Metabolism of fatty acid in yeast: addition of reducing agents to the reaction medium influences beta-oxidation activities, gamma-decalactone production, and cell ultrastructure in Sporidiobolus ruinenii cultivated on ricinoleic acid methyl ester.
The sensitivity of Sporidiobolus ruinenii yeast to the use of reducing agents, reflected in changes in the oxidoreduction potential at pH 7 (Eh7) environment, ricinoleic acid methyl ester catabolism, gamma-decalactone synthesis, cofactor level, beta-oxidation activity, and ultrastructure of the cell, was studied. Three environmental conditions (corresponding to oxidative, neutral, and reducing conditions) were fixed with the use of air or air and reducing agents (hydrogen and dithiothreitol). Lowering Eh7 to neutral conditions (Eh7 = +30 mV and +2.5 mV) favoured the production of lactone more than the more oxidative condition (Eh7 = +350 mV). In contrast, when a reducing condition was used (Eh7 = -130 mV), the production of gamma-decalactone was very low. These results were linked to changes in the cofactor ratio during lactone production, to the beta-oxidation activity involved in decanolide synthesis, and to ultrastructural modification of the cell.
Laboratoire de microbiologie, UMR INRA-UB 1232, INRA, 17 rue Sully, B.P. 86510, F-21065 Dijon, France. Gilles.Feron@dijon.inra.fr
Gilles
G
Feron
Geneviève
G
Mauvais
Jeanine
J
Lherminier
Joël
J
Michel
Xiao-Dong
XD
Wang
Christophe
C
Viel
Rémy
R
Cachon
D001487:Basidiomycota / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004952:Esters; D005227:Fatty Acids / Q000378:metabolism*; D007783:Lactones / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D015394:Molecular Structure; D010084:Oxidation-Reduction / Q000187:drug effects; D019163:Reducing Agents / Q000494:pharmacology*; D012277:Ricinoleic Acids / Q000737:chemistry / Q000378:metabolism*
D003470:Culture Media; D004952:Esters; D005227:Fatty Acids; D007783:Lactones; D019163:Reducing Agents; D012277:Ricinoleic Acids; C109757:decan-4-olide; C030521:ricinoleic acid