TY - JOUR
T1 - Effect of linoleic acid concentration on conjugated linoleic acid production by Butyrivibrio fibrisolvens A38
AU - Young Jun Kim, Jun Kim
AU - Rui Hai Liu, Hai Liu
AU - Bond, D. R.
AU - Russell, J. B.
PY - 2000
Y1 - 2000
N2 - Butyrivibrio fibrisolvens A38 inocula were inhibited by as little as 15 μM linoleic acid (LA), but growing cultures tolerated 10-fold more LA before growth was inhibited. Growing cultures did not produce significant amounts of cis-9, trans-11 conjugated linoleic acid (CLA) until the LA concentration was high enough to inhibit biohydrogenation, growth was inhibited, and lysis was enhanced. Washed-cell suspensions that were incubated anaerobically with 350 μM LA converted most of the LA to hydrogenated products, and little CLA was detected. When the washed-cell suspensions were incubated aerobically, biohydrogenation was inhibited, CLA production was at least twofold greater, and CLA persisted. The LA isomerase reaction was very rapid, but the LA isomerase did not recycle like a normal enzyme to catalyze more substrate. Cells that were preincubated with CLA lost their ability to produce more CLA from LA, and the CLA accumulation was directly proportional (r2 = 0.98) to the initial cell density. Growing cells were as sensitive to CLA as LA, the LA isomerase and reductases of biohydrogenation were linked, and free CLA was not released. Because growing cultures of B. fibrisolvens A38 did not produce significant amounts of CLA until the LA concentration was high, biohydrogenation was arrested, and the cell density had declined, the flow of CLA from the rumen may be due to LA-dependent bacterial inactivation, death, or lysis.
AB - Butyrivibrio fibrisolvens A38 inocula were inhibited by as little as 15 μM linoleic acid (LA), but growing cultures tolerated 10-fold more LA before growth was inhibited. Growing cultures did not produce significant amounts of cis-9, trans-11 conjugated linoleic acid (CLA) until the LA concentration was high enough to inhibit biohydrogenation, growth was inhibited, and lysis was enhanced. Washed-cell suspensions that were incubated anaerobically with 350 μM LA converted most of the LA to hydrogenated products, and little CLA was detected. When the washed-cell suspensions were incubated aerobically, biohydrogenation was inhibited, CLA production was at least twofold greater, and CLA persisted. The LA isomerase reaction was very rapid, but the LA isomerase did not recycle like a normal enzyme to catalyze more substrate. Cells that were preincubated with CLA lost their ability to produce more CLA from LA, and the CLA accumulation was directly proportional (r2 = 0.98) to the initial cell density. Growing cells were as sensitive to CLA as LA, the LA isomerase and reductases of biohydrogenation were linked, and free CLA was not released. Because growing cultures of B. fibrisolvens A38 did not produce significant amounts of CLA until the LA concentration was high, biohydrogenation was arrested, and the cell density had declined, the flow of CLA from the rumen may be due to LA-dependent bacterial inactivation, death, or lysis.
UR - http://www.scopus.com/inward/record.url?scp=0034469731&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0034469731&partnerID=8YFLogxK
U2 - 10.1128/AEM.66.12.5226-5230.2000
DO - 10.1128/AEM.66.12.5226-5230.2000
M3 - Article
C2 - 11097894
AN - SCOPUS:0034469731
SN - 0099-2240
VL - 66
SP - 5226
EP - 5230
JO - Applied and environmental microbiology
JF - Applied and environmental microbiology
IS - 12
ER -