UV/EMS mutagenized thermo-alkalophilic polygalacturonase from Glutamicibacter sp.: Physicochemical insights and biotechnological prospects

Abstract

The current study discusses the physicochemical properties of an alkalophilic polygalacturonase (PGmut) that was extracted from the UV/EMS mutagenized Glutamicibacter sp. MAIDO R22b-13 strain in comparison to its wildtype (PGwt). Further, its applications in various biotechnology sectors were also assessed. The PGwt and PGmut enzymes were purified by gel permeation chromatography and biochemical analysis determined them to be alkalophilic with pH optima of 10, however mutagenesis enhanced the temperature optima from 37 °C (PGwt) to 50 °C. The molecular weight of both enzymes was confirmed to be 48.67 kDa by SDS-PAGE and LC-MS. PGmut showed higher substrate affinity and velocity, with Km and Vmax of 0.051 mg/ml and 300.12 μmol/min, respectively, compared to 0.072 mg/ml and 205.30 μmol/min for PGwt. Co²⁺ and Mn²⁺ ions enhanced PGmut activity, while Ag²⁺, Cu²⁺, Hg²⁺, and EDTA lowered it. Nevertheless, dialysis-based EDTA removal moderately restored enzyme activity, confirming it to be a metalloenzyme. In addition, PGmut enhanced olive oil production, enabled lycopene extraction from tomato peels, and effectively softened sugarcane bagasse pulp for papermaking. Therefore, this study highlights PGmut's enhanced properties that offers cost-efficient, sustainable, time-saving bioprocess solution, benefiting industry and the environment.