title: Hydrogenation of unsaturated fatty acids by Treponema (Borrelia) strain B 2 5, a rumen spirochete.
abstract: The time course of hydrogenation of linoleic acid to trans-11-octadecenoic acid was observed in a growing culture of Treponema (Borrelia) strain B(2)5. A conjugated fatty acid, cis-9, trans-11-octadecadienoic acid, was identified as an intermediate in the process. The isomerase responsible for the conversion of linoleic acid to the conjugated fatty acid was found to be associated with a particulate fraction characterized by a high protein and lipid content in a 2:1 ratio. Optimum pH for isomerase activity was found to be 7.0 in 0.05 m potassium phosphate buffer. No cofactor requirements could be demonstrated for the isomerase. The sulfhydryl inhibiting agents, iodoacetamide, N-ethylmaleimide, and p-chloromercuribenzoate, inhibited isomerase activity. Isomerase activity was also inhibited by the metal chelators, o-phenanthroline, alpha, alpha'-bipyridyl, ethylenediaminetetraacetic acid, and 8-hydroxyquinoline. Linoleic (Delta9, 12), linolenic (Delta9, 12, 15), and gamma-linolenic (Delta6, 9, 12) acids served as effective substrates for the isomerase; however, the derivatives of linoleic and linolenic acid did not.
mesh_terms: D000818:Animals; D002021:Buffers; D002247:Carbon Isotopes; D002417:Cattle; D002499:Centrifugation, Density Gradient; D002614:Chelating Agents / Q000494:pharmacology; D002845:Chromatography; D002849:Chromatography, Gas; D002855:Chromatography, Thin Layer; D003470:Culture Media; D005227:Fatty Acids / Q000032:analysis / Q000096:biosynthesis; D005782:Gels; D006863:Hydrogen-Ion Concentration; D006865:Hydrogenation; D007259:Infrared Rays; D007535:Isomerases / Q000037:antagonists & inhibitors / Q000302:isolation & purification / Q000378:metabolism; D008041:Linoleic Acids / Q000378:metabolism*; D012417:Rumen / Q000382:microbiology*; D012822:Silicon Dioxide; D012997:Solvents; D013053:Spectrophotometry; D013057:Spectrum Analysis; D013395:Sucrose; D013439:Sulfhydryl Reagents / Q000494:pharmacology; D014208:Treponema / Q000201:enzymology / Q000254:growth & development / Q000378:metabolism*; D014461:Ultracentrifugation; D014466:Ultraviolet Rays
chemical_list: D002021:Buffers; D002247:Carbon Isotopes; D002614:Chelating Agents; D003470:Culture Media; D005227:Fatty Acids; D005782:Gels; D008041:Linoleic Acids; D012997:Solvents; D013439:Sulfhydryl Reagents; D013395:Sucrose; D012822:Silicon Dioxide; D007535:Isomerases