TY - JOUR
T1 - Metabolism of conjugated linoleic acids and 18:1 fatty acids by ruminal bacteria
T2 - products and mechanisms
AU - McKain, Nest
AU - Shingfield, Kevin J.
AU - Wallace, R. John
N1 - DA - 20100205 IS - 1465-2080 (Electronic) IS - 1350-0872 (Linking) LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't RN - 0 (Dietary Fats) RN - 0 (Fatty Acids) RN - 0 (Fatty Acids, Unsaturated) RN - 0 (Linoleic Acids, Conjugated) SB - IM
PY - 2010/2
Y1 - 2010/2
N2 - Cultures of ruminal bacteria known to metabolize unsaturated fatty acids were grown in medium containing 50 mu g ml(-1) of geometric and positional isomers of conjugated linoleic acid (CLA) or 18: 1 fatty acids and 37.4% deuterium oxide to investigate the mechanisms responsible for fatty acid metabolism. Butyrivibrio fibrisolveris JW11 converted cis-9,trans-11-18: 2 and trans-9,trans-11-18: 2 to trans-11-18: 1 as the main product, labelled at C-9, and metabolized trans-10, cis-12-18 : 2 to trans-10-18: 1, labelled at C-13, and smaller amounts of trans-12-18 : 1 and cis-12-18 : 1. Butyrivibrio proteoclasticus P-18 did not grow in the presence of cis-9,trans-11-18: 2 or trans-10, cis-12-18 : 2, but grew in medium containing trans-9, trans-11-18 : 2, forming 18 : 0. Propionibacterium acnes, a ruminal species that isomerizes linoleic acid to trans-10, cis-12-18: 2, did not metabolize CLA isomers further. B. fibrisolvens metabolized small amounts of trans-10-18: 1, trans-11-18: 1 and cis-9-18 : 1, but the products formed were not detected. B. proteoclasticus, on the other hand, carried out substantial conversion of 18: 1 substrates to 18: 0. P. acnes hydrated cis-9-18 : 1 and trans-11-18: 1 to 10-OH-18: 0, which was further oxidized to yield 10-O-18:0. The deuterium enrichment in the intermediates formed during incubations with 9,111 geometric isomers of CLA was about half that of the products from trans-10, cis-12 CLA and 18: 1 isomers, suggesting that the reduction of 9,11 geometric isomers CLA by ruminal bacteria occurs via different mechanisms compared with the metabolism of other unsaturated fatty acids.
AB - Cultures of ruminal bacteria known to metabolize unsaturated fatty acids were grown in medium containing 50 mu g ml(-1) of geometric and positional isomers of conjugated linoleic acid (CLA) or 18: 1 fatty acids and 37.4% deuterium oxide to investigate the mechanisms responsible for fatty acid metabolism. Butyrivibrio fibrisolveris JW11 converted cis-9,trans-11-18: 2 and trans-9,trans-11-18: 2 to trans-11-18: 1 as the main product, labelled at C-9, and metabolized trans-10, cis-12-18 : 2 to trans-10-18: 1, labelled at C-13, and smaller amounts of trans-12-18 : 1 and cis-12-18 : 1. Butyrivibrio proteoclasticus P-18 did not grow in the presence of cis-9,trans-11-18: 2 or trans-10, cis-12-18 : 2, but grew in medium containing trans-9, trans-11-18 : 2, forming 18 : 0. Propionibacterium acnes, a ruminal species that isomerizes linoleic acid to trans-10, cis-12-18: 2, did not metabolize CLA isomers further. B. fibrisolvens metabolized small amounts of trans-10-18: 1, trans-11-18: 1 and cis-9-18 : 1, but the products formed were not detected. B. proteoclasticus, on the other hand, carried out substantial conversion of 18: 1 substrates to 18: 0. P. acnes hydrated cis-9-18 : 1 and trans-11-18: 1 to 10-OH-18: 0, which was further oxidized to yield 10-O-18:0. The deuterium enrichment in the intermediates formed during incubations with 9,111 geometric isomers of CLA was about half that of the products from trans-10, cis-12 CLA and 18: 1 isomers, suggesting that the reduction of 9,11 geometric isomers CLA by ruminal bacteria occurs via different mechanisms compared with the metabolism of other unsaturated fatty acids.
KW - oleic-acid
KW - milk-fat
KW - rumen bacteria
KW - clostridium-proteoclasticum
KW - 10-ketostearic acid
KW - stearic-acid
KW - sheep rumen
KW - in-vitro
KW - fish-oil
KW - biohydrogenation
U2 - 10.1099/mic.0.036442-0
DO - 10.1099/mic.0.036442-0
M3 - Article
VL - 156
SP - 579
EP - 588
JO - Microbiology
JF - Microbiology
SN - 1350-0872
IS - 2
ER -