Microencapsulation of essential thyme oil by spray drying and its antimicrobial evaluation against Vibrio alginolyticus and Vibrio parahaemolyticus / Microencapsulação do óleo essencial de tomilho e avaliação de sua atividade antibacteriana sobre V. alginolyticus e V. parhaemolyticus

Abstract The aims of this research were first, to evaluate the antibacterial potential of commercial thyme essential oil against V. alginolyticus and V. parahaemolyticys and second, using the spray drying technique to produce microcapsules. chemical compounds of thyme oil and microcapsules were identified and quantified being thymol the chemical component present at the highest concentration. Oil-in-water (O/W) emulsions were prepared and the microcapsules were obtained with a spray dryer using maltodextrin as wall material (ratio 1:4). Thyme oil and the microcapsules exhibited antimicrobial activity against V. parahaemolyticus and V. alginolyticus. The spray drying process did not affect the antimicrobial activity of thyme essentialoil.

Resumo Os objetivos desta pesquisa foram avaliar o potencial antibacteriano do óleoessencial de tomilho sobre V. alginolyticus e V. parahaemolyticys e produzir microcápsulas através do processo de secagem por aspersão (spray dryer). Os compostos químicos do óleo essencial de tomilho e das microcápsulas foram identificados e quantificadaos. Foi preparada uma emulsão de óleo em água (O/A) e em seguida foram produzidas microcápsulas em um spray dryer utilizando-se óleo essencial de tomilho e maltodextrina como material de parede na proporção de 1:4 respectivamente. Entre os vários compostos identificados, o timol apresentou maior concentração. O óleo essencial de tomilho e as microcápsulas exibiram atividade antibacteriana sobre V. parahaemolyticus e V. alginolyticus. O processo de secagem por aspersão não afetou a atividade antibacteriana do óleo essencial de tomilho.

Microencapsulation of essential thyme oil by spray drying and its antimicrobial evaluation against Vibrio alginolyticus and Vibrio parahaemolyticus.

The aims of this research were first, to evaluate the antibacterial potential of commercial thyme essential oil against V. alginolyticus and V. parahaemolyticys and second, using the spray drying technique to produce microcapsules. chemical compounds of thyme oil and microcapsules were identified and quantified being thymol the chemical component present at the highest concentration. Oil-in-water (O/W) emulsions were prepared and the microcapsules were obtained with a spray dryer using maltodextrin as wall material (ratio 1:4). Thyme oil and the microcapsules exhibited antimicrobial activity against V. parahaemolyticus and V. alginolyticus. The spray drying process did not affect the antimicrobial activity of thyme essentialoil.

Microencapsulation of essential thyme oil by spray drying and its antimicrobial evaluation against Vibrio alginolyticus and Vibrio parahaemolyticus

Abstract The aims of this research were first, to evaluate the antibacterial potential of commercial thyme essential oil against V. alginolyticus and V. parahaemolyticys and second, using the spray drying technique to produce microcapsules. chemical compounds of thyme oil and microcapsules were identified and quantified being thymol the chemical component present at the highest concentration. Oil-in-water (O/W) emulsions were prepared and the microcapsules were obtained with a spray dryer using maltodextrin as wall material (ratio 1:4). Thyme oil and the microcapsules exhibited antimicrobial activity against V. parahaemolyticus and V. alginolyticus. The spray drying process did not affect the antimicrobial activity of thyme essentialoil.

Resumo Os objetivos desta pesquisa foram avaliar o potencial antibacteriano do óleoessencial de tomilho sobre V. alginolyticus e V. parahaemolyticys e produzir microcápsulas através do processo de secagem por aspersão (spray dryer). Os compostos químicos do óleo essencial de tomilho e das microcápsulas foram identificados e quantificadaos. Foi preparada uma emulsão de óleo em água (O/A) e em seguida foram produzidas microcápsulas em um spray dryer utilizando-se óleo essencial de tomilho e maltodextrina como material de parede na proporção de 1:4 respectivamente. Entre os vários compostos identificados, o timol apresentou maior concentração. O óleo essencial de tomilho e as microcápsulas exibiram atividade antibacteriana sobre V. parahaemolyticus e V. alginolyticus. O processo de secagem por aspersão não afetou a atividade antibacteriana do óleo essencial de tomilho.

Characterisation of RO fouling in an integrated MBR/RO system for wastewater reuse.

Membrane filtration has gradually gained acceptance as the preferred pre-treatment for reverse osmosis (RO). In this paper, an integrated membrane bioreactor (MBR)/RO system for wastewater reuse treating real sewage water has been evaluated and the RO fouling has been characterised. The MBR achieved low values of organic matter, total nitrogen, PO(4)(3-), total organic carbon, turbidity and conductivity. Filtration with two different RO commercial membranes was performed after the MBR pre-treatment and the same average fouling rate (0.08 bar day(-1)) was noted. These results gained from the characterisation of the high quality MBR/RO permeate show its potential for water reuse. Inorganic precipitation appears to be the predominant form of fouling in the RO membranes. Calcium phosphate and alumino-silicates were identified by a scanning electron microscope combined with an energy dispersive X-ray and polysaccharides, amide and aliphatic structures were detected with attenuated total reflection infrared microspectroscopy.

New insights in mechanisms of bacterial inactivation by carvacrol.

AIMS: To study the mechanism of bacterial inactivation by carvacrol and the influence of genetic and environmental factors in its antimicrobial activity. METHODS AND RESULTS: In general, bacterial inactivation by carvacrol was higher in the Gram-positive Listeria monocytogenes than in the Gram-negative Escherichia coli and at acidic pH. At pH 4.0, 25 µl l(-1) of carvacrol for 5 h inactivated 1 and more than 5 log(10) cycles of E. coli and L. monocytogenes populations, respectively. Genetic and environmental factors also influenced cell resistance to carvacrol: rpoS and sigB deletion decreased carvacrol resistance in E. coli and L. monocytogenes, respectively; a heat shock induced a phenomenon of cross-protection to carvacrol treatments. Repair of sublethal injuries in cell envelopes suggested that carvacrol targets lipid fractions and proteins of these structures. This result was corroborated by attenuated total reflectance infrared microspectroscopy analysis. CONCLUSIONS: This study shows critical genetic and environmental factors, such as rpoS or sigB and heat shocks, and reveals new microbial structures involved in the mechanism of bacterial inactivation by carvacrol. SIGNIFICANCE AND IMPACT OF THE STUDY: A better understanding of the mechanisms of microbial inactivation is of great relevance to design more appropriate carvacrol treatments with high antimicrobial effects.

Inactivation of Bacillus amyloliquefaciens spores by a combination of sucrose laurate and pressure-assisted thermal processing.

The aim of this research was to study the effect of sucrose laurate ester (SL) on enhancing pressure-assisted thermal processing (PATP) inactivation of Bacillus amyloliquefaciens Fad 82 spores. B. amyloliquefaciens spores (∼108 CFU/ml) were suspended in deionized water, solutions of 0.1, 0.5, and 1.0% SL, and mashed carrots without or with 1% SL. Samples were treated at 700 MPa and 105°C for 0 (come-up time), 1, 2, and 5 min and analyzed by pour-plating and most-probable-number techniques. Heat shock (80°C, 10 min) was applied to untreated and treated samples to study the germination rates. Results were also compared against samples treated by high pressure processing (700 MPa, 35°C) and thermal processing (105°C, 0.1 MPa). Among the combinations tested, SL at concentrations of 1.0% showed the best synergistic effect against spores of B. amyloliquefaciens when combined with PATP treatments. In the case of high pressure and thermal processing treatments, SL did not enhance spore inactivation at the conditions tested. These results suggest that SL is a promising antimicrobial compound that can help reduce the severity of PATP treatments.

Novel molecular profiles of endometrial cancer-new light through old windows.

Endometrial carcinoma (EC) is the most common gynecological malignancy in the western world. A widely accepted dualistic model, which has been established on a morphological basis, differentiates EC into two broad categories: Type I oestrogen-dependent adenocarcinoma with an endometrioid morphology and Type II non-oestrogen-dependent EC with a serous papillary or clear cell morphology. Molecular genetic evidence indicates that endometrial carcinoma, as described in other malignancies, likely develops as the result of a stepwise accumulation of alterations in cellular regulatory pathways, such as oncogene activation and tumor suppressor gene inactivation, which lead to dysfunctional cell growth. These molecular alterations appear to be specific in Type I and Type II cancers. In type I endometrioid endometrial cancer, PTEN gene silencing in conjunction with defects in DNA mismatch repair genes, as evidenced by the microsatellite instability phenotype, or mutations in the K-ras and/or beta-catenin genes, are recognized major alterations, which define the progression of the normal endometrium to hyperplasia, to endometrial intraepithelial neoplasia, and then on to carcinoma. In contrast, Type II cancers show mutations of TP53 and Her-2/neu and seem to arise from a background of atrophic endometrium. Nevertheless, despite the great effort made to establish a molecularly-based histological classification, the following issues must still be clarified: what triggers the tumor cells to invade the myometrium and what causes vascular or lymphatic dissemination, finally culminating in metastasis? RUNX1, a transcription factor, was recently identified as one of the most highly over-expressed genes in a microarray study of invasive endometrial carcinoma. Another candidate gene, which may be associated with an initial switch to myometrial infiltration, is the transcription factor ETV5/ERM. These studies, as well as those conducted for other genes possibly involved in the mitotic checkpoint as a major mechanism of carcinogenesis in non-endometrioid endometrial cancer, could help in understanding the differences in the biology and the clinical outcome among histological types.

Response of two Salmonella enterica strains inoculated in model cheese treated with high hydrostatic pressure.

The aim of this work was to determine the response to high hydrostatic pressure and the ability for survival, recovery, and growth of 2 strains of Salmonella enterica (Salmonella enteritidis and Salmonella typhimurium) inoculated in a washed-curd model cheese produced with and without starter culture. Inoculated samples were treated at 300 and 400 MPa for 10 min at room temperature and analyzed after treatment and after 1, 7, and 15 d of storage at 12 degrees C to study the behavior of the Salmonella population. Cheese samples produced with starter culture and treated at 300 and 400 MPa showed maximum lethality; no significant differences in the baroresistant behavior of both strains were detected. Nevertheless, when starter culture was not present, the maximum lethality was only observed in cheese samples treated at 400 MPa, in the case of S. enteritidis. Ability to repair and grow was not observed in model cheese produced with starter culture and cell counts of treated samples decreased after 15 d of storage at 12 degrees C. In cheese produced without starter culture, Salmonella cells showed the ability to repair and grow during the storage period, reaching counts over 3 log(10) (cfu/mL) in both applied treatments and serotypes. These results suggest that high hydrostatic pressure treatments are effective to reduce Salmonella population in this type of cheese, but the presence of the starter culture affects the ability of this microorganism to repair and grow during the storage period.

Elevada incidencia de premutaciones en el gen fmr1 en mujeres españolas con fallo ovárico prematuro / High incidence of premutations in the FMR1 gene in Spanish women with premature ovarian failure

Objetivo: Valorar la necesidad de incluir el estudio del gen FMR1 y/o FMR2, dos genes responsables de retraso mental, en los protocolos de estudio de las mujeres que presentan fallo ovárico prematuro (FOP) de causa idiopática.Sujetos y métodos: Se ha estudiado la zona repetitiva CGG de los genes FMR1 y FMR2 a 45 mujeres que consultaban al Servicio de Ginecología o Genética del Hospital Clínic de Barcelona por presentar menopausia precoz.Resultados: En 2 mujeres (4,4 por ciento) se ha detectado una expansión del triplete CGG en el gen FMR1 correspondiente a una premutación. No se ha detectado ninguna variación del rango de la normalidad en el triplete CGG en el gen FMR2. La incidencia de mujeres portadoras de premutación en el gen FMR1 entre la población de mujeres que presentan menopausia precoz es 11 veces mayor que la de la población general (1/246).Conclusiones: Un tercio de los casos de FOP son familiares, lo cual indica la necesidad de los estudios genéticos. Dada la elevada incidencia de portadoras de premutación en el gen FMR1 en la población de mujeres con FOP, el riesgo que esto comporta para su descendencia (un 50 por ciento de riesgo de tener un hijo con retraso mental) y la facilidad del estudio molecular, se recomienda incluir el estudio del gen FMR1 en los protocolos genéticos de FOP. (AU)

Frequency of the arylsulphatase A pseudodeficiency allele in the Spanish population.

Pseudodeficiency in arylsulphatase A (ASA) is a relatively frequent condition in healthy individuals. It produces a reduction in enzyme activity similar to that found in metachromatic leukodystrophy (MLD). Unambiguous discrimination between the two conditions cannot be achieved through conventional enzyme activity assays. A PCR method has been developed which detects the pseudodeficiency (pd) allele using a single pair of primers encompassing the mutation site and hair follicles as the source of DNA. The frequency of this allele in the Spanish population has been evaluated and correlations between different genotypes and ASA activity levels have been established. Ten out of 55 individuals were heterozygous for the ASA pd allele, while two were homozygous. The allele frequency was thus 12.7%.