The viable but non-culturable state of wine micro-organisms during storage

Abstract

V . M IL L ET AN D A. LO N VA UD -FU NE L . 2000. Colony counting and DEFT did not give the same results when wine micro-organisms were enumerated. Both methods were used to monitor the population of acetic acid bacteria (AAB) and lactic acid bacteria (LAB) during wine storage. Results suggest that part of the populations had reached a viable but non-culturable (VBNC) state. These cells were unable to produce colonies but could hydrolyse fluorescent esters and could be counted by DEFT. For AAB, O 2 deprivation quickly induced this state. Recovery from this state was very rapid as soon as O 2 was available. The response was not so clear for LAB during wine storage. However, a similar state was induced by sulfiting. Moreover, filtration of wine stored in barrels and contaminated by Brettanomyces, AAB and LAB demonstrated that cell size was not homogeneous. Cells which remained in wine after several weeks could pass through a 0·45-mm membrane. However, when they re-entered a growing phase, they were again retained by membrane filtration. During and after the decline phase, wine micro-organisms might survive as smaller cells in a VBNC state.

Acetic Acid Bacteria: Physiology and Carbon Sources Oxidation

“…Low recovery of strains due to the fraction of population that could reach a viable but non-culturable (VBNC) state has been stated. For instance in wine it was shown that VBNC status of spoiling AAB is induced by O 2 deprivation [32]. Whereas in vinegars some studies developed by no culture approaches, such as PCR/DGGE, revealed higher species diversity respect to that detected by culturing methods [3,33,34].…”

Diversity in Spoilage Yeast Dekkera/Brettanomyces bruxellensis Isolated from French Red Wine. Assessment During Fermentation of Synthetic Wine Medium

“…To test the strains in an enology context, the synthetic medium was close to a wine at the final phase of alcoholic fermentation (but without any polyphenols). Total cell numeration was chosen to avoid under-evaluating the population in regard to cells in a viable but non-cultivable state (viable and active cells that are not able to grow on classical solid medium), since this is often the case in long term cultures and under stressful conditions such as in alcoholcontaining medium 7,25 . Moreover, high metabolic activity was noted until the end of the experiments.…”

Profiling the Yeast Communities of Wine Fermentations Using Terminal Restriction Fragment Length Polymorphism Analysis

“…Traditionally, culture-based enrichment methods are used for detection and identification of yeasts in wine, but these methods can be time-consuming and can misrepresent the community present by biasing for the growth of less fastidious organisms (Heard and Fleet 1986), and the occurrence of viable-but-not-culturable (VBNC) cells in the low-pH, highethanol environment of wine can limit the sensitivity of these methods (Millet and Lonvaud-Funel 2000). To surmount these issues, culture-independent methods for comprehensively profiling wine microbiota have received more attention, with denaturing gradient gel electrophoresis (DGGE) the most popular (Cocolin et al 2000, Mills et al 2002.…”