Related Experiment Videos
Studies on Cellulose Hydrolysis by Acetivibrio cellulolyticus
C R Mackenzie1, D Bilous, G B Patel
1Division of Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6.
Applied and Environmental Microbiology
|August 1, 1985
Summary
Acetivibrio cellulolyticus cellulase effectively hydrolyzes crystalline cellulose when desalted and supplemented with calcium (Ca), which enhances enzyme stability. Without Ca, crystalline cellulose hydrolysis capacity is lost, though amorphous cellulose hydrolysis remains unaffected.
Area of Science:
- Biochemistry
- Enzymology
- Microbial Biotechnology
Background:
- Extracellular cellulases are crucial for biomass degradation.
- Crystalline cellulose hydrolysis presents a significant challenge in enzymatic processes.
- Understanding cellulase function and stability is key for industrial applications.
Purpose of the Study:
- To investigate the role of calcium (Ca) in the activity and stability of Acetivibrio cellulolyticus extracellular cellulase.
- To characterize the hydrolysis of crystalline cellulose by A. cellulolyticus cellulase.
- To compare the performance of A. cellulolyticus cellulase with Trichoderma reesei cellulase.
Main Methods:
- Enzyme activity assays on crystalline and amorphous cellulose.
- Effect of desalting and calcium supplementation on enzyme hydrolysis.
- Enzyme adsorption studies to Avicel at 40°C.
- Protein profiling of bound enzyme using SDS-PAGE.
Main Results:
- A. cellulolyticus cellulase extensively hydrolyzed desalted Avicel only when supplemented with Ca.
- Calcium significantly increased enzyme stability and retained crystalline cellulose hydrolysis capacity.
- Preincubation without Ca led to near-complete loss of crystalline cellulose hydrolysis.
- High adsorption of the Avicel-solubilizing component to crystalline cellulose was observed, distinct from endoglucanase and total protein adsorption.
Conclusions:
- Calcium is essential for the stability and crystalline cellulose hydrolyzing activity of A. cellulolyticus extracellular cellulase.
- The enzyme's ability to degrade crystalline cellulose is linked to specific component adsorption.
- A. cellulolyticus cellulase shows distinct properties compared to T. reesei cellulase for crystalline cellulose hydrolysis.