Effect of the amount of cobalt added to the fermentation medium on the productivity of vitamin B12 from cheese whey by Propionibacterium freudenreichii. مجلة الجامعة [Internet]. 2021 Jan. 28 [cited 2026 Jun. 6];3(12). Available from: https://journal.hama-univ.edu.sy/huj/article/view/514