Production of detergent stable thermophilic alkaline protease by Bacillus licheniformis ALW1

The growing industrial applications of alkaline proteases urged the production of highly active stable enzymes. In the current study, the enzyme production was achieved by submerged fermentation using the bacterial strain Bacillus licheniformis ALW1 that was further optimized to reach 22.903U/mL. The overall optimization fold was 46.7, achieved under the optimized fermentation medium composed of (%) molasses; 8, (NH4)2SO4; 0.45, wheat bran; 5, MgSO4·7H2O; 0.2, KH2PO4; 0.4, NaCl; 0.2 adjusted at pH 8 and incubated for 7days at 37 °C and 280 rpm. Additionally, the enzyme activity after partial purification was optimized by studying the effect of pH and temperature as well as the substrate concentration. The results indicated that the enzyme optimum activity was achieved at pH 9 and 70 °C with Km, Vmax and Kcat values of 3.846 mg/mL, 76.923U/mL/min and 1.206min−1 respectively. Thermal stability study of the partial pure enzyme indicated the half live times of the enzyme as 693.15, 231.05 and 57.76 min−1 at 55, 60 and 65 °C respectively, confirming its thermo-stability. Finally, the efficacy of the partial pure enzyme as a detergent additive was examined. The enzyme retained more than 80% of its activity with an efficient washing performance in the removal of blood stain after 30 min at 50 °C in addition to a commercial detergent. •Economic production of highly active alkaline protease using Bacillus licheniformis ALW1.•The partial pure enzyme was thermophilic and possessed high stability in commercial detergent.•The enzyme was added in the detergent formulation and applied for the removal of blood stain.