PT  - JOURNAL ARTICLE
AU  - Paolo Spettoli
AU  - Alessandra Bottacin
AU  - Marco P. Nuti
AU  - Arturo Zamorani
TI  - Immobilization of <em>Leuconostoc Oenos</em> ml 34 in Calcium Alginate Gels and its Application to Wine Technology
AID  - 10.5344/ajev.1982.33.1.1
DP  - 1982 Jan 01
TA  - American Journal of Enology and Viticulture
PG  - 1--5
VI  - 33
IP  - 1
4099  - http://www.ajevonline.org/content/33/1/1.short
4100  - http://www.ajevonline.org/content/33/1/1.full
SO  - Am J Enol Vitic.1982 Jan 01; 33
AB  - Leuconostoc oenos ML 34 cells were immobilized in 1.67% calcium alginate gels to test their ability to convert L-malic acid into L-lactic acid in wine. Activity of the immobilized cells, assayed in standard buffers, was highest at pH 4.0 and 15% ethanol (v/v), and it stayed constant for 540 min. The sequential replacement of the spent incubation medium with fresh medium gave rise to an increase in activity during the first two days and to a decrease in activity thereafter. After 36 days, the activity was 60% of the maximum. About 45% to 60% of the L-malic acid was transformed into L-lactic acid by the immobilized cells in wine, and the decrease in titratable acidity was equivalent to 50% of the L-malic acid originally present, in accordance with the mechanism of malolactic fermentation in winemaking. After stirring the gels in wine several times, the activity of the immobilized cells gradually decreased until no activity was detectable. The living cells inside the gel were 2 x 108/mL, and only 0.1% leakage occurred during use.