Molecular study on cloned endoglucanase gene from rumen bacterium

Area of Science:

• Microbiology
• Molecular Biology
• Biotechnology

Background:

• Endoglucanases are crucial enzymes for cellulose degradation.
• Efficient expression systems are needed to harness microbial enzyme potential.
• Ruminococcus flavefaciens is a key rumen bacterium with valuable enzymatic capabilities.

Purpose of the Study:

• To clone and express an endoglucanase gene from Ruminococcus flavefaciens.
• To evaluate expression levels in Escherichia coli and Streptococcus bovis JB1.
• To investigate the effect of different promoters on endoglucanase activity.

Main Methods:

• Subcloning of an endoglucanase gene from Ruminococcus flavefaciens strain 17.
• Insertion into pVA838-based shuttle vectors for expression in E. coli and S. bovis JB1.
• Utilizing the S. bovis JB1 alpha-amylase gene promoter (pACMCS) for endoglucanase expression.

Main Results:

• Maximal endoglucanase activities in S. bovis JB1/pVACMCI were 2- to 3-fold higher than in E. coli/pVACMCI.
• Specific cell activity in E. coli/pACMCS was 2- to 3-fold higher than in other E. coli constructs.
• Specific cell activity in S. bovis JB1/pACMCS was approximately 2-fold higher than in other S. bovis constructs.

Conclusions:

• The endoglucanase gene from Ruminococcus flavefaciens can be successfully expressed in E. coli and S. bovis JB1.
• The S. bovis JB1 alpha-amylase promoter (pACMCS) enhances endoglucanase expression and activity.
• S. bovis JB1 may serve as a more effective host for high-level endoglucanase production compared to E. coli under specific conditions.