Phytase-Based Phosphorus Recovery Process for 20 Distinct Press Cakes

Abstract

Biomass from crop-processing such as deoiled seeds, grains, and nuts are phosphorus-rich raw materials with a hidden potential for recycling of the valuable element. Phytate as a phosphorus storage form accounts often for more than 1% of the dry weight. Herein, we report a broadly applicable process for the recycling of phosphate from plant biomass utilizing phytase enzymes. Phytase-based hydrolysis of phytate in an aqueous suspension at an energetically favorable temperature of 37 °C releases amounts of phosphate that are >20 mg/g press cake and is applicable to all 20 different press cakes and meals tested. Due to the high annual amount of processed press cakes from soybean, rapeseed, and sunflower seed, these are well-suited for phosphorus recovery, with the potential to cover up to 80% (1 million ton) of the worldwide demand for food and feed applications. The recovered phosphate is free of heavy-metal impurities and could be used as a green fertilizer in organic farming or for the biotechnological production of polyphosphates. Valorization of press cakes by recycling phosphate using phytase enzymes is an environment-friendly process for the sustainable production of P-based value-added products in a circular bioeconomy.