AGFD 107 |
| The use of probiotics as dietary adjuncts or as a probiotic is a subject of intense and growing interest. Several reports have indicated that probiotics have the ability to provide several health benefits. However, in order for these bacteria to manifest beneficial effects, they need to achieve an essential mass through aggregation. Consequently, the ability of probiotics to aggregate is a desirable property sought for use in commercial food preparations. The objective of this research was to determine the effect of calcium on autoaggregation behavior of Lactobacillus reuteri. Six strains of Lactobacillus reuteri were cultured in MRS broth in anaerobic jars at 37ºC for 18 hours. Autoaggregation ability was measured as autoaggregation percentage. In this procedure, overnight culture was shaken at different times (30, 60, 90, 120, 150 min). After shaking, 2 ml of the upper suspension of the culture was transferred to anther tube and the optical density (O.D.610 nm) was measured. Three types of autoaggregation behavior characterized the strains: (1) autoaggregation sensitive (S) for strains that formed a precipitate resulting in a clear solution, (2) autoaggregation resistant (R) for strains that produced consistent turbidity, and (3) autoaggregation moderate (M) for strains that showed slight turbidity. Results showed that calcium ions induced the autoaggregation behavior. The presence of calcium in TPY induce autoaggregation within 30 minutes (>90% autoaggrgation). The SDS gel shows the presence of additional protein band in the presence of calcium. Higher incubation temperature (42° C compared to 34 °C) increased the ability of strains to autoaggregate. Our data indicated that calcium ions and incubation temperture influence autoaggregation behavior of Lactobacillus reuteri. |
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General Posters
1:00 PM-3:00 PM, Monday, 11 September 2006 Moscone Center -- Hall D, Poster
Division of Agricultural & Food Chemistry |