Institut Francais Du Petrole, Des Carburants Et Lubrifiants Et

Institut Francais Du Petrol, Des Carburants Et Lubrifiants Et Entreprise

Georges Glikmans

Paul Maldonado

Max Charpentier

Gaetan Sylvestre

Jean-Max Charpentier

Claude Gaillaridin

This invention relates to the production of citric and/or isocitric acids. The production of citric and/or isocitric acids is effected by cultivating a citric and/or isocitric acid-producing yeast in a culture medium containing a compound selected from cyanoacetic acid, and organic and inorganic derivatives thereof. Increased yields of citric and isocitric acids are obtained using a process in accordance with the invention, preferably using a yeast of the genus Candida.

Chemical process

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.

Method of preparing yeasts enriched in L-lysine and capable of excreting

Process for manufacturing citric acid by aerobic culture of yeast strains in a medium containing at least one n-paraffin, comprising adding to the culture medium, after the phase of exponential growth thereof, a nitrogenous heterocyclic organic compound selected from .alpha.-picolinic acid, 2,6-dipicolinic acid, quinaldic acid, bi-pyridine, orthophenanthroline, 8-hydroxyquinoline and 5-hydroxyquinoxaline, at a concentration from 0.5 to 10 g/liter, and controlling the pH value of said medium during said growth phase by addition of sodium or potassium carbonate.

Growing community of inventors

Meudon la Foret, France

Georges Glikmans