The optimization of thermostable recombinant α-amylase for efficient fabric desizing using response surface...

Area of Science:

• Biotechnology
• Enzyme Engineering
• Textile Chemistry

Background:

• Thermostable enzymes are crucial for industrial processes operating at high temperatures.
• Bacillus licheniformis is a known source of industrially relevant enzymes, including amylases.
• Developing eco-friendly enzymes for textile applications is a growing area of research.

Purpose of the Study:

• To clone and express a thermostable alpha-amylase (Amyk4) from Bacillus licheniformis in Escherichia coli.
• To characterize the enzymatic properties of the recombinant Amyk4, focusing on its thermostability and optimal activity conditions.
• To optimize and evaluate the performance of Amyk4 for cotton fabric desizing using Response Surface Methodology.

Main Methods:

• Gene cloning and expression of Amyk4 in E. coli BL21(DE3).
• Enzyme purification and characterization of optimal activity, pH, temperature, and stability.
• Response Surface Methodology (Box-Behnken design) for optimizing cotton fabric desizing.
• Scanning Electron Microscopy (SEM) for analyzing fabric surface after desizing.

Main Results:

• Recombinant Amyk4 showed maximal activity at 80°C and pH 6.0, with a half-life of over 30 hours.
• Optimal desizing conditions (pH 6.9, 80°C, 190 U/g enzyme, 95 min) yielded a TEGEWA rating of 8 and 6.6% weight loss.
• Statistical analysis confirmed the model's validity (R² > 0.91) and identified pH, enzyme concentration, and time as significant factors.
• SEM confirmed efficient starch removal without damaging cotton fibers.

Conclusions:

• The recombinant Amyk4 is a highly thermostable enzyme suitable for high-temperature industrial applications.
• Amyk4 demonstrates significant potential as an effective and eco-friendly agent for sustainable textile desizing.
• Optimization using RSM successfully identified conditions for efficient desizing, highlighting the enzyme's practical applicability.