Speaker
Description
Vitamin B₁₂ (cobalamin) is essential for animal and human metabolism, while plants neither synthesize nor require it. Yet, aquatic plants such as duckweeds can accumulate bioavailable B₁₂ synthesized by their endophytic microbiome. We hypothesized that cobalt, the central metal ion in cobalamin would enhance B₁₂ accumulation by altering endophytic community structure and function. To test our hypothesis, we cultivated the rooted duckweed species Lemna minor and Spirodela polyrhiza and the rootless species Wolffia globosa across a cobalt gradient, ranging from 0 to 1 µM (just below the reported toxicity threshold). We quantified growth and bioavailable B12, profiled the corresponding endophytic bacterial communities and examined B₁₂ partitioning between roots and fronds.
Responses to cobalt were species-specific. In L. minor, B₁₂ increased by up to fivefold without affecting growth rate. Cobalt explained 54% of the variation in bacterial community composition and significantly altered the abundance of Novosphingobium and Roseomonas. In S. polyrhiza, B₁₂ increased by up to threefold, while cobalt explaining 38% of the variation in community composition and significantly influencing alpha diversity and overall community structure. In W. globosa, B₁₂ increased significantly at the highest cobalt concentration without detectable changes in community composition, suggesting regulation through microbial activity rather than taxonomic replacement. B₁₂ localization was also species-specific, with significantly greater accumulation in the roots of S. polyrhiza than in those of L. minor. These findings demonstrate that cobalt enhances microbiome derived B₁₂ accumulation in duckweed and provides a practical strategy for improving the nutritional value of duckweed biomass.
Keywords
Cobalamin Endophytic microbiome Cobalt supplementation
References
None
| Corresponding author email | daliarishmawi@gmail.com |
|---|---|
| Scientific Session | Microbiome & Interactions |
