Inhibition of mycotoxin-producing Aspergillus nomius vsc 23 by lactic acid bacteria and Saccharomyces cerevisiae

The effect of different fermenting microorganisms on growth of a mycotoxin- producing Aspergillus nomius was assayed. Two lactic acid bacteria, Lactobacillus fermentum and Lactobacillus rhamnosus, and Saccharomyces cerevisiae, all of which are widely used in fermentation and preservation of food, were assayed on their fungus inhibitory properties. Assays were carried out by simultaneous inoculation of one of the possible inhibiting microorganisms and the fungus or subsequent inoculation of one of the microorganisms followed by the fungus. All three microorganisms assayed showed growth inhibition of the mycotoxin-producing Aspergillus strain. L. rhamnosus O236, isolated from sheep milk and selected for its technological properties, showed highest fungal inhibition of the microorganisms assayed. The use of antifungal LAB with excellent technological properties rather than chemical preservatives would enable the food industry to produce organic food without addition of chemical substances.

Physiological variability arising from in vitro propagation of Nothofagus obliqua

As with cuttings, the microcuttings produced from in vitro generated shoots could be affected by topophysis. Very little research has been done about such in vitro effect. This paper reports the influence of the topophysis on the regeneration response (shoot multiplication, microcutting rooting and plantlet acclimation) of explants on the in vitro culture of juvenile N. obliqua trees. The results showed that the main responsible of the physiological variability arising from all the in vitro propagation stages is topophysis. This influence was found in the first culture and can be extended to the next subculture (multiplication stage). Growth of the obtained plants was also affected (rooting of microcuttings and plantlet acclimation). The multiplication rate was lower in apical portion (1:3.66) than basal portion (1:5.8) while rooting was 48.6 and 27.0 respectively. By the way, length of acclimated explants was 52.4 mm in the apical rooted explants and 28.7 mm in the basal ones at the 30th day. In order to reduce such variability, it is necessary to take into account the initial position of the explants during the establishment and multiplication stages of micropropagation of forest trees

Alteraciones histológicas relacionadas al Helicobacter pylori en niños / Helicobacter pylori associated with histological changes in children

El helicobacter pylori(HP) es descripto como causante de inflamación crónica primaria de la mucosa gástrica,tanto en adultos como en niños. Estudios de la histología de la mucosa gástrica relacionados con HP en el niño, incluyen en general adolescentes y adultos jóvenes mostrando una casuística poco numerosa. El objetivo fue evaluar alteraciones histólogicas de la mucosa gástrica infectada por HP, en una población exclusivamente pediátrica con molestias abdominales