Concurrent high production of natural folate and vitamin B12 using a co-culture process with Lactobacillus plantarum SM39 and Propionibacterium freudenreichii DF13

In this study, a high folate producer Lactobacillus plantarum SM39 was cultured in combination with a vitamin B12 producer, Propionibacterium freudenreichii DF13. The co-culture process was optimized to produce high levels of both vitamins in a whey permeate medium supplemented with yeast extract (SWP). Addition of 5 mg/L cobalt chloride, 15 mg/L DMBI, and 10 mg/L pABA to SWP medium followed by a two-step fermentation under optimal conditions, i.e. three days anaerobic/four days aerobic, led to high vitamin B12 and folate yields, 751 ± 353 ng/mL and 8399 ± 784 ng/mL, respectively. Folate yields were more than 10-fold higher than maximum values reported for natural fermentations and comparable to levels recently achieved using a genetically optimized strain. The controlled addition of pABA and cobalt offers the possibility to produce a vitamin supplement with a suitable balance of folate and vitamin B12 of 170-1. The fermented medium containing high levels of natural folate and vitamin B12 content could be used to fortify foods with natural vitamins or as a nutritional supplement.