Adaptation and development of culture-independent techniques for the indentification and enumeration of microorganisms in wine fermentations

Identifier:  TDX:469

Handle: https://hdl.handle.net/20.500.11797/TDX469

Authors:  Andorrà Solsona, Immaculada

Abstract:
The objective of this thesis was the adaptation and validation of different culture-independent techniques for detection and quantification of the microbiota present in wine fermentation. We tested the QPCR (PCR quantitative) for the quantification and monitoring of key species. The ecological diversity was analyzed by DGGE (denaturing gradient gel electrophoresis) and by cloning of a ribosomal fragment. However, we studied the application of in Situ Hybridization (FISH) and QPCR with specific dyes to differentiate between live and dead cells. These techniques were applied in industrial fermentations, being significant the detection of acetic acid bacteria and Non-Saccharomyces yeast in concentrations higher than those identified as culturable populations. We studied the interactions between Saccharomyces and Non-Saccharomyces yeast in the laboratory, observing their survival in these viable but non-culturable state. These culture-independent techniques indicate a population and microbial dynamics previously unnoticed.