Human Intrinsic Factor Expression for Bioavailable Vitamin B₁₂ Enrichment in Microalgae

Area of Science:

• Biotechnology
• Nutritional Science
• Microalgal Cultivation

Background:

• Dietary supplements and functional foods increasingly incorporate microalgae.
• Vitamin B12 (cobalamin) is essential but microalgae do not naturally produce it, leading to variable B12 content.
• Bioavailability of B12 from microalgae for human consumption is a concern.

Purpose of the Study:

• To investigate the feasibility of using human intrinsic factor (IF) to enrich microalgae with bioavailable vitamin B12.
• To engineer *Chlamydomonas reinhardtii* for the expression and secretion of functional IF.

Main Methods:

• Genetic engineering of *Chlamydomonas reinhardtii* to express human intrinsic factor (IF).
• Utilizing an N-terminal ARS2 signal peptide for efficient secretion of IF into the growth medium.
• Assessing the co-abundance of secreted IF and vitamin B12 to infer functionality.

Main Results:

• Successful expression and secretion of functional human intrinsic factor (IF) from *Chlamydomonas reinhardtii*.
• Evidence of IF's functionality through co-abundance with vitamin B12 in the medium.
• Demonstrated potential for controlled B12 enrichment in microalgae.

Conclusions:

• Engineered microalgae expressing intrinsic factor can be a viable strategy for producing vitamin B12-enriched biomass.
• This approach could lead to a controlled and potentially more bioavailable source of vitamin B12 for human diets, especially for vegetarians.
• Microalgae represent a promising platform for producing fortified foods and supplements with essential nutrients.