Engineering Bacillus licheniformis as industrial chassis for efficient bioproduction from starch

Area of Science:

• Biotechnology
• Synthetic Biology
• Microbial Engineering

Background:

• Starch is a promising biorefinery feedstock, but its low natural conversion rate by microorganisms hinders industrial application.
• Efficient microbial conversion of starch is crucial for sustainable bioproduction.

Purpose of the Study:

• To systematically investigate and enhance the starch metabolic pathway in Bacillus licheniformis.
• To engineer B. licheniformis strains for improved starch utilization and increased production of valuable bioproducts.

Main Methods:

• Overexpression of amylolytic enzymes to improve starch hydrolysis.
• Modification of transmembrane transport systems for enhanced hydrolysate uptake.
• Engineering of intracellular degradation modules for accelerated conversion to glucose-6-phosphate.

Main Results:

• Engineered B. licheniformis DW2 strains demonstrated robust growth on starch.
• Productivity of bacitracin and subtilisin increased by 38.5% and 32.6%, respectively.
• Starch conversion rates for bacitracin and subtilisin improved by 32.3% and 22.9%, respectively.
• Another strain, B. licheniformis WX-02, achieved a 2.1-fold increase in starch conversion rate for poly-γ-glutamic acid production.

Conclusions:

• The study provides robust B. licheniformis chassis strains for sustainable bioproduction from starch.
• Engineering strategies for starch utilization can be applied to various B. licheniformis strains and bioproducts.
• This research advances the understanding of microbial substrate utilization for biorefinery applications.