Production of Conjugated Linoleic and Conjugated α-Linolenic Acid in a Reconstituted Skim Milk-Based Medium by Bifidobacterial Strains Isolated from Human Breast Milk

Eight bifidobacterial strains isolated from human breast milk have been tested for their abilities to convert linoleic acid (LA) and alpha-linolenic acid (LNA) to conjugated linoleic acid (CLA) and conjugated alpha-linolenic acid (CLNA), respectively. These bioactive lipids display important properties that may contribute to the maintenance and improvement human health. Three selected Bifidobacterium breve strains produced CLA from LA and CLNA from LNA in MRS (160-170 and 210-230 mu g mL(-1), resp.) and, also, in reconstituted skim milk (75-95 and 210-244 mu g mL(-1), resp.). These bifidobacterial strains were also able to simultaneously produce both CLA (90-105 mu g mL(-1)) and CLNA(290-320 mu g mL(-1)) in reconstituted skim milk. Globally, our findings suggest that these bifidobacterial strains are potential candidates for the design of new fermented dairy products naturally containing very high concentrations of these bioactive lipids. To our knowledge, this is the first study describing CLNA production and coproduction of CLA and CLNA by Bifidobacterium breve strains isolated from human milk in reconstituted skim milk.