L-Malic Acid Catabolism by Polyacrylamide Gel Entrapped Leuconostoc Oenos

¹ Istituto di Microbiologia-lattiero-casearia, Facoltá. di Agraria dell'Universitá, 06100 Perugia, Italy.

Malolactic conversion was attempted with Leuconostoc oenos cells which were immobilized in polyacrilamide gel. The properties of immobilized cells were examined and compared with the properties of free cells. The optimum cell concentration in the gel was 13 percent w/v (wet wt). The optimum pH for activity was 5.25 for both entrapped and free cells. Optimum temperatures were between 40° and 50°C for entrapped cells and between 45° and 55°C for free cells. The malolactic conversion rate by immobilized cells reached 71 percent after 10 minutes in buffered solutions containing 2.25 or 4.5 g/L of L-malic acid at pH 5.6 and about 76 percent after one hour in must at pH 3.3.