University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Adrian Roßbacher
(2018):
Identifizierung und phänotypische Charakterisierung von Milchsäurebakterien aus Sauerteig.
Master / Diploma Thesis - Institut für Lebensmittelwissenschaften,
BOKU-Universität für Bodenkultur,
pp 108.
UB BOKU
obvsg
- Abstract:
- In this work, the fermentation microbiota of two rye sourdoughs, one wheat sourdough and two dry sourdoughs were investigated and a basic identification and characterization of the isolates was carried out. The special importance of the use of different isolation media was shown to be able to isolate the broadest possible spectrum of microorganisms. By partial sequencing of the 16S rDNA most of the isolates could be assigned to one species. For further characterization the isolates were cultured in All Purpose Tween (APT) broth and the phenotypical results were then compared with literature data. All isolates tested were grampositive and catalase- and oxidasenegative. The growth of isolates was examined at 4°C, 15°C and 45°C in APT broth. Furthermore, the growth behavior was recorded in different APT broth modifications or at different incubation temperatures: sodium chloride concentration (4% and 8% (w/v)); incubation temperature (30°C and 37°C); pH (pH 3.8, pH 4.0 and pH 9.0). The optical density was recorded continuously with the BioscreenC photometer and the results were displayed as growth diagrams. The obtained data confirmed the identity of most isolates determined by partial 16S rDNA sequencing and allowed the preliminary taxonomical assignment of previously unidentified isolates. Future work will require the extension of the polyphasic approach to uniquely identify the isolates at the species level and to describe the sourdough-relevant characteristics (e.g., carbohydrate utilization profiles, antimicrobial properties).
- Beurteilende(r): Domig Konrad