Biotechnological uses of purified and characterized alkaline cellulase from extremophilic Bacillus pumilus VLC7 from Lake Van

The present study focuses on the isolation and characterization of a bacterium from Lake Van adapted to an alkaline pH environment with significant cellulase production potential. The identified isolate, Bacillus pumilus VLC7 (GenBank Acc No: OR415888.1), exhibited the highest cellulase activity among other alkaliphilic isolates. The purification employing protein precipitation by ammonium sulfate, ultrafiltration, and ion exchange chromatography resulted in 20-fold purification with a specific activity of 16 U/mg protein. Cellulase had a molecular weight of 76 kDa, 3.13 mM K_m and 0.160 U/mg V_max values. The enzyme displayed maximum activity at pH 9.0 and 40 °C and retained at least 80% of its activity at temperatures of 25-60 °C for 90 min and pH 4-12 for one hour. Stability tests also revealed the enzyme's resilience to various reagents, metal ions, organic solvents, and detergents. Furthermore, the biotechnological applications of cellulase were explored, demonstrating its effectiveness in fabric biopolishing (removing pilling), as well as in the removal of fabric dyes. The research findings underscore the potential of B. pumilus VLC7 as a valuable source for eco-friendly industrial biotechnology applications.