Sustainable production of microbial phytase from animal faeces-derived Escherichia sp. via process optimization using response surface methodology

Abstract

The global phytase market is projected to reach USD 28.53 billion by 2035, reflecting substantial growth potential over the forecast period. The production of microbial phytase supports sustainable waste management; besides, enhances industrial and agricultural applicability by economically inducing enzyme yields. The study aimed to isolate phytase-producing bacteria from animal faeces and optimize phytase production using OFAT and Box-Behnken response surface methodology. The faeces are promising sources as it contains a diversity of microbes that are well adapted to phytate-rich diets; therefore, produce phytase. Escherichia sp. (CMDB5, PQ757147.1) was noted as the most promising phytase (4.241 ± 0.082 U/mL) yielding strain when using wheat bran as a substrate during fermentation. The physical parameters such as pH, temperature, incubation time, inoculum size, and aeration were assessed by OFAT approach followed by Duncan’s Tukey Post hoc test. Among these, temperature, pH and incubation time were selected for RSM approach. Based on the findings, maximum phytase yield (7.263 U/mL) was found at 40 °C, pH 7, and incubation for 4 days. The experimental yield corresponds to 103.27% of the model predicted values. Further, the interactions of these parameters suggested that pH was found to be the most influential factor for the enzyme yield ( p < 0.0001). The utilization of animal faeces as a microbial source and wheat bran as substrate underscores the potential of waste-derived resources for sustainable phytase production.