Optimization of a rapid method for studying the cellular location of beta-glucosidase activity in wine yeasts.
OBJECTIVE
To improve a method for determining beta-glucosidase activity and to apply it in yeasts isolated from wine ecosystems from "La Mancha" region and to know its cellular location.


RESULTS
A total of 82 wine yeasts were identified (PCR/RFLP) and evaluated for their beta-glucosidase activity. First, they were qualitatively evaluated by growth on YNB cellobiose, the activity was quantified using different culture media, under aerobic and anaerobic conditions and cells after 24-72 h of growth. To study the location activity, five fractions were obtained (supernatant, whole cell, cell wall, cytosol and cell membrane). The enzymatic assays were optimized, being: growth in YP cellobiose for 72 h in aeration conditions and, after cell removing, enzyme analysis with 128 g l(-1) of cellobiose as substrate, for 30 min at 30 degrees C. The genus that displayed the greatest activity were Pichia, Hanseniaspora and Rhodotorula, and the activity was intracellular.


CONCLUSIONS
The study showed that beta-glucosidase activity was induced by the carbon source and was aerobic dependent. The non-Saccharomyces species displayed the greatest activity, which was intracellular and strain-dependent.


CONCLUSIONS
This study developed a reliable method for screening beta-glucosidase activity in yeasts isolated from wine ecosystems. This activity is very important in the release of monoterpenols from glycoside precursors for the enhancement of wine aromas.
Arévalo Villena
M
M
Tecnología de Alimentos, Universidad de Castilla La Mancha, Ciudad Real, Spain.
Ubeda Iranzo
J F
JF
Cordero Otero
R R
RR
Briones Pérez
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AI
D002462:Cell Membrane / Q000201:enzymology; D002473:Cell Wall / Q000201:enzymology; D002475:Cellobiose / Q000378:metabolism; D003470:Culture Media; D003600:Cytosol / Q000201:enzymology; D005516:Food Microbiology; D010100:Oxygen / Q000378:metabolism; D016133:Polymerase Chain Reaction / Q000379:methods; D012150:Polymorphism, Restriction Fragment Length; D014920:Wine / Q000382:microbiology*; D015003:Yeasts / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D001617:beta-Glucosidase / Q000378:metabolism*
D003470:Culture Media; D002475:Cellobiose; D001617:beta-Glucosidase; D010100:Oxygen