Statistical optimization of Moringa oleifera Lam. leaf peroxidase activity and evaluation of its anti-bacterial and anti-oxidant functions

Peroxidases are haem-containing oxidoreductases with wide applications in biocatalysis, environmental remediation and health-related fields. In the present study, peroxidase was extracted from Moringa oleifera Lam. leaves and its extraction and reaction parameters were optimized using a one-variable-at-a-time (OVAT) approach. Furthermore, reaction parameters were statistically optimized using Response Surface Methodology (RSM). The effects of buffer type, molarity, pH, temperature, incubation time, substrate concentration and hydrogen peroxide levels were systematically evaluated. RSM modelling identified substrate volume (800 µL), buffer pH (6.0), temperature (25 °C) and guaiacol concentration (60 mM) as the most significant parameters, achieving a maximum peroxidase activity of 27.79 U/mL. The enzyme, under optimized reaction conditions, exhibited strong anti-bacterial potential by inhibiting bacterial growth. The crude extract also exhibited promising MIC values against the tested bacterial pathogens and demonstrated significant radical scavenging potential through hydrogen peroxide scavenging. These findings highlight Moringa oleifera Lam. leaf peroxidase as a cost-effective and eco-friendly biocatalyst with potential applications in anti-oxidant formulations, as an anti-bacterial agent and in biotechnological processes.