Genetic diversity of Saccharomyces cerevisiae strains during the 24 h fermentative cycle for the production of the artisanal Brazilian cachaça.

AIMS: Characterization of yeast populations and genetic polymorphism of Saccharomyces cerevisiae strains collected during the short fermentative cycles from the spontaneous fermentations during the artisanal cachaça production. METHODS AND RESULTS: The prevalent S. cerevisiae strains were analysed by PFG and RAPD-PCR using primers EI1 and M13. The molecular analysis have showed a high degree of genetic polymorphism among the strains within a 24 h fermentative cycle. CONCLUSION: The genetic diversity observed in the S. cerevisiae strains may be occurring due to the existence of a large number of individual genotypes within the species. The unique characteristics of the cachaça fermentation process probably allows for a faster detection of molecular polymorphisms of yeast strains than other types of fermentations. SIGNIFICANCE AND IMPACT OF THE STUDY: Spontaneous fermentations to produce cachaça, due to their characteristics, are an excellent model for the study of molecular diversity of S. cerevisiae strains during the production of fermented beverages.

Yeast communities and genetic polymorphism of Saccharomyces cerevisiae strains associated with artisanal fermentation in Brazil.

Yeast communities and genetic polymorphism of prevalent Saccharomyces cerevisiae strains isolated from the spontaneous fermentation of the sugarcane juice during the production of aguardente in three distilleries in the state of Minas Gerais, Brazil, were studied. S. cerevisiae was the prevalent species during the process of aguardente production, but Schizosaccharomyces pombe was predominant in old fermentations in one distillery. Transient yeast species were found in a variable number, probably due to the daily addition of sugarcane juice, and they were different for each of the three distilleries studied. PFGE and PCR analysis of the predominant strains of S. cerevisiae isolated from the fermented must showed a high degree of genetic polymorphism among the three distilleries. A high molecular variability of S. cerevisae strains was also observed among strains isolated from the same vat at different fermentation ages. Our results showed that there was a succession of geneticly different strains of S. cerevisae during the process of aguardente production.

Sequential clinical comparison between two commercially available rhinomanometers.

To assess nasal resistance in the treated as well as decongested states, two custom-built rhinomanometers (Rhino-Comp, manufactured by Cintec, Sweden, and Rhinomanometer 200, manufactured by Atmos, Germany) were sequentially employed in 53 non-selected consecutive patients referred for chronic or recurring nasal obstruction complaints, using the same active anterior rhinomanometric method. Final mean results from both equipments were submitted to paired statistical analysis. No correlation was found between the R150 results provided by the two rhinomanometers, albeit a 1.26 to 1.30 difference was encountered in the Rhinomanometer 200/Rhino-Comp ratio when the averaged mean values of all R150 results from both equipments were compared, suggesting that the discrepancy could be due to technical specificities intrinsic to each apparatus, with a tendency to produce systematic R150 differences. When the graphic aspect of the curves from both equipments were compared using the Broms system parameter V2 values, a remarkable correlation was seen between Rhino-Comp and Rhinomanometer 200 in expiratory (but not inspiratory) results, suggesting that the expiratory curves produced by the two equipments are graphically similar, at least until the Broms system radius 2 interception. Enough data was also found to support the possibility that the manufacturer's option to use a nose adaptor instead of adhesive tape for anterior nares occlusion with the Rhinomanometer 200 equipment could interfere with nasal vestibular function and thus artificially affect resistance measurements. Finally, patients' preference for either equipment examination procedures are discussed.

Glucantime resistant Leishmania promastigotes are sensitive to pentostam.

Growth inhibition in vitro tests were used to study the susceptibility to pentostam of different Leishmania strains involved in cutaneous and mucocutaneous leishmaniasis--one glucantime sensitive strain, three naturally glucantime resistant strains and one glucantime resistant line developed by in vitro drug exposure. Contrasting with the high degree of glucantime resistance, all strains were sensitive to pentostam. These differences suggest that there is some relationship between chemical structure and in vitro activity for these antimonial compounds. These data justify a clinical re-evaluation to compare therapeutic efficacy of glucantime and pentostam in the treatment of leishmaniasis.