Kumari M, Bhushan B, Kokkiligadda A, Kumar V, Behare P, Tomar SK. Vitamin B12 biofortification of soymilk through optimized fermentation with extracellular B12 producing
Lactobacillus isolates of human fecal origin.
Curr Res Food Sci 2021;
4:646-654. [PMID:
34585144 PMCID:
PMC8455482 DOI:
10.1016/j.crfs.2021.09.003]
[Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 09/06/2021] [Accepted: 09/09/2021] [Indexed: 11/25/2022] Open
Abstract
The present study was designed to bio-fortify the soymilk (per se a B12-free plant food matrix). The PCR-based screening characterized the human fecal samples (4 out of 15 tested) and correspondingly identified novel lactobacilli isolates (n = 4) for their B12 production potential and rest (n = 62) as negative for this attribute. Further, 3 out of the 4 selected strains showed ability for extracellular vitamin production. The most prolific strain, Lactobacillus reuteri F2, secreted B12 (132.2 ± 1.9 μg/L) in cobalamin-free-medium with the highest ratio ever reported (0.97:1.00; extra-: intra-cellular). In next stage, the soymilk was biofortified in situ with B12 during un-optimized (2.8 ± 0.3 μg/L) and optimized (156.2 ± 3.6 μg/L) fermentations with a ∼54-fold increase at Artificial Neuro Fuzzy Inference System based R value of >0.99. The added-nutrients, temperature and initial-pH were observed to be the most important fermentation variables for maximal B12 biofortification. We report Lactobacillus rhamnosus F5 as the first B12 producing (101.7 ± 3.4 μg/L) strain from this species. The cyanocobalamin was extracted, purified and separated on UFLC as nutritionally-relevant B12. Besides, the vitamin was bioavailable in an auxotrophic-mutant. The lactobacilli fermentation is suggested, therefore, as an effective approach for B12 biofortification of soymilk.
PCR-based real-time screening of human fecal samples for the presence of B12-related cbiK gene.
Novel report of B12 production in Lactobacillus rhamnosus species (strain F5).
A rare B12-producing phenotype of Lactobacillus reuteri F2 with highest ever ratio of extracellular vs total B12 (0.95:1.0).
Sequential optimization (OFAT .→ GSD → ANFIS) enhanced post-fermentation soymilk B12 levels by 54-folds.
One serving size (100 mL) of L. reuteri F2-biofortified fermented soymilk offered 6.5-fold higher B12 than human RDA.
The produced B12 form is nutritionally-relevant and biologically active for humans.
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