Viability and resistance of lactobacilli isolated from cocoa fermentation to simulated gastrointestinal digestive steps in soy yogurt.

To study the potential probiotic characteristics such as decrease of pH, microbial viability, and tolerance to simulated digestive steps of fermented soy beverage ("soy yogurt") produced with lactobacilli isolated from cocoa fermentation (Lactobacillus fermentum TcUESC01 and Lactobacillus plantarum TcUESC02) during fermentation and refrigerated storage. The sensory acceptance of the yogurts was also tested. Samples of soy yogurt produced with L. fermentum TcUESC01 or L. plantarum TcUESC02 were collected during fermentation (0, 4, 8, and 12 h) and refrigerated storage (1, 9, 18, and 27 d), and submitted to pH and bacterial viability determinations. Tolerance to simulated digestion steps was done with refrigerated storage samples at 9 °C. Simulated digestion was performed in 3 successive steps: exposure to pepsin-HCl solution, bile shock, and simulated small intestinal juice. During storage, a decrease in pH and lactobacillus viability was observed. L. fermentum TcUESC01 showed to be more resistant than L. plantarum TcUESC02 to simulated gastrointestinal digestion. All soy yogurts showed acceptable hedonic scores (greater than 5 in a 9-point hedonic scale ranging from "like extremely" to "dislike extremely") in sensory evaluation for flavor, aroma, color, consistency, and overall impression. L. plantarum TcUESC02 and, especially, L. fermentum TcUESC01 showed potential probiotic characteristics when considering pH, cell viability, and tolerance to simulated digestive steps and did not affect the sensory characteristics when supplemented to soy yogurt during storage.

Application of denaturing gradient gel electrophoresis for detection of bacterial and yeast communities along a salinity gradient in the estuary of the Cachoeira River in Brazil.

An estuary is a transition zone between freshwater and marine ecosystems, resulting in dilution of seawater. Estuaries are also considered environments of intense biological activity related to the processes of nutrient cycling. The aim of this study was to evaluate the microbial community composition along a salinity gradient in the estuary of the Cachoeira River, located in southern Bahia, Brazil. The analysis of bacterial and yeast communities was performed by determining the denaturing gradient gel electrophoresis band richness. Formation of zones with similar profiles of bands was observed, and the increasing richness at the intermediate zone demonstrated a clear spatial distinction of communities depending on salinity. In addition, the dissolved oxygen content, temperature, pH, salinity, and dissolved inorganic nutrient contents (NH3(+), NO2(-), NO3(-), PO4(-)) were determined. Nutrients were distributed in similar patterns, with decreasing concentrations as the salinity increases.

Filamentous fungi vectored by ants (Hymenoptera: Formicidae) in a public hospital in North-Eastern Brazil.

BACKGROUND: The increase in opportunistic fungal infections has led to the search for putative sources of contamination in hospital environments. AIM: Ants in a public hospital in Itabuna, north-eastern Brazil were examined for carriage of filamentous fungi. METHODS: During a year-long survey, ants from different hospital areas were sampled. Preference was given to locations where it was possible to observe ants actively foraging. The fungi found on the ants' integument were cultured and identified. FINDINGS: A total of 106 ant workers belonging to 12 species in 11 genera were collected. A total of 47 fungal strains was isolated from 40% of the ants (N = 42). We found 16 fungal species in 13 genera associated with the ant workers. The prevalent fungal genera were Aspergillus, Purpureocillium and Fusarium. The ants Tapinoma melanocephalum, Paratrechina longicornis and Pheidole megacephala were associated with six fungal genera; and four genera of fungi were associated with Solenopsis saevissima workers. Fungal diversity was higher in the following hospital areas: nursery, hospital beds, breastmilk bank and paediatrics. CONCLUSION: Ants act as carriers of soil and airborne fungal species, and ant control in hospital areas is necessary to prevent the dissemination of such micro-organisms.