Servizio Comunitario di Informazione in materia di Ricerca e Sviluppo - CORDIS

Identification of food grade bacteria with CLA biosynthetic capability

Certain bacterial species associated with food fermentations, including propionibacteria, lactobacilli, lactococci and streptococci have the ability to produce CLA from linoleic acid. Furthermore, bacterial inhabitants of the human intestine possess the ability to generate c9, t11 CLA from free linoleic acid (intestinal microflora of rats and bifidobacteria (Coakley et al.,2003; Rosberg-Cody et al.,2004).

Bifidobacteria are common inhabitants of the human gastrointestinal tract (GIT) and are used for probiotics applications in Functional Foods. Such strains have the potential to enhance CLA levels in dairy products during fermentation, being used as either starters or adjunct cultures. In this study we assessed the ability of previously identified bacterial strains to generate CLA from linoleic acid.

Of the strains tested, the propionibacteria and the bifidobacteria generated CLA from linoleic acid. A number of the bifidobacteria strains investigated produced mainly c9, t11 CLA isomer following incubation in 0.55 mg ml-1 linoleic acid. This screening programme indicated that there was considerable inter-species variation in the ability of bifidobacteria to produce CLA isomers.

The t9, t11 CLA isomer was also generated, but at much lower levels. In an attempt to identify more robust and technologically viable strains of CLA-producing bifidobacteria, a study was conducted to isolate strains from the stools of (a) healthy human babies, (b) healthy adults and (c) elderly patients. The screening programme identified novel efficient CLA-producing Bifidobacterium strains, including B. breve, B. infantis, B. dentium, B. longum and B. catenulatum.

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Reported by

Moorepark Food Research Centre, Fermoy,