16 Sep 2024 --- Germany-based researchers designed a two-stage “Power-to-Protein” bioreactor system that converts hydrogen, oxygen and CO2 into yeast rich in protein and vitamin B9 and runs on renewable energy. Only six grams or 0.4 tablespoons of the harvested dried yeast meets the daily vitamin B9 requirement, and 85 g or six tablespoons of yeast provides 61% of daily protein needs. In the first stage of production, the bacterium Thermoanaerobacter kivui converts hydrogen and CO2 into acetate, which is found in vinegar. Baker’s yeast, or Saccharomyces cerevisiae, feeds on this acetate and oxygen to produce protein and vitamin B9. The hydrogen and oxygen can be made by “zapping water with electricity” from clean energy sources such as windmills.