Background and Objective: Phytase is a phosphatase enzyme. It is essential for hydrolyzing phytic acid, an antiNUTRIENT present in plant-based foods that chelates essential minerals and limits their BIOAVAILABILITY. Enzyme techniques used to improve phytase characteristics are discussed including thermostability, catalytic efficiency, and substrate specificity. Results and Conclusion: Phytase efficiency has been significantly improved for industrial applications by different engineering methods, including rational design, computational modeling, directed evolution, glycosylation engineering and semi-rational design. The study further highlights the application of phytase in food processing, including breadmaking, fermented foods, and functional food formulations, to address mineral deficiencies. Future advances in enzyme engineering, such as computational de novo design and enzyme immobilization, could expand commercial and nutritional uses of phytase. The focus of ongoing research on thermostable and highly efficient phytase variants provides significant possibilities for enhancing global food security and sustainability.

Because different phosphorus (P) forms vary greatly in their BIOAVAILABILITY, total phosphorus concentrations are a problematic predictor of the eutrophication potential of natural surface waters and wastewater treatment facility effluents. It is currently not known which operational P characterizations (i.e., dissolved/particulate and reactive/non-reactive) best predict effluent P BIOAVAILABILITY. We characterized the P speciation and directly measured the BIOAVAILABILITY of P (BAP) using algal bioassays for 14 full-scale advanced NUTRIENT removal wastewater treatment plants representing a wide range of P removal technologies. A strong statistical relationship was observed between the effluent total BAP (tBAP) and total reactive P (TRP) (r 2 » 0.81), with a tBAP/TRP ratio of 0.61 ± 0.24, indicating that TRP can be used as a conservative surrogate predictor of tBAP. A comparison of different operational categories for phosphorus indicated that sBAP is consistently lower than both soluble P (SP) and soluble reactive P (SRP) with average ratios of 0.34 ± 0.19 and 0.62 ± 0.27, respectively. This shows a large fraction of the dissolved non-reactive P (i.e., SP−SRP), and ≥40 % of the P classified as SRP was not bioavailable. Total BAP concentrations were on average 30 % higher than soluble BAP (sBAP) concentrations, indicating that the particulate P fraction was an important component of the BAP for the tested effluents. Comparisons between different P removal technologies suggest the BIOAVAILABILITY, and P species composition varies with the NUTRIENT removal process, and that in many cases, a large portion (>60 %) of the effluent P is recalcitrant to algal growth.