Adsorption of Methylene Blue onto Raw Wastes of Argan, Date, and Olive: Study of Kinetics and Isotherms

Environmental Engineering Science

Optimization of Carob (Ceratonia siliqua L.) Pulp Powder Roasting to Improve Its Quality by Using Central Composite Design

Food and Bioprocess Technology

Isolation and characterization of Lysobacter Enzymogene PS15 for Protease Production: Optimization Using Response Surface Methodology

<title>Abstract</title> In this study, a novel protease-producing strain, <italic>Lysobacter enzymogenes</italic> PS15, was successfully isolated from soil and identified through biochemical characterization and 16S rRNA gene sequencing. A sequential optimization strategy was employed to enhance protease yield. The one-factor-at-a-time (OFAT) method first determined an effective nutrient composition of 1.5% dextrose, 1.25% peptone, and 0.6% NaCl, and served as a screening tool to determine the suitable operational ranges for pH (6-8), temperature (34-46 °C), incubation time (12-60 h), and inoculum volume (0.25-3.25 %). These ranges were subsequently optimized using response surface methodology (RSM) using a central composite rotatable design (CCRD). The model predicted a maximum protease activity of 36.62 U mL ^-1 , which was experimentally confirmed at 35.09 U mL ^-1 under the optimal conditions (pH 7.0, 39 °C, 47 hours, and 2.3% inoculum volume). The crude enzyme exhibited optimal performance at 40 °C and pH 8, maintaining stability up to 45 °C. This work represents the first RSM-based optimization of protease production from <italic>L. enzymogenes</italic> , establishing its strong potential for diverse applications, including proteinaceous waste degradation and biocatalysis.