Utilisation de l'épifluorescence pour la détection des micro-organismes dans le vin

Froudiere, Isabelle; Larue, F.; Lonvaud-Funel, Aline

doi:10.20870/oeno-one.1990.24.1.1224

Cited by 4 publications

(5 citation statements)

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“…One of the methods currently used to follow the survival of those microorganisms is the direct epifluorescence method (direct epifluorescence filter technique, DEFT). This technique was first described by Hobbie et al (1977) and is already used in wine to count micro-organisms before bottling (Froudiere et al 1990).…”

Section: Introductionmentioning

confidence: 99%

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Evidence for viable but nonculturable yeasts in botrytis-affected wine

Divol¹,

Lonvaud‐Funel²

2005

Journal of Applied Microbiology

124

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Aims: In Botrytis-affected wine, high concentrations of SO 2 are added to stop the alcoholic fermentation and to stabilize the wine. During maturing in barrels or bottle-ageing, an unwanted refermentation can sometimes occur. However, results of the usual plate count of wine samples at the beginning of maturing suggest wine microbial stability. The aim of this study was to investigate the mode of yeasts survival after the addition of SO 2 and to identify surviving yeasts. Methods and Results: Using direct epifluorescence technique, we observed the behaviour of cells after SO 2 addition and compared the cell number determined by this method with the result of plate counts. The persistent yeast species were identified using two methods: polymerase chain reaction (PCR)-restriction fragment length polymorphism and PCR-denaturing gradient gel electrophoresis. They were identified as Saccharomyces cerevisiae and Candida stellata, and after few months of maturing, other spoiling yeasts appeared, like Rhodotorula mucilaginosa or Zygosaccharomyces bailii. Conclusions: All characteristics of the cells lead to the conclusion that yeast persisted in wine in a viable but nonculturable-like state (VBNC). Suppression of the effect of free-SO 2 did not lead to the resuscitation of the cells; however, another method proved the capacity of the cells to exit from the VBNC-like state. Significance and Impact of the Study: This study permits the characterization of the presence of VBNC-like yeasts in wine. The ÔrefermentationÕ phenomenon is probably due to the exit of the VBNC state.

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Section: Introductionmentioning

confidence: 99%

“…This technique was first described by Hobbie et al. (1977) and is already used in wine to count micro‐organisms before bottling (Froudiere et al. 1990).…”

Section: Introductionmentioning

confidence: 99%

Evidence for viable but nonculturable yeasts in botrytis-affected wine

Divol¹,

Lonvaud‐Funel²

2005

Journal of Applied Microbiology

124

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“…Bioluminescence has been evaluated as a rapid technique, but so far its performance is not adequate in most cases, since the threshold level is too high and it cannot distinguish yeasts from bacteria ( Lonvaud‐Funel & Joyeux 1982). The direct epifluorescence technique (DEFT) is more applicable to routine wine control, especially since fluorescent dyes, other than the toxic acridine orange which was first used, are now available ( Froudière et al . 1990 ; Diaper & Edwards 1994).…”

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confidence: 99%

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

Millet

Lonvaud-Funel

2000

Lett Appl Microbiol

261

146

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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.

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“…The direct epiXuorescent Wlter technique (DEFT) generally involves staining of the microorganisms with a Xuorochrome dye, collection on a nonXuorescing membrane Wlter, and examination of the membrane using a Xuorescent microscopy. DEFT has been used in milk [68,75], yoghurt [76], meat and poultry [30,78,84], and wine [27,35]. Although it is a relatively rapid and sensitive method, the dyes used react indiscriminately with organic material and interference from preservatives such as sorbic acid has been reported.…”

Section: Viability and Cell Numbermentioning

confidence: 99%

Flow cytometry applications in the food industry

Comas-Riu

Rius

2009

J Ind Microbiol Biotechnol

102

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Flow cytometry has become a valuable tool in food microbiology. By analysing large numbers of cells individually using light-scattering and fluorescence measurements, this technique reveals both cellular characteristics and the levels of cellular components. Flow cytometry has been developed to rapidly enumerate microorganisms; to distinguish between viable, metabolically active and dead cells, which is of great importance in food development and food spoilage; and to detect specific pathogenic microorganisms by conjugating antibodies with fluorochromes, which is of great use in the food industry. In addition, high-speed multiparametric data acquisition, analysis and cell sorting, which allow other characteristics of individual cells to be studied, have increased the interest of food microbiologists in this technique. This mini-review gives an overview of the principles of flow cytometry and examples of the application of this technique in the food industry.

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Utilisation de l'épifluorescence pour la détection des micro-organismes dans le vin

Cited by 4 publications

References 0 publications

Evidence for viable but nonculturable yeasts in botrytis-affected wine

Evidence for viable but nonculturable yeasts in botrytis-affected wine

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

Flow cytometry applications in the food industry

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