Evaluation of a serum-free transport medium supplemented with cyanobacterial extract, for the optimal survival of Helicobacter pylori from biopsy samples and strains.

The purpose of this work was to evaluate the use of an alternative transport medium supplemented with a cyanobacterial extract (CE), free of animal derivatives, to preserve the viability of Helicobacter pylori strains during long-term transportation and allow its recovery from biopsy samples. The transport media evaluated were Mueller-Hinton broth 0.3% agar (MH) and 0.3% of CE (MH-CE). MH broth 5% fetal calf serum (FCS) was used as the reference medium (MH-FCS). Biopsy samples from 134 patients, H. pylori NCTC 11638 and six clinical isolates were studied. A higher recovery (p ≤ 0.001) at 4°C was obtained in MH-CE than in MH-FCS after 96 h of storage. Only MH-CE allowed recovery after 120 h. The H. pylori recovery at room temperature after 96 h was higher (p ≤ 0.005) in MH-CE than in MH-FCS. Similar survival rates were observed in biopsy samples conserved in MH-CE and MH-FCS at 4°C. The recovery after 48 h at room temperature in MH-CE was higher (p ≤ 0.05) than MH-FCS and was the only medium allowing recovery after 72 h. The MH-CE medium is a simple, inexpensive and animal derivatives-free transport medium that can be used to preserve H. pylori viability and its recovery from biopsy samples.

Effect of mineral nutrients on cell growth and self-flocculation of Tolypothrix tenuis for the production of a biofertilizer.

The influence of mineral nutrients on the growth and self-flocculation of Tolypothrix tenuis was studied. The identification of possible limiting nutrients in the culture medium was performed by the biomass elemental composition approach. A factorial experimental design was used in order to estimate the contribution of macronutrients and micronutrients, as well as their interactions. Iron was identified to be limiting in the culture medium. The micronutrients influenced mainly cellular growth without effects on self-flocculation. Conversely, the self-flocculation capacity of the biomass increased at higher concentrations of macronutrients. The optimization of mineral nutrition of T. tenuis allowed a 73% increase in the final biomass level and 3.5 times higher flocculation rates.

Enhancement of growth and toxin production of Clostridium argentinense by co-culture with Pseudomonas mendocina.

The growth and toxin production of Clostridium argentinense in co-culture with Pseudomonas mendocina was examined in a micro-fermenter without aeration characterizing the association in terms of several growth parameters. The biomass obtained in co-cultures was 4.4 times higher than that in C. argentinense monocultures with total consumption of the carbon source. The pH and Eh attained in co-cultures at later stages of cultivation were suitable for toxin production by C. argentinense. In comparison with C. argentinense monocultures the production of toxin was 17.5 times higher with a specific toxicity of 0.56 LD50 per g of co-culture biomass.

Biodegradación de efluente rico en lípidos por bacterias autóctonas / Biodegradation of lipidh-rich effluent by native bacterium

A partir de muestras del efluente de una fábrica de tratamiento biológico existente en una fábrica de mayonesa y margarinas se aislaron cepas de bacterias caracterizadas por poseer una alta actividad lipolítica. Con la cepa que presentó la mayor actividad se efectuaron estudios de tratamiento del efluente final de la fábrica. Su comportamiento se comparó con cepas de reconocida actividad lipolítica (Yarrowia lipolytica y Saccharomycopsis lipolytica). La cepa autóctona aislada demostró poseer una capacidad de disminución de la demanda química de oxígeno específica muy superior a las otras ensayadas

Biodegradación de efluente rico en lípidos por bacterias autóctonas / Biodegradation of lipidh-rich effluent by native bacterium

A partir de muestras del efluente de una fábrica de tratamiento biológico existente en una fábrica de mayonesa y margarinas se aislaron cepas de bacterias caracterizadas por poseer una alta actividad lipolítica. Con la cepa que presentó la mayor actividad se efectuaron estudios de tratamiento del efluente final de la fábrica. Su comportamiento se comparó con cepas de reconocida actividad lipolítica (Yarrowia lipolytica y Saccharomycopsis lipolytica). La cepa autóctona aislada demostró poseer una capacidad de disminución de la demanda química de oxígeno específica muy superior a las otras ensayadas (AU)

[Biodegradation of a lipid-rich effluent by native bacteria]. / Biodegradación de efluente rico en lípidos por bacterias autóctonas.

From samples of effluent derived from a biological treatment plant of a mayonnaise and margarine producing factory, several bacteria strains presenting high lipolytic activities were isolated. The strain having the highest activity was used for treating a typical final effluent and the results obtained were compared with those achieved with Yarrowia lipolytica and Saccharomycopsis lipolytica strains. The isolated strain showed the highest specific capacity for reducing chemical oxygen demand (COD).

Influencia de la velocidad de crecimiento sobre la formacion de toxinas en microorganismos del genero Clostridium. / Influence of growth velocity on the toxin production in microorganisms of the genus Clostridium

Se analizo la relacion entre velocidad de crecimiento y formacion de toxina en cultivos de Clostridium botulinum tipo A y Clostridium perfringens tipo D obtenidos con distintos medios y sistemas de cultivo Los resultados obtenidos indican una relacion inversa entre velocidad de crecimiento y actividad toxigenica especifica

[Use of molasses and whey in culture media for the development and production of a toxin from Clostridium perfringens type D]. / Empleo de melaza y suero de queso en medios de cultivo para el desarrollo y produccion de toxina de Clostridum perfringens tipo D.

This work was undertaken to study the use of molasses and cheese whey in culture media for growth and toxigenic activities of C. perfringens type D. Three media were used namely: 1) A modified Gordon medium 2) a molasses medium and 3) a whey medium which composition are shown in Table 1. The experiments were carried out in a 400 ml microfermentor by using 300 ml of media with automatic pH control (7,0 +/- 0,1) at 37 degrees C. Samples were taken for determination of microbial count and toxigenic activity. Fig. 1, 2, and 3 show the results obtained. The toxigenic activities obtained with the molasses and the Gordon media are similar, while it was not detected any activity in the cheese whey medium. It can be concluded that molasses could be a suitable and inexpensive basic component of culture media for toxin production by C. perfringens type D.

Empleo de melaza y suero de queso en medios de cultivo para el desarrollo y produccion de toxina de Clostridum perfringens tipo D. / Use of molasses and cheese whey in culture media for growth and production of toxins of Clostridium perfringens type D

Se ensayo el empleo de melaza y suero de queso en la formulacion de medios para el desarrollo y produccion de toxina de una cepa de Clostridium perfringens tipo D y se comparan los resultados con el medio de Gordon modificado mencionado en la bibliografia. Las experiencias realizadas demuestram que empleando medio de melaza se alcanzan rendimientos de toxina similares a los obtenidos con el medio de Gordon modificado, con lo cual se concluye que la melaza puede ser un componente basico economico para la produccion de toxina del microorganismo citado. Con respecto al suero de queso como componente de medios puede concluir-se que debe descartarse su empleo en procesos de tipo discontinuo como el empleado en el presente trabajo, para la produccion de toxina de Clostridium perfringens tipo D

Empleo de melaza y suero de queso en medios de cultivo para el desarrollo y produccion de toxina de Clostridum perfringens tipo D. / [Use of molasses and whey in culture media for the development and production of a toxin from Clostridium perfringens type D]

This work was undertaken to study the use of molasses and cheese whey in culture media for growth and toxigenic activities of C. perfringens type D. Three media were used namely: 1) A modified Gordon medium 2) a molasses medium and 3) a whey medium which composition are shown in Table 1. The experiments were carried out in a 400 ml microfermentor by using 300 ml of media with automatic pH control (7,0 +/- 0,1) at 37 degrees C. Samples were taken for determination of microbial count and toxigenic activity. Fig. 1, 2, and 3 show the results obtained. The toxigenic activities obtained with the molasses and the Gordon media are similar, while it was not detected any activity in the cheese whey medium. It can be concluded that molasses could be a suitable and inexpensive basic component of culture media for toxin production by C. perfringens type D.

Empleo de melaza y suero de queso en medios de cultivo para el desarrollo y produccion de toxina de Clostridum perfringens tipo D. / Use of molasses and cheese whey in culture media for growth and production of toxins of Clostridium perfringens type D

Se ensayo el empleo de melaza y suero de queso en la formulacion de medios para el desarrollo y produccion de toxina de una cepa de Clostridium perfringens tipo D y se comparan los resultados con el medio de Gordon modificado mencionado en la bibliografia. Las experiencias realizadas demuestram que empleando medio de melaza se alcanzan rendimientos de toxina similares a los obtenidos con el medio de Gordon modificado, con lo cual se concluye que la melaza puede ser un componente basico economico para la produccion de toxina del microorganismo citado. Con respecto al suero de queso como componente de medios puede concluir-se que debe descartarse su empleo en procesos de tipo discontinuo como el empleado en el presente trabajo, para la produccion de toxina de Clostridium perfringens tipo D

Emprego da clorhexidina na cirurgia de fistulas anais e de cisto pilonidal. Estudo comparativo a nitrofurazona. / Use of chlorhexidine on surgery of anal fistulas and pilonidal sinus. A comparative study with nitrofurazona

Os autores fizeram um estudo comparativo entre duas substancias, a clorhexidina-emulsao a nitrofurazona-pomada, utilizando-as localmente nas feridas anais por-fistulectomias e exerese de cisto pilonidal, tendo como objetivo principal a verificacao da tolerancia das mesmas. Tecem breves comentarios de revisao da literatura concernente ao assunto e concluem por este trabalho que o uso da clorhexidina foi superior ao da nitrofurazona por ter havido melhor tolerancia, isto e, ausencia de sensibilizacao e de queixas dos pacientes na quase totalidade dos casos