Molecular Techniques for Enumeration of Wine Spoilage

In this project we sought to develop/identify/examine QPCR methods to see if they can differentiate metabolically active microbial populations in wine.

The objectives for this research and the experiments conducted to meet the objectives include the following:

  1. Compare novel QPCR techniques, cell staining and plating assays for enumeration of
    injured/stressed yeast (Hanseniaspora sp. and Brettanomyces sp) and bacterial (lactic
    acid bacterial and acetic acid bacterial) populations. The goal of this objective is to
    identify appropriate methods/conditions to better allow QPCR to read metabolically
    active cells.
  2. To use the novel QPCR methods to determine the scope of non-culturable
    Brettanomyces populations that exist in true winery samples and to examine the
    contribution of nonculturable populations for production of spoilage compounds. For this
    objective we will compare the optimized QPCR method for Brettanomyces (Objective 1)
    with routine plating results as well as 4EP measurements obtained from a large number of
    samples (> 300) at four different wineries.

Unfortunately this project has been delayed due to personnel issues; two key research members for this work have left UC Davis to take positions elsewhere. These departures resulted in delayed progress on this project, so consequently a request for a no-cost extension has been made and approved in order to complete the study. New researchers are in place and work is underway.