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ARS Home » Northeast Area » Ithaca, New York » Robert W. Holley Center for Agriculture & Health » Research » Publications at this Location » Publication #108536
Title: FACTORS AFFECTING THE CONJUGATED LINOLEIC ACID (CLA) PRODUCTION OF BUTYRIVIBRIO FIBRISOLVENS

Author
item KIM, YOUNG-JUN - CORNELL UNIVERSITY
item LIU, RUI - CORNELL UNIVERSITY
item BOND, D - CORNELL UNIVERSITY
item Russell, James
item DIEZ-GONZALEZ, FRANCISCO - CORNELL UNIVERSITY
item JARVIS, GRAEME - CORNELL UNIVERSITY

Submitted to: International Food Technology Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/11/2000
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Conjugated linoleic acid (CLA) is an anti-carcinogenic compound that is found in dairy foods. CLA is an intermediate in biohydrogenation, but CLA can accumulate in the rumen. The mechanism of the accumulation was not understood. This study was designed to determine the mechanism of CLA production by the ruminal bacterium Butyrivibrio fibrisolvens A38 and to identify strategies for increasing CLA production. B. fibrisolvens was incubated under a variety of conditions and fatty acids including CLA were extracted and analyzed by gas chromatography. Exponentially growing cultures incubated with linoleic acid (C18:2) produced less CLA than stationary phase cells, and the glycolytic inhibitor, iodoacetate, increased the CLA production of cells incubated anaerobically. Stationary phase cells incubated aerobically produced more CLA than those incubated anaerobically, and CLA production and biohydrogenation were always inversely related. CLA was produced very rapidly, but washed cells pre-incubated with CLA did not produce additional CLA. CLA accumulation was a linear function of the cell density. These results indicated that C18:2 isomerase could not continually recycle to produce more CLA. Cultures that were gradually adapted to LA produced less CLA, and more of the C18:2 was converted to trans-vaccenic acid (trans- C18:1). These results supported the idea that C18:2 isomerase and D-9 saturase reactions of fatty acid biohydrogenation were obligatory linked. Growing cultures of B. fibrisolvens did not produce significant amounts of CLA until the C18:2 concentration was high, biohydrogenation was arrested, and the cell density had declined.