Richter Gedeon Vegyeszeti Gyar Rt

Tade Vajda

Karoly Polinszky

Laszlo Szemler

Erzsebet Kovacs Nee Komoroczy

Tamas Szontagh

Bela Johan

Denes Szekely

Laszlo Kuti

Judit Bekes Nee Erdos

Emilia Simonovits Nee Czink

Janos Fulop

Laszlo Szabo

Robert Toros

Karoly Seitz

Aniko Hargital Nee Franyo

The invention relates to a method for increasing the vitamin B.sub.12 production of fermentation processes performed in a known way with a mixed population of mesophilic methane-producing bacteria under anaerobic conditions. According to the invention in an enrichment period of preferably 4 to 7 days a nutrient concentrate containing mainly inorganic ammonium compounds as nitrogen source and mainly methanol as carbon source and having a N:C weight ratio of 1:10 to 1:20, preferably 1:11 to 1:15 is added in daily portions to a fermentation broth obtained from a usual vitamin B.sub.12 fermentation process and containing living bacterium populations so as to increase the total concentration of assimilable nitrogen by a factor of maximum 4 until the end of the enrichment period, and thereafter the fermentation is terminated and the obtained fermentation broth with an increased vitamin B.sub.12 content is processed, or the fermentation is continued by periodically removing a portion of the fermentation broth and supplementing it with a same volume of fresh nutrient medium containing mainly inorganic ammonium compounds as nitrogen source and mainly methanol as carbon source and having a N:C weight ratio of 1:10 to 1:20, preferably 1:11 to 1:15. By this process fermentation broths with as high vitamin B.sub.12 concentration as 40.000 mcg./l. can be obtained.

Method for increasing the vitamin B.sub.12 production in fermentation

Growing community of inventors

Budapest, Hungary

Tade Vajda