Bio-enrichment of vitamin B12 in plant-based food via fermentation

Vitamin B12 deficiency is common among individuals following strictly plant-based diets. This issue is amplified by the growing preference for organic products, which are often not vitamin-fortified. As vitamin B12 is naturally produced by bacteria, fermentation offers a sustainable strategy to enrich plant-based foods. This study explored the potential of vitamin B12–producing bacteria to enhance B12 content in plant-based matrices. Lactobacillus strains were screened for their ability to synthesize vitamin B12 in a B12-free medium. The most effective strains were further tested alone and in co-culture with Propionibacterium strains in oat-based food matrices. Vitamin B12 levels were quantified using microbiological assays and HPLC-MS/MS during both strain selection and fermentation. Additionally, genetic analyses were conducted to investigate gene clusters involved in B12 biosynthesis and their regulation. Only a limited number of Lactobacillus strains produced biologically active vitamin B12, and only with added precursors. Despite having complete biosynthetic genes, some strains failed to produce active B12 in vitro and in food. Co-fermentation with Propionibacterium increased and accelerated B12 production compared to monocultures, while also moderating acidification and improving vitamin stability. Overall, this study demonstrates that co-fermentation is a promising, sustainable approach to enhance vitamin B12 in plant-based foods such as oat-based beverages. This strategy supports the development of organic products compliant with EU Regulation 2018/848, which restricts chemically synthesized additives.

Level thesis:degree_level

thesis.doctoral

Grantor dc:publisher

Christian-Albrechts-Universität zu Kiel

Year

2026

Author dc:creator

• Gao, Lu

Contributors dc:contributor

• Franz, Charles
• Pichner, Rohtraud

• Vitamin B12 biosynthesis
• Plant-based diets
• Lactic acid bacteria
• Propionibacterium
• Co-culture fermentation
• Oat-based matrices
• Bio-enrichment
• Vitamin-B12-Biosynthese
• Bioanreicherung
• Lactobacillus
• Co-Kultur-Fermentation
• Pflanzenbasierte Ernährung
• Vegane Ernährung

Repository record source_url

https://macau.uni-kiel.de/receive/macau_mods_00008222

OAI identifier oai:identifier

oai:macau.uni-kiel.de:macau_mods_00008222