Approaches to Enhancing the Viability of Lactic Acid Microorganisms

Abstract

Abstract—Approaches to stabilizing the cells of lactic acid organisms (LAO) investigated in the present work resulted in maintaining the viable cell titer at 10⁷–10⁸ cells/mL, the value recommended for the LAO titer in foodstuffs, for 12 months. Natural LAO associations selected for long-term preservation of LAO cell viability exhibited high efficiency. Lactic acid bacteria Lactobacillus plantarum and yeasts Candida parapsilosis were isolated from the association isolated from marketed curdled milk and selected for 6 months. The death rate of these LAO in binary culture (50% of each component) was several times lower than in monocultures. Adding other approaches for cell stabilization in a binary LAO culture (anoxic conditions and stabilizing antioxidant and biopolymer supplements) resulted in a 5- to 6-fold increase in the number of viable cells after 12-month storage. The algorithm for combined application of several approaches to prolongation of cell viability in the cultures of lactic acid microorganisms during long-term storage (up to 12 months) was not reported previously. It may be recommended for LAO cell stabilization both in fermented milk products and in leaven cultures. This is the first report of C. parapsilosis as the yeast component of a stable association with lactic acid bacteria.