The fatty acid profile of vegetative Azotobacter vinelandii ATCC 12837: growth phase-dependence.
Fatty acids of Azotobacter vinelandii ATCC 12837 were determined at various times during aerobic vegetative growth at 30 degrees C to provide baseline data for studying the effects of chemical agents on the organism's survival and fatty acid biosynthesis. Palmitate (16:0) was the highest at 36.7+/-4.3 mol% (mean+/-SD) after the first 5 h in fresh culture, decreasing slightly to 33.4+/-2.6 mol% at 49 h. The other fatty acids were therefore each normalized as a ratio of 16:0. At 5 h, as a ratio of 16:0, myristate (14:0) was 0.14+/-0.06, palmitoleate (16:1cDelta9-10) 0.13+/-0.06, oleate (18:1cDelta9-10) 0.21+/-0.12, cis-vaccenate (18:1cDelta11-12) 0.30+/-0.17 and stearate (18:0) 0.68+/-0.02. As the growth phase advanced to 49 h, 14:0 and 16:1cDelta9-10 increased, 18:1cDelta9-10 decreased and cis-vaccenate reciprocally increased, whereas 18:0 decreased. These suggest that the saturated fatty acid biosynthesis pathway yielded 16:0 and 18:0 in the 5-h lag period. By desaturation, 18:0 formed the unsaturated fatty acid (UFA) 18:1cDelta9-10. As the culture aged, the anaerobic UFA biosynthesis pathway formed 16:1cDelta9-10, which was elongated to 18:1cDelta11-12. These fatty acid alterations represent a homeoviscous adaptation, modulating the microbe's membrane lipid viscosity for optimal cellular function.
Larsen
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A
Department of Chemistry, The University of Winnipeg, Winnipeg, Manitoba, R3B 2E9, Canada.
Sliskovic
I
I
Juric
D
D
Pinnock
C L
CL
Kullman
H
H
Segstro
E
E
Reinfelds
G
G
Eze
M O
MO
D016948:Azotobacter vinelandii / Q000254:growth & development / Q000378:metabolism*; D005227:Fatty Acids / Q000096:biosynthesis* / Q000302:isolation & purification; D005231:Fatty Acids, Unsaturated / Q000096:biosynthesis
D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated