Ascomycetous yeast species recovered from grapes damaged by honeydew and sour rot.
OBJECTIVE
To identify ascomycetous yeasts recovered from sound and damaged grapes by the presence of honeydew or sour rot.


RESULTS
In sound grapes, the mean yeast counts ranged from 3.20 +/- 1.04 log CFU g(-1) to 5.87 +/- 0.64 log CFU g(-1). In honeydew grapes, the mean counts ranged from 3.88 +/- 0.80 log CFU g(-1) to 6.64 +/- 0.77 log CFU g(-1). In sour rot grapes counts varied between 6.34 +/- 1.03 and 7.68 +/- 0.38 logCFU g(-1). Hanseniaspora uvarum was the most frequent species from sound samples. In both types of damage, the most frequent species were Candida vanderwaltii, H. uvarum and Zygoascus hellenicus. The latter species was recovered in high frequency because of the utilization of the selective medium DBDM (Dekkera/Brettanomyces differential medium). The scarce isolation frequency of the wine spoilage species Zygosaccharomyces bailii (in sour rotten grapes) and Zygosaccharomyces bisporus (in honeydew affected grapes) could only be demonstrated by the use of the selective medium ZDM (Zygosaccharomyces differential medium).


CONCLUSIONS
The isolation of several species only from damaged grapes indicates that damage constituted the main factor determining yeast diversity. The utilization of selective media is required for eliciting the recovery of potentially wine spoilage species.


CONCLUSIONS
The impact of damaged grapes in the yeast ecology of grapes has been underestimated.
Barata
A
A
Laboratório de Microbiologia, Departamento de Botânica e Engenharia Biológica, Instituto Superior de Agronomia, Technical University of Lisbon, Lisboa, Portugal.
Seborro
F
F
Belloch
C
C
Malfeito-Ferreira
M
M
Loureiro
V
V
D002175:Candida / Q000302:isolation & purification; D017753:Ecosystem; D005516:Food Microbiology; D005800:Genes, Fungal; D007716:Kluyveromyces / Q000302:isolation & purification; D016533:Mycological Typing Techniques; D009181:Mycoses / Q000382:microbiology*; D010935:Plant Diseases / Q000382:microbiology*; D012150:Polymorphism, Restriction Fragment Length; D027843:Vitis / Q000382:microbiology*; D015003:Yeasts / Q000302:isolation & purification*; D020068:Zygosaccharomyces / Q000302:isolation & purification