Study and optimization of cellulase production in bacillus

زارعي بهجاني, زينب and زهري, دکتر صابر and اسدي, دکتر اسداله (2011) Study and optimization of cellulase production in bacillus. Masters thesis, University of Mohaghegh Ardabili.

Text پایان نامه.pdf Download (1MB)

Abstract

Cellulases are a group of hydrolytic enzymes which hydrolyze the glucosidic bonds of the cellulose and related cello-oligosaccharide derivatives. Cellulase has been used in detergents, the pulp and paper industry, animal feed, and even the food industry. Bacillus spp. are known to produce a variety of industrially important hydrolytic extracellular enzymes, such as cellulases. Among 48 isolates, only two colonies from the soil of Fandoghloo forest, were produced clear zones with 3.4 and 2.3 cm in diameter at cellulase screening medium, which were nominated as Z14 and Z19, respectively. The Z14 isolate was able to produce a very stable extracellular CMCase in the culture broth. The enzyme was active at natural pH and the optimum pH and temperature was estimated to 6 and 70 ˚C, respectively. By using Lineweaver - Burk plot Km and Vmax of the enzyme was determined as 2 mg/ml and 90.9 µmol/min/mg, respectively. The activity of enzyme was inhibited by EDTA, SDS, Ba2+, Mg2 +, Zn2+ and enhanced by Mn2+, Cu2+, Co2+, Fe3+. The molecular weight of the enzyme was estimated to 63.5 KDa using SDS-PAGE and Zymography. Purification of the enzyme using chitosan as an affinity ligand also showed 63.5 KDa band in SDS-PAGE gel, But during the process of purification, enzyme activity was lost. Since this enzyme could degrade native substrates such as straw and wheat bran, it has a potential application in animal feed and hydrolysis of the lignocellulosic material.

Actions (login required)

View Item