March 25/Drug Week -- New research, "Optimization of a reconstituted skim milk based medium for enhanced CLA production by bifidobacteria," is the subject of a report. In this recently published article, scientists in Fermoy, Ireland, conducted a study "to determine the effect of a range of supplements on the bioconversion of linoleic acid to conjugated linoleic acid (CLA) by Bifidobacterium breve NCIMB 702258 in reconstituted skim milk (RSM). Seven supplements (yeast extract, casein hydrolysate, tryptone, l-cysteine hydrochloride, sodium acetate, sodium butyrate and sodium propionate) were identified as increasing the bioconversion of linoleic acid to c9, t11 CLA."

"Using these supplements, the percentage bioconversion of linoleic acid (0.35mg ml(-l)) to the c9, t11 CLA isomer was elevated from 15.5 ±1.1% in 20% RSM (w/v) to 48.1 ±2.2% in the supplemented RSM. Through additional supplementation of 20mg m1(-1) inulin and optimization of inoculum and linoleic acid concentration, the percentage bioconversion to c9, t11 CLA was increased to 55.0 +3.2%. Through supplementation, the concentration of CLA produced by bifidobacteria in RSM can be increased to levels comparable to those observed in the synthetic medium cys-MRS. AND IMPACT OF THE STUDY: The impact of 22 supplements on the production of the c9, t11 CLA isomer by the strain B. breve NCIMB 702258 in milk has been determined," wrote A.A. Hennessy and colleagues, Fermoy, Co.

The researchers concluded, "The results provide an understanding of the factors, which influence CLA production by bifidobacteria in RSM."

Hennessy and colleagues published their study in the Journal of Applied Microbiology ("Optimization of a reconstituted skim milk based medium for enhanced CLA production by bifidobacteria." Journal of Applied Microbiology, 2009;106(4):1315-27).

For more information, contact A.A. Hennessy, TEAGASC, Biotechnology Centre, Moorepark Food Research Centre, Fermoy, Co. Cork, Ireland.

From the March 30, 2009, Prepared Foods E-dition