Antithrombotic and anticariogenic activity of peptide fractions from cowpea (Vigna unguiculata) protein hydrolysates.

BACKGROUND: Protein-derived peptide fractions can play a key role in the physiological and metabolic regulation and modulation of the body, which suggests that they could be used as functional ingredients to improve health and to reduce the risk of disease. This work aimed to evaluate the in vitro antithrombotic and anticariogenic bioactivity of hydrolysates and protein fractions obtained from cowpea (Vigna unguiculata) by biocatalysis. RESULTS: Cowpea protein concentrate was hydrolyzed by sequential action with two enzyme systems, Pepsin-Pancreatin or Alcalase-Flavourzyme. There was extensive enzymatic hydrolysis, with degrees of hydrolysis of 34.94% and 81.43% for Pepsin-Pancreatin and Alcalase-Flavourzyme, respectively. The degree of hydrolysis for the control treatments, without the addition of the enzymes Pepsin-Pancreatin and Alcalase-Flavourzyme was 1.1% and 1.2%, respectively. The hydrolysates were subjected to fractionation by ultrafiltration, with five cut-off points according to molecular weight (<1, 1-3, 3-5, 5-10 and >10 kDa). The Alcalase-Flavourzyme hydrolysate led to 100% inhibition of platelet aggregation, while the Pepsin-Pancreatin hydrolysate showed 77.41% inhibition, but this was approximately 100% in the ultrafiltered fractions. The highest anticariogenic activity was obtained with the Pepsin-Pancreatin system, with 61.55% and 56.07% for calcium and phosphorus demineralization, respectively. CONCLUSION: Hydrolysates and their peptide fractions from Vigna unguiculata exhibited inhibition of platelet aggregation and protection of tooth enamel and have the potential for use in the development of functional products with beneficial health effects. © 2024 Society of Chemical Industry.

Antioxidant and antibacterial properties of ethanolic pot-pollen extract of Melipona beecheii and determination of the major components by GC-MS.

Melipona beecheii pot-pollen is a natural product that has barely been studied, unlike other hive products such as honey and propolis. Its application has been reported since ancient times in traditional Mayan medicine, and it is also a functional food with high nutritional value. In the present study, samples of ethanolic pot-pollen extracts from five locations in the Yucatán Peninsula were analyzed to determine their antibacterial and antioxidant properties. All the extracts showed activity against five medically important bacteria; Pseudomonas aeruginosa and Listeria monocytogenes were the most susceptible bacteria in all samples. The evaluated antioxidant activity was higher than that reported by other studies. Palmitic, linoleic, and linolenic fatty acids and their respective ethyl ethers were detected by Gas Chromatography-Mass Spectrometry (GC-MS) in all samples in different concentrations. Based on these results, pot-pollen extract from Mama, Yucatán exhibited the best biological activities (Minimum Inhibitory Concentrations (MICs) between 6 and 40 mg/mL, EC50 DPPH 28 µg/mL, EC50 RP 30 µg/mL), which could be related to a higher content of unsaturated fatty acids and their ethyl esters. The present study demonstrates that M. beecheii pot-pollen has therapeutic potential in addition to its benefits as a nutritional supplement.

Tailoring Heat Transfer and Bactericidal Response in Multifunctional Cotton Composites.

Through the execution of scientific innovations, "smart materials" are shaping the future of technology by interacting and responding to changes in our environment. To make this a successful reality, proper component selection, synthesis procedures, and functional active agents must converge in practical and resource-efficient procedures to lay the foundations for a profitable and sustainable industry. Here we show how the reaction time, temperature, and surface stabilizer concentration impact the most promising functional properties in a cotton-based fabric coated with silver nanoparticles (AgNPs@cotton), i.e., the thermal and bactericidal response. The coating quality was characterized and linked to the selected synthesis parameters and correlated by a parallel description of "proof of concept" experiments for the differential heat transfer (conversion and dissipation properties) and the bactericidal response tested against reference bacteria and natural bacterial populations (from a beach, cenote, and swamp of the Yucatan Peninsula). The quantification of functional responses allowed us to establish the relationship between (i) the size and shape of the AgNPs, (ii) the collective response of their agglomerates, and (iii) the thermal barrier role of a surface modifier as PVP. The procedures and evaluations in this work enable a spectrum of synthesis coordinates that facilitate the formulation of application-modulated fabrics, with grounded examples reflected in "smart packaging", "smart clothing", and "smart dressing".

Antimicrobial and antioxidant activity of proteins isolated from Melipona beecheii honey.

Proteins from Melipona beecheii honey were purified by concanavalin A (conA) affinity chromatography and eluted with a stepwise glucose gradient into fractions named F2-F5. The conA-unbound fraction (F1) was further separated by molecular exclusion into fractions named MbF1-1,2 and MbF1-3. All fractions were evaluated for antibacterial activity against foodborne pathogens and antioxidant capacity. F1 fraction possessed highest antimicrobial activity against S. aureus, L. monocytogenes, S. Typhimurium, E. coli and P. aeruginosa with MIC's 1.4 ± 0.2, 15 ± 1, 39 ± 2, 1 ± 0.1, and 75 ± 2 µg/mL, respectively. F1, MbF1-1,2 and MbF1-3 had bactericidal effect except against P. aeruginosa. When the antioxidant capacity of the fractions was determined, F2 had the highest antioxidant activity measured by DPPH radical scavenging activity (IC50 = 2.4 ± 0.4 µg/µL) and reducing power of Fe(III) (IC50 = 1.8 ± 0.2 µg/µL). We provide evidence that M. beecheii honey proteins possess broad spectrum antibacterial and antioxidant activity, the latter probably through their reducing agent and free radical scavenger properties.

Tratamiento con sildenafilo en disfunción ventricular izquierda e hipertensión pulmonar asociada / Treatment with sildenafil in left ventricular dysfunction and associated pulmonary hypertension

RESUMEN Introducción: la hipertensión pulmonar es un hallazgo frecuente en la insuficiencia cardíaca. El uso del sildenafilo en estos casos es una práctica habitual, pero aún controversial por lo limitado de los estudios realizados. Objetivo: comparar las variables ecocardiográficas de hemodinamia pulmonar, en pacientes con disfunción sistólica ventricular izquierda e hipertensión pulmonar secundaria severa, antes y después del uso del sildenafilo. Materiales y métodos: se realizó un estudio de cohorte, donde se incluyeron 19 pacientes; se realizó un seguimiento de dos años. Se analizaron variables clínicas, de laboratorio y ecocardiográficas. Se evaluaron las principales variables de hemodinamia pulmonar antes del uso del sildenafilo y a las doce semanas de su indicación. Se realizó una curva de supervivencia al concluir el seguimiento. El nivel de significación estadístico empleado fue de p < 0,05. Resultados: la edad promedio fue de 56,16 ± 15,77 años y predominó el sexo masculino, con un 73,7 %. La supervivencia al término del seguimiento fue de 78,9 %. Las principales variables ecocardiográficas de hemodinamia pulmonar mostraron una reducción significativa a las doce semanas del tratamiento con sildenafilo. La supervivencia de los pacientes con una reducción del 25 % de las presiones pulmonares en el ecocardiograma realizado a las doce semanas del tratamiento, fue mayor al terminar el estudio (100 % vs 33 %, log-rank test p = 0,001). Conclusiones: posterior al uso del sildenafilo se encontró una reducción significativa de las variables de hemodinamia pulmonar en el ecocardiograma evolutivo. La sobrevida fue mayor en los pacientes que presentaron dicha reducción (AU).

ABSTRACT Introduction: pulmonary hypertension is a common finding in heart failure. The use of sildenafil in these cases is a common practice, but still controversial due to the limited number of studies carried out. Objective: to compare echocardiographic variables of pulmonary hemodynamics, in patients with left ventricular systolic dysfunction and severe secondary pulmonary hypertension, before and after the use of sildenafil. Materials and methods: a cohort study was led, including 19 patients; a two-year follow-up was carried out. Clinical, laboratory and echocardiographic variables were analyzed. The main pulmonary hemodynamics variables were evaluated before the use of sildenafil and 12 weeks after its indication. A survival curve was performed at the end of the follow-up. The statistical significance level used was p < 0.05. Results: the average age was 56.16 ± 15.77 years, and male sex predominated with 73.3 %. Survival at the end of the follow up was 78.9 %. The main echocardiographic variables of pulmonary hemodinamics showed a significant reduction at 12 weeks of treatment with sildenafil. The survival of patients with a 25 % reduction in pulmonary pressures in the echocardiogram performed at 12 weeks of treatment was greater at the end of the study (100 % vs 33 %, log-rank test p = 0.001). Conclusions: after using sildenafil, a significant reduction of pulmonary hemodynamics variables was found in the evolutionary echocardiogram. Survival was higher in patients who had this reduction (AU).

Obtainment and Characterization of Hydrophilic Polysulfone Membranes by N-Vinylimidazole Grafting Induced by Gamma Irradiation.

Polysulfone (PSU) film and N-vinylimidazole (VIM) were used to obtain grafted membranes with high hydrophilic capacity. The grafting process was performed by gamma irradiation under two experiments: (1) different irradiation doses (100-400 kGy) and VIM 50% solution; (2) different concentration of grafted VIM (30-70%) and 300 kGy of irradiation dose. Characteristics of the grafted membranes were determined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), contact angle, swelling degree, desalination test, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Both experiments indicated that the absorbed dose 300 kGy and the VIM concentration, at 50% v/v, were effective to obtain PSU grafted membranes with 14.3% of grafting yield. Nevertheless, experimental conditions, 400 kGy, VIM 50% and 300 kGy, VIM 60-70% promoted possible membrane degradation and VIM homopolymerization on the membrane surface, which was observed by SEM images; meanwhile, 100-200 kGy and VIM 30-50% produced minimal grafting (2 ± 0.5%). Hydrophilic surface of the grafted PSU membranes by 300 kGy and VIM 50% v/v were corroborated by the water contact angle, swelling degree and desalination test, showing a decrease from 90.7° ± 0.3 (PSU film) to 64.3° ± 0.5; an increment of swelling degree of 25 ± 1%, and a rejection-permeation capacity of 75 ± 2%. In addition, the thermal behavior of grafted PSU membranes registered an increment in the degradation of 20%, due to the presence of VIM. However, the normal temperature of the membrane operation did not affect this result; meanwhile, the glass transition temperature (Tg) of the grafted PSU membrane was found at 185.4 ± 0.5 °C, which indicated an increment of 15 ± 1%.

Supervivencia a los cinco años en pacientes con valvulopatías izquierdas operados de cirugía cardíaca valvular / Five-year survival of patients with left-side heart valve disease who underwent heart valve surgery

RESUMEN Introducción: La supervivencia a mediano y largo plazo es un parámetro necesario para evaluar los resultados de la cirugía valvular cardíaca. Objetivos: Determinar la supervivencia a los cinco años de los pacientes operados de cirugía cardíaca valvular aórtica, mitral o ambas, y las variables que pueden pronosticar de manera independiente una peor sobrevida en el seguimiento. Método: Se realizó un estudio de cohorte que evaluó a los 139 pacientes operados de cirugía cardíaca valvular en el trienio 2010-2012, en el Instituto de Cardiología y Cirugía Cardiovascular de La Habana, Cuba, y que fueron egresados vivos del postoperatorio, hasta un período de cinco años posteriores a la intervención. Se realizó una curva de Kaplan Meier para determinar la supervivencia al final del seguimiento, así como un análisis multivariable de Cox para determinar las variables que se asociaron a una menor supervivencia. El nivel de significación estadística empleado fue p<0,05. Resultados: La muestra resultó homogénea según las variables clínicas y demográficas. La supervivencia al término del seguimiento, que tuvo una media de 5,8 años, fue de un 93%. El incremento de la edad (HR=1,15; p=0,001) y el haber sufrido bajo gasto cardíaco durante el perioperatorio (HR=3,54; p=0,037) se asociaron de manera independiente a una peor sobrevida en el seguimiento. Conclusiones: La supervivencia de los pacientes al concluir el seguimiento fue elevada. El incremento de la edad y el bajo gasto cardíaco perioperatorio fueron las variables asociadas de manera independiente a una menor sobrevida.

ABSTRACT Introduction: The mid and long term survival rate is a necessary parameter to evaluate the outcomes of heart valve surgery. Objectives: To determine the five-year survival of patients who underwent aortic and/or mitral valve surgery, and the variables that could independently predict a lower survival in the follow-up. Method: A cohort study was conducted for evaluating 139 patients who underwent a heart valve surgery, in the period 2010-2012, at the Instituto de Cardiología y Cirugía Cardiovascular of Havana, Cuba, all of which survived the postoperative period, and were followed up to five years after the surgery. A Kaplan-Meier curve was performed to determine the survival after surgery. Also, a multivariate Cox regression was carried out to determine the variables that were independently associated with a lower survival rate. The statistical significance level used was p<0.05. Results: The sample was homogeneous according to clinical and demographic variables. The overall survival rate was 93% at the end of the study, with a mean follow up of 5.8 years. The older age (HR=1.15; p=0.001) and the history of perioperative low cardiac output syndrome (HR= 3.54; p=0.037) were the variables independently associated to lower survival in the follow-up. Conclusions: The patients' survival when concluded the follow-up was high. The older age and the perioperative low cardiac output syndrome were the variables independently associated to lower survival.

Partial characterization of ethanolic extract of Melipona beecheii propolis and in vitro evaluation of its antifungal activity

ABSTRACT The ethanolic extract of Melipona beecheii Bennett 1831, propolis from Yucatán Mexico was evaluated in vitro for the determination of its phenolic compound content, antioxidant capacity and antifungal activity. The results were compared against those of the ethanolic extract of Apis mellifera propolis. The total phenolic content, flavonoid content and flavanones-dihydroflavonols content were assessed by colorimetric methods. The antifungal activity was assessed in vitro against Candida albicans. For the ethanolic extract of M. beecheii propolis; total phenolic content, was 263.25 ± 8.78 µg/ml, total flavonoid content was 768 ± 204 µg/ml and flavanones-dihydroflavonols content was 335.42 ± 15.08 µg/ml. For antioxidant activity assessed as DPPH scavenging and iron reducing power ethanolic extract of M. beecheii propolis reported IC50 of 32.47 and 1.60 µg/ml of gallic acid equivalent respectively. Regarding antifungal activity against C. albicans, the minimal inhibitory concentration and minimal fungicidal concentration for ethanolic extract of M. beecheii propolis were 1.62 ± 0.33 and 2.50 ± 0.22 µg/ml of dry extract; For both minimal inhibitory concentration and minimal fungicidal concentration, ethanolic extract of M. beecheii propolis required 30% less concentration of dry extract than ethanol extract of A. mellifera propolis to exert the same antifungal actions against C. albicans. To the best of our knowledge, this is the first report about the flavonoid and flavanones-dihydroflavonols content of M. beecheii propolis. Due to the lack of information available about the stingless bee's honeycomb products, the study and conservation of endemic honeybees should remain as an active focus of research.

Pentacyclic triterpenes and other constituents in propolis extract from Melipona beecheii collected in Yucatan, México

ABSTRACT Thirteen pentacyclic triterpenes, methyl 3-oxours-12-en-23-oate, marsformosanone, taraxerone, β-amyrenone, α-amyrenone, lupenone, 24-methylencycloartan-3-one, moretenol acetate, β-amyrin acetate, germanicol acetate, 24-methylencycloartanyl acetate, β-amyrin, and α-amyrin were identified in a chloroform-methanol propolis extract from Melipona beecheii. Additionally, were identified in this propolis, hexadecanoic acid, methyl ester, octadecanoic acid, methyl ester and 1-triacontanol. The purification of the propolis extract was carried out using different chromatographic techniques, including vacuum liquid chromatography, gravity column chromatography and gel filtration chromatography Sephadex LH-20. The identification of the metabolites was performed using mass spectrometry.

Predictores de bajo gasto cardíaco perioperatorio en pacientes operados de cirugía cardíaca valvular / Predictors of low perioperative cardiac output in patients with heart valve surgery

RESUMEN Introducción: El síndrome de bajo gasto cardíaco (BGC) perioperatorio es una complicación frecuente en el postoperatorio de cirugía cardíaca la cual disminuye la supervivencia a corto plazo. Objetivo: Determinar las variables que pronostican de manera independiente la incidencia del BGC en el perioperatorio de cirugía cardíaca valvular en el Instituto de Cardiología y Cirugía Cardiovascular, durante el trienio 2012-2014. Método: Se realizó un estudio de cohorte donde se conformaron dos grupos: uno con BGC (46 pacientes) y otro sin él (110 pacientes). Se realizó una curva de Kaplan-Meier para determinar la supervivencia a los 30 días de la cirugía, se compararon los grupos con la prueba de rangos logarítmicos (log-rank). Se efectuó un análisis multivariable para determinar las variables que influyeron de manera independiente en la aparición del BGC. El nivel de significación estadístico empleado fue de p<0,05. Resultados: La muestra fue homogénea según características clínicas y demográficas. La incidencia y la mortalidad del BGC fueron del 29,5% y 28,3%, respectivamente. La disfunción renal preoperatoria (OR=5,13; p=0,005), el tiempo prolongado de circulación extracorpórea (OR=4,89; p=0,001) y la resistencia vascular pulmonar elevada (OR=7,52; p<0,001) fueron las variables que se asociaron de manera independiente a la aparición de bajo gasto. Conclusiones: El BGC reduce significativamente la supervivencia perioperatoria. La disfunción renal preoperatoria, el tiempo prolongado de circulación extracorpórea y la resistencia vascular pulmonar elevada constituyeron variables de peor pronóstico en estos pacientes, asociadas a una mayor probabilidad de sufrir esta complicación.

ABSTRACT Introduction: The perioperative low cardiac output syndrome (LCOS) is a frequent complication in the postoperative period of cardiac surgery which decreases short-term survival. Objective: To determine the variables that independently predict the incidence of LCOS in the perioperative period of heart valve surgery at the Instituto de Cardiología y Cirugía Cardiovascular, during the 2012-2014 triennium. Method: A cohort study was conducted where two groups were formed: one with LCOS (46 patients) and the other without it (110 patients). A Kaplan-Meier curve was performed to determine survival 30 days after surgery. The groups were compared with the log-rank test. A multivariate analysis was carried out to determine the variables that independently influenced the appearance of LCOS. The level of statistical significance used was p<0.05. Results: The sample was homogeneous according to clinical and demographic characteristics. The incidence and mortality of the LCOS were 29.5% and 28.3%, respectively. Preoperative renal dysfunction (OR=5.13, p=0.005), prolonged extracorporeal circulation time (OR=4.89, p=0.001) and elevated pulmonary vascular resistance (OR=7.52, p<0.001) were the variables independently associated with the appearance of low cardiac output. Conclusions: The LCOS significantly reduces perioperative survival. Preoperative renal dysfunction, prolonged extracorporeal circulation and elevated pulmonary vascular resistance were variables of worse prognosis in these patients, associated with a higher probability of suffering this complication.

[Prevalence of allergic diseases in children with secondary renal tubular acidosis attending a tertiary care pediatric center]. / Prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria que acudieron a un hospital pediátrico de tercer nivel.

BACKGROUND: It has been suggested a high prevalence of allergic disease in children with RTA. OBJECTIVE: To describe the prevalence of allergic diseases in children with secondary RTA (renal tubular acidosis) in the nephrology department of the National Institute of Pediatrics (NIP), México. METHODS: An observational, prospective, cross-sectional, descriptive study. Children with secondary RTA < 18 years who attended the outpatient nephrology service in the NIP for 24 months, were included. ISAAC questionnaire and the EAACI guidelines were applied. To prove a suspected allergy, skin tests, total and specific IgE, patch testing and food challenge were performed. Using SPSS 19, frequency of allergic diseases was described. RESULTS: 113 patients were included. Age 8 to 168 months. Male: 53.9 %. RTA types: Distal (64.6 %), proximal (26.5 %), mixed (1.8 %) and undetermined (7 %). Age of onset between 1 and 96 months. Serum bicarbonate 10.1 to 20 mEq/L. Allergic diseases were found in 24.8 %: allergic rhinitis (18.4 %), food allergy (9.7 %), atopic dermatitis (8 %), asthma (8 %) and allergic conjunctivitis (6.1 %). Total IgE was increased in 9 patients. Positive skin tests in 14.2 %. Positive chemiluminescence in 18 children; positive open food challenge in 11 children and patch tests in 4. CONCLUSION: Secondary RTA is common in children attending tertiary care hospitals. The prevalence of allergic disease in children with secondary ATR, is similar to that described in the general population.

Antecedentes: Se ha sugerido elevada prevalencia de enfermedades alérgicas en niños con acidosis tubular renal. Objetivos: Describir la prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria atendidos en el Servicio de Nefrología del Instituto Nacional de Pediatría, México. Métodos: Estudio observacional, prospectivo, transversal, descriptivo. Se incluyeron niños atendidos durante 24 meses. Se aplicó el cuestionario ISAAC y los criterios de la guía EAACI. Ante sospecha de alergia se realizaron pruebas cutáneas, IgE total y específica, pruebas del parche y reto alimentario. Resultados: Se incluyeron 113 pacientes con edades entre 8 y 168 meses; 53.9 % del sexo masculino. Tipos de acidosis tubular renal: distal (64.6 %), proximal (26.5 %), mixta (1.8 %) y no determinada (7 %). La edad de inicio osciló entre 1 y 96 meses. Se registró 10.1 a 20 mEq/L de bicarbonato sérico; 24.8 % mostró enfermedades alérgicas: 18.4 % rinitis alérgica, 9.7 % alergia alimentaria, 8 % dermatitis atópica, 8 % asma y 6.1 % conjuntivitis alérgica. Se observó IgE total elevada en 9 pacientes. En 14.2 % las pruebas cutáneas fueron positivas y la quimioluminiscencia en 18 niños; el reto abierto con alimentos fue positivo en 11 y las pruebas del parche en 4. Conclusiones: La prevalencia de enfermedades alérgicas en niños con acidosis tubular renal secundaria fue similar a la de la población general.

Encapsulation of vegetable oils as source of omega-3 fatty acids for enriched functional foods.

Polyunsaturated omega-3 fatty acids (PUFAs), a functional component present in vegetable oils, are generally recognized as being beneficial to health. Omega-3 PUFAs are rich in double bonds and unsaturated in nature; this attribute makes them highly susceptible to lipid oxidation and unfit for incorporation into long shelf life foods. The microencapsulation of oils in a polymeric matrix (mainly polysaccharides) offers the possibility of controlled release of the lipophilic functional ingredient and can be useful for the supplementation of foods with PUFAs. The present paper provides a literature review of different vegetable sources of omega-3 fatty acids, the functional effects of omega-3 fatty acids, different microencapsulation methods that can possibly be used for the encapsulation of oils, the properties of vegetable oil microcapsules, the effect of encapsulation on oxidation stability and fatty acid composition of vegetable oils, and the incorporation of long-chain omega-3 polyunsaturated fatty acids in foods.

Efficient transformation of Mycosphaerella fijiensis by underwater shock waves.

Black leaf streak disease, also known as black Sigatoka, causes dramatic losses in production of banana and plantains fruits. The disease is caused by the pathogenic fungus Mycosphaerella fijiensis (anamorph Pseudocercospora fijiensis; Mycosphaerellaceae). Genetic transformation of M. fijiensis would allow a better understanding of molecular basis of pathogenicity and design novel approaches to control the infection caused by this pathogen. However, transformation of this fungus has not been easy. We report here a protocol for genetic transformation of M. fijiensis employing underwater shock waves and intact conidia. The recombinant strains recovered showed genetic stability over >10 generations. The frequency of transformation obtained was between 75 and 150 times higher than the efficiency reported in the only article published on transformation of M. fijiensis using spheroplasts. This improvement allowed the use of a thousand times less cells than the amount employed before, avoiding the need for cumbersome successive batch cultures. Our protocol is simple, highly efficient, fast and reproducible and together with the available genomes of M. fijiensis and Musa acuminata, it offers new possibilities to study the diverse mechanisms of pathogenesis of the fungus.

Recombinant expression of four oxidoreductases in Phanerochaete chrysosporium improves degradation of phenolic and non-phenolic substrates.

Phanerochaete chrysosporium belongs to a group of lignin-degrading fungi that secretes various oxidoreductive enzymes, including lignin peroxidase (LiP) and manganese peroxidase (MnP). Previously, we demonstrated that the heterologous expression of a versatile peroxidase (VP) in P. chrysosporium recombinant strains is possible. However, the production of laccases (Lac) in this fungus has not been completely demonstrated and remains controversial. In order to investigate if the co-expression of Lac and VP in P. chrysosporium would improve the degradation of phenolic and non-phenolic substrates, we tested the constitutive co-expression of the lacIIIb gene from Trametes versicolor and the vpl2 gene from Pleurotus eryngii, and also the endogenous genes mnp1 and lipH8 by shock wave mediated transformation. The co-overexpression of peroxidases and laccases was improved up to five-fold as compared with wild type species. Transformant strains showed a broad spectrum in phenolic/non-phenolic biotransformation and a high percentage in synthetic dye decolorization in comparison with the parental strain. Our results show that the four enzymes can be constitutively expressed in a single transformant of P. chrysosporium in minimal medium. These data offer new possibilities for an easy and efficient co-expression of laccases and peroxidases in suitable basidiomycete species.

Electrophoresis characterisation of protein as a method to establish the entomological origin of stingless bee honeys.

Increasing production of stingless-bee honey and the prospect of broader marker for natural and organic products indicate the need to establish parameters to determinate the entomological origin and authenticity of honey. In this research, honeys of Apis mellifera, Melipona beecheii and Trigona spp. were collected in Yucatan, Mexico. Stingless-bee honeys contained more water and less total sugars and reducing sugars. SDS-PAGE patterns show distinctive bands for each kind of honey. The SDS-PAGE pattern of A. mellifera proteins honey showed three bands with molecular weights between 10.2 and 74.8kDa, there were five proteins bands in M. beecheii honey with molecular weights between 6.1 and 97.0kDa and nine for Trigona spp. proteins between 9.3 and 86.7kDa. Conventional physicochemical parameters along with electrophoresis profiles of stingless-bee honeys proteins could be an alternative for determination of entomological origin.

Antioxidant compounds, antioxidant activity and phenolic content in peel from three tropical fruits from Yucatan, Mexico.

The aim of this study was to determine the antioxidant compounds, antioxidant activity and content of individual phenolic compounds of freeze-dried peel from three tropical fruits grown in Yucatan, México: purple star apple (Chrysophyllum cainito L.), yellow cashew and red cashew (Anacardium occidentale). The freeze-dried peels were good source of antioxidant compounds. ABTS and DPPH values in the peel from each fruit were 3050.95-3322.31 µM Trolox/100g dry weight (DW) or 890.19-970.01 mg of vitamin C/100 g DW, and 1579.04-1680.90 µM Trolox/100 g DW or 340.18-362.18 mg of vitamin C/100 g DW, respectively. Six phenolic compounds were identified in the peel from the tropical fruits studied: ferulic, caffeic, sinapic, gallic, ellagic and myricetin. This study demonstrated that freeze-dried peels from purple star apple, yellow cashew and red cashew, could serve as potential sources of antioxidants for use in food and pharmaceutical industries.

Determination of some physicochemical characteristics, bioactive compounds and antioxidant activity of tropical fruits from Yucatan, Mexico.

The aim to the study was to determine the physicochemical composition, bioactive compounds and antioxidant activity of fruits from Yucatan, Mexico such as star apple, cashew, mombin, mamey sapote, white sapote, sugar apple, sapodilla, dragon fruit, nance, ilama, custard apple, mamoncillo and black sapote. The physicochemical characteristics were different between fruits and were good sources of bioactive compounds. The edible part with the highest values of antioxidant activity were mamoncillo, star apple, mombin, cashew, white sapote, ilama, custard apple, sugar apple, and nance. Total soluble phenols content showed a correlation with antioxidant activity by ABTS (R=0.52, P⩽0.05) and DPPH (R=0.43, P⩽0.05). A high correlation was obtained between the two assays (ABTS and DPPH) used to measure antioxidant activity in the tropical fruit species under study (R=0.82, P⩽0.05). The results show promising perspectives for the exploitation and use of tropical fruits studied with significant levels of nutrients and antioxidant activity.

A novel and highly efficient method for genetic transformation of fungi employing shock waves.

Genetic transformation of filamentous fungi is an essential tool in many areas such as biotechnology, medicine, phytopathology and genetics. However, available protocols to transform fungi are inefficient, laborious and have low reproducibility. We report the use of underwater shock waves as a novel method to transform filamentous fungi. An experimental piezoelectric shock wave generator was designed to expose fungal conidia to heterologous DNA. The device was successfully tested in Aspergillus niger, Fusarium oxysporum, Trichoderma reesei and Phanerochaete chrysosporium. The transformation frequency per number of conidia was between two and four orders of magnitude higher in comparison to previously published methods. For example, the frequency of transformation in A. niger was improved up to 5400-fold as compared with Agrobacterium protocols. Transformation was verified by expression of the green fluorescent protein, PCR and Southern blot. Our method offers new possibilities for fast, easy and efficient genetic manipulation of diverse fungal species.