Method of preparing yeasts enriched in L-lysine and capable of excreting organic acids
 A method of preparing a yeast enriched in L-lysine and capable of excreting an organic acid, such as citric acid, and possibly also isocitric and glutamic acids, when cultivated on a hydrocarbon-containing medium comprises subjecting a yeast of the species Candida lipolytica to the action of a mutagenic agent, such as a chemical agent or radiation, cultivating the thus-treated yeast in a culture medium containing a lysine analogue, preferably that to which the original yeast is most sensitive, in a concentration which is about 50 to 100 times greater than that to which the cells of the original yeast are most sensitive, and cultivating the resultant mutated resistant yeast on a medium containing at least one hydrocarbon such as a C.sub.10 -C.sub.20 normal paraffin as well as conventional nutrients, the cultivation preferably being effected in an agitated aerated medium at a pH of 3 to 6 and a temperature of 25.degree. to 30.degree. C.. The yeast enriched in L-lysine may be recovered from the reaction medium as a useful product and citric acid and other acids may be recovered in conventional manner from the reaction medium. 
Institut Francais du Petrol, des Carburants et Lubrifiants et Entreprise de Recherches et d'Activities Petrolieres Elf
C C C Y C
C12P C12P C12P Y10S C12N
inventional inventional inventional additional inventional
Paul Gaetan Georges Claude
Maldonado Sylvestre Glikmans Gaillaridin