Phytase-based phosphorus recovery process for 20 distinct press cakes

20/04/2020
  Scheme for phytate degradation Copyright: © ACS Sustainable Chem. Eng. Direct phytase treatment of deoiled and milled press cakes leads to phytate (InsP6) hydrolysis and the release of phosphate

Plants store phosphorus (P) in the form of phytate in their seeds and grains. Press cakes (e.g., deoiled seeds of sunflower or rapeseed) are usually used in animal feeding, but monogastric animals like poultry or swine can barely utilize the P stored in phytate. As phytate accounts often for more than 1% of the seed dry weight, press cakes are a valuable resource for P recycling. We present a widely applicable process for phosphate recycling from plant biomass using the E. coli phytase AppA. Direct phytase treatment of press cakes yields in phosphate recovery rates of up to 3% (w/w) in aqueous suspension at close to ambient temperatures. This environmental friendly process was applicable to all 20 plant materials tested within this study.

The recovered P can be a sustainable substitute for rock mining and can be used as fertilizer or food and feed additive, e.g. in the form of polyphosphate. Large-scale application of this process on renewable resources would be a step towards a circular bioeconomy and would enable new and decentralized value chains.

This paper was written in the division Molecular Bioeconomy and was funded by Deutsche Bundesstiftung Umwelt (33006/01-32).

Herrmann, K., Ruff, A. J., Schwaneberg, U.; Phytase-Based Phosphorus Recovery Process for 20 Distinct Press Cakes; ACS Sustainable Chem. Eng., 2020. DOI 10.1021/acssuschemeng.9b07433