Renewable Phytase Biocatalyst to Transform Biorefinery Waste Streams into Phosphorus Resources.
Journal:
Environmental science & technology
Published Date:
Jan 5, 2026
Abstract
Phosphorus (P) recovery is crucial for sustaining the global food supply and preventing freshwater pollution. Biorefinery waste streams have emerged as promising, yet underexplored sources for P recovery. Here, we presented a renewable and robust cell surface-displayed Escherichia coli phytase (SDEcP) biocatalyst to convert organic P into inorganic P, thereby facilitating efficient phosphate recovery from biorefinery waste. This biocatalyst exhibited high enzyme activity (137.6 ± 3.7 U per gram of dry cell weight), maximal phosphate production rate of 75.3 ± 2.3 μM min-1, consistent full activity after 36 days, and simple regeneration via cell cultivation. We leveraged a machine learning-based approach to obtain SDEcP variants with up to 55% increase in enzyme activity and robustness for phytate conversion from real-world light steepwater. Selective phosphate recovery from SDEcP-treated steepwater was achieved by using agarose beads functionalized with phosphate-binding proteins, thus demonstrating a complete waste-to-value pathway. This study advances the development of new biocatalytic approaches for achieving a circular P economy.
