The ...goal was to reduce the production costs of an emulsifier with application in food oil-in-water emulsions. To this end, agro-industrial by-products were screened for bioemulsifier production from Yarrowia lipolytica. The statistical analysis showed that the EIs of media containing residual frying oil from palm oil (RFO_palm) or soybean oil (RFO_soy), residual liquid from butter production (butter whey, BWhey) or cheese production (cheese whey, CWhey), supplemented with YE and AS were similar to the EI of the synthetic medium. The replacement of YE by corn steep liquor (CSL) also resulted in similar EI, except for RFO_soy. BWhey was tested with CSL without AS and similar EI (66.8%) was detected in comparison to that of the same medium with AS (66.3%). The cell-free broth obtained after Y. lipolytica growth in BWhey+CSL was successfully used to obtain vegetable oil-in-water emulsions indicating its potential application in food products.
RESUMO: O meio sintético contendo glicose, glicerol, extrato de levedura (YE) e sulfato de amônio (AS) foi comparado a meios de baixo custo para produzir alto índice de emulsificação (EI). Para este fim, os subprodutos agroindustriais foram rastreados quanto à produção de bioemulsificante por Yarrowia lipolytica. A análise estatística mostrou que EI de meios contendo óleo de fritura residual de óleo de palma (RFO_palm) ou óleo de soja (RFO_soy), líquido residual da produção de manteiga (soro de manteiga, BWhey) ou da produção de queijo (soro de queijo, CWhey), suplementado com YE e AS foram semelhantes ao EI do meio sintético. A substituição do YE por milhocina (CSL) também resultou em EI semelhante, exceto no RFO_soy. O BWhey foi testado com CSL sem AS e EI semelhante (66,8%) foi detectado em comparação com o mesmo meio com AS (66,3%). O meio isento de células obtido após o crescimento de Y. lipolytica no meio BWhey + CSL foi utilizado com sucesso para obter emulsões de óleo vegetal em água, indicando sua potencial aplicação em produtos alimentícios.
The aim of the present study was to compare two nanoparticle composition loaded with Brazilian red propolis extract regarding its physicochemical characteristics and its antioxidant and ...antileishmanial activities. The red propolis nanoparticles in an aqueous medium and in solid-state presented particle size in a nanometric scale with an apparent size of 100-288 nm for the NEPE and 175-380 nm for the NPPE. ATR-FTIR and thermal analysis revealed an encapsulation of flavonoids from the red propolis extract in polymeric matrices for the multidrug delivery system. UPLC-DAD identified red propolis markers (flavonoids) in EPE, NEPE and NPPE. The efficiency of encapsulation (28.0-55.0% for NEPE and 61.2-81.0% for NPPE) were determined and calculated using UPLC-DAD. DPPH method showed the antioxidant activity of both EPE and nanoparticle compositions of red propolis. These polymeric matrices systems were able to encapsulate flavonoids from red propolis extract with specific characteristics of solubility and polarity. EPE and nanoparticles loaded with red propolis extract in the multi-constituent co-delivery system presented leishmanicidal activity and a good correlation was established between IC
50
and efficiency of encapsulation. Red propolis nanoparticles exhibited leishmanicidal activity but NEPE presented a lower leishmanicidal effect in relation to NPPE, which showed similar activity compared to EPE. The nanopolymeric matrices choice should be established in propolis nanoparticle compositions to avoid lack of efficacy of bioproducts. Red propolis nanoparticles were shown to be a potential final bulk product for the preparation of various pharmaceutical and cosmetics compositions in therapy against diseases such as leishmaniasis.
Scanning Electron Microscopy of red propolis nanoparticles (NEPE 30) (A). ATR-FTIR spectra of NPPE 30 and NPPE placebo (B). Chromatogram of the NPPE 30 (C). Determination of IC using leishmanicidal assay against Leishmania braziliensis for EPE, NEPE and NPPE (D).
The ever-increasing demand for natural products and biotechnology derived from bees and ultra-modernization of various analytical devices has facilitated the rational and planned development of ...biotechnology products with a focus on human health to treat chronic and neglected diseases. The aim of the present study was to prepare and characterize polymeric nanoparticles loaded with Brazilian red propolis extract and evaluate the cytotoxic activity of “multiple-constituent extract in co-delivery system” for antileishmanial therapies. The polymeric nanoparticles loaded with red propolis extract were prepared with a combination of poly-ε-caprolactone and pluronic using nanoprecipitation method and characterized by different analytical techniques, antioxidant and leishmanicidal assay. The red propolis nanoparticles in aqueous medium presented particle size (200–280 nm) in nanometric scale and zeta analysis (−20 to −26 mV) revealed stability of the nanoparticles without aggregation phenomenon during 1 month. After freeze-drying method using cryoprotectant (sodium starch glycolate), it was possible to observe particles with smooth and spherical shape and apparent size of 200 to 400 nm. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and thermal analysis revealed the encapsulation of the flavonoids from the red propolis extract into the polymeric matrix. Ultra performance liquid chromatography coupled with diode array detector (UPLC-DAD) identified the flavonoids liquiritigenin, pinobanksin, isoliquiritigenin, formononetin and biochanin A in ethanolic extract of propolis (EEP) and nanoparticles of red propolis extract (NRPE). The efficiency of encapsulation was determinate, and median values (75.0 %) were calculated using UPLC-DAD. 2,2-Diphenyl-1-picryhydrazyl method showed antioxidant activity to EEP and red propolis nanoparticles. Compared to negative control, EEP and NRPE exhibited leishmanicidal activity with an IC50 value of ≅38.0 μg/mL and 31.3 μg/mL, 47.2 μg/mL, 154.2μg/mL and 193.2 μg/mL for NRPE A1, NRPE A2, NRPE A3 and NRPE A4, respectively. Nanoparticles loaded with red propolis extract in co-delivery system and EEP presented cytotoxic activity on
Leishmania (V.) braziliensis
. Red propolis extract loaded in nanoparticles has shown to be potential candidates as intermediate products for preparation of various pharmaceutical dosage forms containing red propolis extract in the therapy against negligible diseases such as leishmaniasis.
Graphical Abstract
Some biochemical mechanisms of cellular debridement of
Leishmania (V.) braziliensis
species by the flavonoids of red propolis extract (EEP) or NRPE loaded with red propolis extract
Lipase activity (337 U/g dry weight of cell debris) was detected in cell debris after ultrasound treatment of
Yarrowia lipolytica
cells cultivated in residual frying palm oil. It is a naturally ...immobilized lipase with protein content of 47%, herein called LipImDebri. This immobilized biocatalyst presents low hydrophobicity (8%), that can be increased adjusting pH and buffer type. Despite apparent intact cells, electron microscopy showed a shapeless and flat surface for LipImDebri and optical microscopy revealed no cell viability. Besides, an inferior mean diameter (3.4 mm) in relation to whole cells reveals structure modification. A high negative zeta potential value (− 33.86 mV) for pH 6 and 25 °C suggests that LipImDebri is a stable suspension in aqueous solution. Fourier Transform Infrared Spectra (FTIR) expose differences between LipImDebri and extracellular lipase extract signaling a physical interaction between enzyme and cell debris, which is possibly the reason for the high thermostability (
k
d
= 0.246 h
−1
;
t
1/2
= 2.82 h at 50 °C, pH 7.0). A good adjustment of LipImDebri kinetic data with Hill equation (
R
2
= 0.95) exposes an allosteric behavior related to the presence of more than one lipase isoform. These features reveal that LipImDebri can be a good catalyst for industrial applications.
Resumo O uso de simuladores na educação médica tem sido cada vez mais frequente, porém pouco acessíveis devido ao custo elevado. Foi desenvolvido para tal um modelo acessível e de baixo custo para o ...aprendizado e o treinamento de suturas e anastomoses vasculares em Laboratório de Bases das Técnicas Cirúrgicas. Foram utilizados balões de látex de cores variadas, fio de polipropileno 6.0 e outros materiais específicos para sutura vascular (porta-agulhas e pinças). Para facilitar o reparo dos balões, eles foram fixados em parafusos sobre placas de madeira. Foram feitas anastomoses terminoterminal, terminolateral e laterolateral e construção de patch. A perviedade da anastomose foi testada a partir da injeção de água em uma extremidade do balão e a observação da saída do conteúdo líquido na extremidade oposta. As vantagens observadas nesse modelo de treinamento para anastomoses foram a maleabilidade, a resistência à passagem do fio e o fato de ser inorgânico. Os balões de látex são uma alternativa barata, viável, não perecível e de uso prolongado no ensino e treinamento das suturas e anastomoses arteriais.
Resumo Contexto A redução das dificuldades no aprendizado da técnica cirúrgica levou ao surgimento de ferramentas complementares. Este trabalho descreve a curva de aprendizado dos alunos sujeitos da ...pesquisa, utilizando um modelo alternativo para a prática de anastomose vascular. Objetivos Avaliar a curva de aprendizado da técnica de anastomose vascular e do desenvolvimento de habilidades manuais a partir da utilização de um modelo experimental de baixo custo. Métodos Este trabalho é um estudo experimental e prospectivo, com a realização de anastomoses vasculares do tipo terminolateral em balões de látex durante cinco fases sucessivas, iniciadas após orientação teórico-prática de uma cirurgiã vascular experiente. Os sujeitos foram seis graduandos do curso de Medicina, do terceiro ao quinto ano, da Universidade Federal da Paraíba (UFPB), João Pessoa, Paraíba, Brasil. A interpretação do material coletado acerca da qualidade das anastomoses e do tempo utilizado seguiu a análise de agrupamento. Resultados Houve redução do tempo de realização das anastomoses de todos os alunos, com diferença estatística da fase 1 quando comparada às fases 4 e 5, bem como tendência crescente no índice de qualidade ao longo das fases. Porém, não foi detectada diferença estatística a partir do teste de Friedman, apropriado para dados com nível de mensuração ordinal (escala de 1 a 5 na avaliação da qualidade). Conclusões O modelo de treinamento utilizado foi efetivo para incremento do aprendizado dessa técnica, acreditando-se que amostras de maior tamanho ou com maior número de fases em trabalhos futuros poderiam demonstrar redução do tempo associada a melhora da qualidade da anastomose realizada com significância estatística.
Abstract Background In order to reduce difficulties with learning surgical techniques, supplementary tools for training were developed. This paper describes the learning curve followed by student volunteer research subjects who used an alternative model for practicing vascular anastomosis. Objectives To evaluate the vascular anastomosis technique learning curve and development of manual skills using a low-cost experimental model. Methods Experimental and prospective study using end-to-side vascular anastomosis in latex balloons over five successive phases, initiated after theoretical and practical guidance given by experienced vascular surgeon. The study subjects were six undergraduate medical students from Universidade Federal da Paraíba (UFPB), João Pessoa, PB, Brazil, in their third to fifth years of the course. Cluster analysis was used to interpret the data collected on the quality of anastomoses and the time taken. Results The time taken to perform anastomosis reduced for all students, with statistical differences from phase 1 compared to phases 4 and 5. There was also a trend to increasing scores on the quality index as the phases progressed. However, no statistical differences were detected using the Friedman test, which is appropriate for data measured with ordinal levels (quality was assessed on a scale of 1 to 5). Conclusions It was found that the training model used was effective for increasing learning of this technique. It is believed that future studies with larger samples or a higher number of phases could demonstrate both reduced time and improved quality of the anastomoses performed with statistical significance.
Simulators are increasingly being used in medical education, but accessibility is restricted by their elevated cost. A accessible and low-cost model was developed for teaching and learning vascular ...sutures and anastomoses at a Basic Surgical Techniques Laboratory. Latex balloons of varying colors, polypropylene 6.0 sutures, and other materials specifically for suturing (needle holder and forceps) were used. The balloons were fixed to screws inserted into wooden boards in order to facilitate repairs. E end-to-end, end-to-side, and side-to-side anastomoses and patching were performed. Anastomosis patency was tested by injecting water into one extremity of the balloon and observing the liquid exit via the opposite extremity. The advantages observed with this training model for anastomoses were malleability, resistance to passage of the suture, and the fact that it is inorganic. Latex balloons are an inexpensive option that are non‑perishable and offer prolonged use for teaching and practice of arterial sutures and anastomoses.
Resumo O uso de simuladores na educação médica tem sido cada vez mais frequente, porém pouco acessíveis devido ao custo elevado. Foi desenvolvido para tal um modelo acessível e de baixo custo para o ...aprendizado e o treinamento de suturas e anastomoses vasculares em Laboratório de Bases das Técnicas Cirúrgicas. Foram utilizados balões de látex de cores variadas, fio de polipropileno 6.0 e outros materiais específicos para sutura vascular (porta-agulhas e pinças). Para facilitar o reparo dos balões, eles foram fixados em parafusos sobre placas de madeira. Foram feitas anastomoses terminoterminal, terminolateral e laterolateral e construção de patch. A perviedade da anastomose foi testada a partir da injeção de água em uma extremidade do balão e a observação da saída do conteúdo líquido na extremidade oposta. As vantagens observadas nesse modelo de treinamento para anastomoses foram a maleabilidade, a resistência à passagem do fio e o fato de ser inorgânico. Os balões de látex são uma alternativa barata, viável, não perecível e de uso prolongado no ensino e treinamento das suturas e anastomoses arteriais.
Abstract Simulators are increasingly being used in medical education, but accessibility is restricted by their elevated cost. A accessible and low-cost model was developed for teaching and learning vascular sutures and anastomoses at a Basic Surgical Techniques Laboratory. Latex balloons of varying colors, polypropylene 6.0 sutures, and other materials specifically for suturing (needle holder and forceps) were used. The balloons were fixed to screws inserted into wooden boards in order to facilitate repairs. E end-to-end, end-to-side, and side-to-side anastomoses and patching were performed. Anastomosis patency was tested by injecting water into one extremity of the balloon and observing the liquid exit via the opposite extremity. The advantages observed with this training model for anastomoses were malleability, resistance to passage of the suture, and the fact that it is inorganic. Latex balloons are an inexpensive option that are non‑perishable and offer prolonged use for teaching and practice of arterial sutures and anastomoses.
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