Enhanced Cellulase Production from Bacillus subtilis by Optimizing Physical Parameters for Bioethanol Production

Area of Science:

• Biotechnology
• Enzyme Engineering
• Microbial Fermentation

Background:

• Cellulase production by Bacillus subtilis AS3 is crucial for industrial applications.
• Optimization of physical parameters is key to maximizing enzyme yield and activity.
• Previous studies focused on medium composition, necessitating further investigation into physical factors.

Purpose of the Study:

• To investigate and optimize physical parameters (initial pH, agitation, temperature) for enhanced cellulase production from Bacillus subtilis AS3.
• To determine the optimal conditions for maximizing both cellulase activity and cell growth.
• To evaluate the efficacy of the optimized cellulase in bioethanol production.

Main Methods:

• Central composite design of experiments was employed to study the effects of physical parameters.
• Multiple desirability function was used for optimizing cellulase activity and cell growth.
• Scale-up studies were conducted in a bioreactor, and the enzyme was applied to bioethanol production using Zymomonas mobilis.

Main Results:

• Temperature and agitation significantly impacted cellulase production.
• Optimal conditions predicted were pH 7.2, 39°C, and 121 rpm, yielding 0.56 U/mL activity.
• A 33% enhancement in CMCase activity (0.57 U/mL) was achieved post-optimization.
• Scale-up in a bioreactor resulted in 0.75 U/mL activity.
• Bioethanol production yielded up to 11.65 g/L in bioreactors using optimized cellulase.

Conclusions:

• The study successfully optimized physical parameters for enhanced cellulase production by Bacillus subtilis AS3.
• Optimized cellulase demonstrated significant potential for efficient bioethanol production from lignocellulosic biomass.
• The findings provide a foundation for industrial-scale cellulase production and its application in biofuel generation.