Metabolic engineering of capsular polysaccharides.

Area of Science:

• Biotechnology
• Metabolic Engineering
• Microbial Engineering

Background:

• Growing demand for sustainable and reliable sources of capsular polysaccharides (CPSs) for biomedical applications.
• Traditional sources of CPSs are often toxic, unreliable, and inconsistent in product quality.
• Metabolic engineering offers a promising alternative for producing high-value CPSs.

Purpose of the Study:

• To review strategies for the metabolic engineering of four key CPSs: heparosan, chondroitin, hyaluronan, and polysialic acid.
• To highlight the potential of engineered microorganisms as cellular factories for CPS production.
• To discuss the application of these CPSs in various biomedical fields.

Main Methods:

• Exploitation of native CPS-producing microorganisms (wild-type and engineered).
• Development of genetically engineered heterologous hosts with improved or de novo pathways.
• Application of genetic engineering techniques such as gene knockout, promoter engineering, and gene expression control.

Main Results:

• Multiple-fold improvements in CPS fermentation titers compared to wild-type strains.
• Substantial increases in productivity, reaching up to 100% in some engineered strains.
• Demonstration of engineered microorganisms as industrially competitive alternatives to traditional sources.

Conclusions:

• Metabolic engineering provides effective strategies for producing important capsular polysaccharides.
• Engineered microbial cell factories offer a sustainable, reliable, and consistent source for biomedical applications.
• Optimization of these biotechnological processes is key to industrial adoption and replacing conventional methods.