Tailoring fructooligosaccharides composition with engineered Zymomonas mobilis ZM4

Area of Science:

• Microbial biotechnology
• Synthetic biology
• Carbohydrate chemistry

Background:

• Zymomonas mobilis ZM4 is a promising host for producing valuable compounds like prebiotics.
• Fructooligosaccharides (FOS) are important prebiotics with health benefits.
• Developing efficient methods for FOS production is crucial for industrial applications.

Purpose of the Study:

• To establish a straightforward process for producing fructooligosaccharides (FOS) from sucrose using engineered Zymomonas mobilis.
• To control the composition of FOS mixtures by utilizing different enzymes (levansucrase and mutated β-fructofuranosidase).
• To optimize FOS production in a one-step fermentation process.

Main Methods:

• Engineering recombinant Zymomonas mobilis ZM4 strains to express either native levansucrase (sacB) or mutated β-fructofuranosidase (Ffase-Leu196).
• Fermentation of engineered strains using sucrose as a substrate.
• Analysis of FOS composition and quantification of production parameters (concentration, productivity, yield).

Main Results:

• Both engineered strains produced FOS mixtures, with a high concentration of 6-kestose.
• The Z. mobilis ZM4 pB1-sacB strain achieved the highest FOS production: 73.4 ± 1.6 g L⁻¹.
• This strain exhibited a productivity of 1.53 ± 0.03 g L⁻¹ h⁻¹ and a yield of 0.31 ± 0.03 g_FOS g_sucrose⁻¹.

Conclusions:

• Zymomonas mobilis can be effectively engineered for the one-step production of fructooligosaccharides (FOS).
• The use of specific enzymes allows for the control of FOS composition, favoring 6-kestose production.
• This study presents a novel and efficient route for producing tailor-made FOS mixtures using microbial fermentation.