Streptomyces nodosus host strains optimized for polyene glycosylation engineering

Area of Science:

• Biochemistry and Molecular Biology
• Microbial Biotechnology
• Natural Product Synthesis

Background:

• Amphotericin B is a vital antifungal agent, with its biosynthesis involving complex enzymatic pathways.
• The AmphDI glycosyltransferase is key in transferring a sugar moiety to the amphotericin B aglycone, 8-deoxyamphoteronolide B.
• Understanding and manipulating these pathways are crucial for developing new antifungal therapies and improving production.

Purpose of the Study:

• To investigate the role of the AmphDI glycosyltransferase in amphotericin B biosynthesis.
• To engineer Streptomyces nodosus strains for enhanced production of amphotericin B aglycones.
• To generate novel aglycones for potential use in glycosylation engineering and drug discovery.

Main Methods:

• Inactivation of the amphDI gene in Streptomyces nodosus strains that already lacked the AmphN cytochrome P450.
• Cultivation of engineered strains to assess the production of amphotericin B derivatives.
• Analysis of the resulting aglycones using biochemical and genetic techniques.

Main Results:

• Successful inactivation of the amphDI gene was achieved in the modified Streptomyces nodosus.
• The engineered mutants produced 8-deoxy-16-methyl-16-descarboxyl amphoteronolides in high yields.
• This demonstrates a viable strategy for redirecting metabolic flux towards specific aglycone precursors.

Conclusions:

• The study successfully generated novel amphotericin B aglycones through targeted gene inactivation.
• These engineered strains and their products are valuable resources for future in vivo and in vitro glycosylation engineering efforts.
• This work provides a foundation for synthetic biology approaches to antifungal drug development.