Novel Pathway for Corrinoid Compounds Production in Lactobacillus

Biological properties of vitamin B12

Vitamin B12, cobalamin, is indispensable for humans owing to its participation in two biochemical reactions: the conversion of l-methylmalonyl coenzyme A to succinyl coenzyme A, and the formation of methionine by methylation of homocysteine. Eukaryotes, encompassing plants, fungi, animals and humans, do not synthesise vitamin B12, in contrast to prokaryotes. Humans must consume it in their diet. The most important sources include meat, milk and dairy products, fish, shellfish and eggs. Due to this, vegetarians are at risk to develop a vitamin B12 deficiency and it is recommended that they consume fortified food. Vitamin B12 behaves differently to most vitamins of the B complex in several aspects, e.g. it is more stable, has a very specific mechanism of absorption and is stored in large amounts in the organism. This review summarises all its biological aspects (including its structure and natural sources as well as its stability in food, pharmacokinetics and physiological function) as well as causes, symptoms, diagnosis (with a summary of analytical methods for its measurement), prevention and treatment of its deficiency, and its pharmacological use and potential toxicity.

Lettuce fortification through vitamin B12-producing bacteria - proof of concept study

BACKGROUND

Vitamin B12 (cobalamin) can be produced de novo only by certain bacteria and archaea. It plays a crucial role in the health of animals and humans, which obtain it only through diet, mainly from animal products. This study aimed to identify endophytic bacterial strains capable of synthesizing vitamin B12 and enriching edible plants with it as a potential solution for vitamin B12 deficiency in vegetarians, vegans, and people with poor diets.

RESULTS

An in silico genome analysis was performed on 66 bacterial genomes, including the reference strain Pseudomonas denitrificans ATCC 13867, a known vitamin B12 producer. The genomes were analyzed using the Rapid Annotations using Subsystems Technology (RAST) server and the MetaCyc database to verify the presence and completeness of the vitamin B12 metabolic pathway. The ability of the strains to produce vitamin B12 was confirmed with a high-performance liquid chromatography with diode-array detection (HPLC-DAD) analysis of pure culture extracts. Eleven strains produced detectable amounts of vitamin B12 under tested conditions. The best performing candidates were further tested for their efficacy in producing vitamin B12 in lettuce grown under sterile conditions on Murashige and Skoog (MS) medium with or without CoCl2 supplementation. Methylobacterium sp. strain P1-11 produced detectable amounts of vitamin B12 in planta: 1.654 and 2.559 μg per g of dry weight without and with CoCl2 supplementation, respectively.

CONCLUSION

This is the first time a bacterial endophyte was used to produce vitamin B12 in planta, suggesting that bacterial endophytes could be utilized to enhance the nutraceutical values of plant-based foods. © 2025 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

The use of propionic and lactic acid bacteria to produce cobalamin and folate in injera, an Ethiopian cereal-based fermented food

Like in many developing countries, the traditional Ethiopian diet relies mainly on starchy staple foods and often lacks sufficient animal-sourced foods which are crucial for cobalamin intake. Furthermore, the concentration of folate in traditionally prepared injera, an Ethiopian cereal-based fermented staple food, is highly variable and injera contains biologically inactive corrinoids. This study aimed to improve the cobalamin and folate content of injera by using cobalamin-producing Propionibacterium freudenreichii and folate-producing Lactiplantibacillus plantarum strains, both individually and combined. Since injera is fermented using backslopping, we also assessed the ability of these strains to produce cobalamin and folate consistently across successive fermentation batches. Changes in the microbial ecosystem were monitored using real-time PCR. The theoretical contribution of the injera prepared using the selected strains to the cobalamin and folate intake of children and women of reproductive age was also calculated. Results showed that using the selected bacterial strains individually increased cobalamin (up to 19.2 μg/100 g of dry matter) and folate (up to 180.2 μg/100 g of dry matter) levels in the injera dough over several backslopping fermentation batches. Regular consumption of the injera with enhanced vitamin content produced using each strain alone would be capable of fulfilling the entire recommended nutrient intake for cobalamin and up to 29 % of the recommended intake for folate for children and women of reproductive age. However, when the strains were used together, the production of both vitamins was reduced. The presence of certain common endogenous bacterial species and genera exhibited significant variability, highlighting the complex response of the native microbiota to the different inoculation strategies employed. Future experiments should consider selecting a microbial consortium comprising non-competing microorganisms to ensure the simultaneous production of cobalamin and folate in fermented foods.

The Impact of Bioactive Molecules from Probiotics on Child Health: A Comprehensive Review

Background: This review investigates the impact of bioactive molecules produced by probiotics on child health, focusing on their roles in modulating gut microbiota, enhancing immune function, and supporting overall development. Key metabolites, including short-chain fatty acids (SCFAs), bacteriocins, exopolysaccharides (EPSs), vitamins, and gamma-aminobutyric acid (GABA), are highlighted for their ability to maintain gut health, regulate inflammation, and support neurodevelopment. Objectives: The aim of this review is to examine the mechanisms of action and clinical evidence supporting the use of probiotics and postbiotics in pediatric healthcare, with a focus on promoting optimal growth, development, and overall health in children. Methods: The review synthesizes findings from clinical studies that investigate the effects of probiotics and their metabolites on pediatric health. The focus is on specific probiotics and their ability to influence gut health, immune responses, and developmental outcomes. Results: Clinical studies demonstrate that specific probiotics and their metabolites can reduce gastrointestinal disorders, enhance immune responses, and decrease the incidence of allergies and respiratory infections in pediatric populations. Additionally, postbiotics-bioactive compounds from probiotic fermentation-offer promising benefits, such as improved gut barrier function, reduced inflammation, and enhanced nutrient absorption, while presenting fewer safety concerns compared to live probiotics. Conclusions: By examining the mechanisms of action and clinical evidence, this review underscores the potential of integrating probiotics and postbiotics into pediatric healthcare strategies to promote optimal growth, development, and overall health in children.

Cereal-based fermented foods as a source of folate and cobalamin: The role of endogenous microbiota

Folate (vitamin B9) and cobalamin (vitamin B12) deficiencies potentially affect millions of people worldwide, leading to different pathologies. In Ethiopia, the diet is characterized by high consumption of fermented cereal-based foods such as injera, a good source of folate but not of cobalamin, which is only found in foods of animal origin that are rarely consumed. Some of the bacteria responsible for the fermentation of cereals can synthesize cobalamin, but whether or not fermented cereal food products contain cobalamin remains underexplored. The objective of this study was to assess the folate and cobalamin content of injera collected from various households in Ethiopia at different stages of production. Global (16S rRNA gene sequencing) and specific (real-time PCR quantification of bacteria known for folate or cobalamin production) bacterial composition of these samples was assessed. UPLC-PDA was used to identify the cobalamin to see whether the active or inactive form was present. Surprisingly, teff flour contained 0.8 μg/100 g of cobalamin, most probably due to microbial contamination from the environment and the harvesting process. While fermentation increased the folate and cobalamin content in some households, their levels decreased in others. Conversely, cooking consistently reduced the level of the vitamins. Fresh injera contained, on average, 21.2 μg/100 g of folate and 2.1 μg/100 g of cobalamin, which is high, but with marked variation depending on the sample. However, the form of cobalamin was a corrinoid that is biologically inactive in humans. Injera fermentation was dominated by lactic acid bacteria, with significant correlations observed between certain bacterial species and folate and cobalamin levels. For example, a high proportion of Fructilactobacillus sanfranciscensis, a known folate consumer, was negatively correlated with the folate content of injera. On the contrary, Lactobacillus coryniformis, known for its cobalamin synthesis ability was present in high proportion in the cobalamin-rich samples. These findings highlight the complex interrelationship between microorganisms and suggest the involvement of specific bacteria in the production of folate and cobalamin during injera fermentation. Controlled fermentation using vitamin-producing bacteria is thus a promising tool to promote folate and cobalamin production in fermented food.

Metabolism Characteristics of Lactic Acid Bacteria and the Expanding Applications in Food Industry

Lactic acid bacteria are a kind of microorganisms that can ferment carbohydrates to produce lactic acid, and are currently widely used in the fermented food industry. In recent years, with the excellent role of lactic acid bacteria in the food industry and probiotic functions, their microbial metabolic characteristics have also attracted more attention. Lactic acid bacteria can decompose macromolecular substances in food, including degradation of indigestible polysaccharides and transformation of undesirable flavor substances. Meanwhile, they can also produce a variety of products including short-chain fatty acids, amines, bacteriocins, vitamins and exopolysaccharides during metabolism. Based on the above-mentioned metabolic characteristics, lactic acid bacteria have shown a variety of expanded applications in the food industry. On the one hand, they are used to improve the flavor of fermented foods, increase the nutrition of foods, reduce harmful substances, increase shelf life, and so on. On the other hand, they can be used as probiotics to promote health in the body. This article reviews and prospects the important metabolites in the expanded application of lactic acid bacteria from the perspective of bioengineering and biotechnology.

Microbial and Genetic Resources for Cobalamin (Vitamin B12) Biosynthesis: From Ecosystems to Industrial Biotechnology

Many microbial producers of coenzyme B12 family cofactors together with their metabolically interdependent pathways are comprehensively studied and successfully used both in natural ecosystems dominated by auxotrophs, including bacteria and mammals, and in the safe industrial production of vitamin B12. Metabolic reconstruction for genomic and metagenomic data and functional genomics continue to mine the microbial and genetic resources for biosynthesis of the vital vitamin B12. Availability of metabolic engineering techniques and usage of affordable and renewable sources allowed improving bioprocess of vitamins, providing a positive impact on both economics and environment. The commercial production of vitamin B12 is mainly achieved through the use of the two major industrial strains, Propionobacterium shermanii and Pseudomonas denitrificans, that involves about 30 enzymatic steps in the biosynthesis of cobalamin and completely replaces chemical synthesis. However, there are still unresolved issues in cobalamin biosynthesis that need to be elucidated for future bioprocess improvements. In the present work, we review the current state of development and challenges for cobalamin (vitamin B12) biosynthesis, describing the major and novel prospective strains, and the studies of environmental factors and genetic tools effecting on the fermentation process are reported.