Fig. 5.

Determination of optimal pH (a) and optimal temperature (b) of mRmMan5A and the variants derived using site-directed mutagenesis. The effect of pH on β-mannanase activity was determined in 50 mmol L⁻¹ of different buffers at optimal temperature of each enzyme. For optimal temperature, activity was measured at different temperatures in 50 mmol L⁻¹ McIlvaine buffer (optimal pH of each enzyme). The specific activities of mRmMan5A (9671.4 U mg⁻¹), variant Tyr233His (9834.6 U mg⁻¹), variant Lys264Met (10,139.5 U mg⁻¹), variant Asn343Ser (10,849.1 U mg⁻¹), and variant Tyr233His/Lys264Met (9942.8 U mg⁻¹) were considered as 100% in determinate the optimal pH and optimal temperature